Commit 23122b32 authored by Dmitry Frank's avatar Dmitry Frank Committed by rojer

Remove old docs, rename docs_new to docs

It would be probably good idea to also remove tools/docgen.py and
asciidoc.mk, but asciidoc.mk is still mentioned under `cloud/doc`, which
may contain some useful info which we'll need at least to review before
removing.

PUBLISHED_FROM=faf454d4c52a2f07ea8ac084cf0bd11a0c9c9b3b
parent f443c643
---
title: Disabling flags
---
- `MG_DISABLE_HTTP_WEBSOCKET` disable HTTP + Websocket protocol support
- `MG_DISABLE_HTTP_DIGEST_AUTH` disable HTTP Digest (MD5) authorization support
- `MG_DISABLE_MQTT` disable MQTT support
- `MG_DISABLE_SHA1` disable SHA1 support (used by Websocket)
- `MG_DISABLE_MD5` disable MD5 support (used by HTTP auth)
- `MG_DISABLE_JSON_RPC` disable JSON-RPC support
- `MG_DISABLE_SOCKETPAIR` disable `mg_broadcast()` API
- `MG_DISABLE_HTTP_KEEP_ALIVE` useful for embedded systems to save resources
---
title: Enabling flags
---
- `MG_ENABLE_SSL` Enable OpenSSL support
- `MG_ENABLE_IPV6` Enable IPV6 support
- `MG_ENABLE_THREADS` enable `mg_start_thread()` API
- `MG_ENABLE_MQTT_BROKER` enable MQTT broker
- `MG_ENABLE_DNS_SERVER` enable DNS server
- `MG_ENABLE_COAP` enable CoAP protocol
- `MG_ENABLE_GETADDRINFO` enable `getaddrinfo()` in `mg_resolve2()`
---
title: Build Options
---
Mongoose source code ships in a single .c file that contains functionality
for all supported protocols (modules). Modules can be disabled at compile
time which reduces executable size. That can be done by setting preprocessor
flags. Also, some preprocessor flags can be used to tune internal Mongoose
parameters.
To set a preprocessor flag during compile time, use `-D <PREPROCESSOR_FLAG>`
compiler option. For example, to disable both MQTT and JSON-RPC,
compile the application `my_app.c` like this (assumed UNIX system):
```
$ cc my_app.c mongoose.c -D MG_DISABLE_MQTT -D MG_DISABLE_JSON_RPC
```
{
"items": [
{ "type": "markdown", "name": "intro.md" },
{ "type": "markdown", "name": "enabling-flags.md" },
{ "type": "markdown", "name": "disabling-flags.md" },
{ "type": "markdown", "name": "platform-spec.md" },
{ "type": "markdown", "name": "tunables.md" }
]
}
---
title: Platform specific
---
Mongoose tries to detect the target platform whenever possible, but in some cases you have
to explicitly declare some peculiarities of your target, such as:
- `MG_LWIP`: use LWIP networking stack
- `MG_CC3200`: enable workarounds for the TI CC3200 target.
- `MG_ESP8266`: enable workarounds for the ESP8266 target, add `RTOS_SDK` to specify the RTOS SDK flavour.
---
title: Tunables
---
- `MG_MALLOC`, `MG_CALLOC`, `MG_REALLOC`, `MG_FREE` allow to use custom
memory allocator, e.g. `-DMG_MALLOC=my_malloc`
- `MG_USE_READ_WRITE` when set replaces calls to `recv` with `read` and `send` with `write`,
thus enabling to add any kind of file descriptor (files, serial devices) to an event manager.
- `MG_SSL_CRYPTO_MODERN`, `MG_SSL_CRYPTO_OLD` - choose either "Modern" or "Old" ciphers
instead of the default "Intermediate" setting.
See [this article](https://wiki.mozilla.org/Security/Server_Side_TLS#Recommended_configurations) for details.
== Build Options
Mongoose source code ships in a single .c file that contains functionality
for all supported protocols (modules). Modules can be disabled at compile
time which reduces executable size. That can be done by setting preprocessor
flags. Also, some preprocessor flags can be used to tune internal Mongoose
parameters.
To set a preprocessor flag during compile time, use `-D <PREPROCESSOR_FLAG>`
compiler option. For example, to disable both MQTT and JSON-RPC,
compile the application `my_app.c` like this (assumed UNIX system):
```
$ cc my_app.c mongoose.c -D MG_DISABLE_MQTT -D MG_DISABLE_JSON_RPC
```
=== Enabling flags
- `MG_ENABLE_SSL` Enable OpenSSL support
- `MG_ENABLE_IPV6` Enable IPV6 support
- `MG_ENABLE_THREADS` enable `mg_start_thread()` API
- `MG_ENABLE_MQTT_BROKER` enable MQTT broker
- `MG_ENABLE_DNS_SERVER` enable DNS server
- `MG_ENABLE_COAP` enable CoAP protocol
- `MG_ENABLE_GETADDRINFO` enable `getaddrinfo()` in `mg_resolve2()`
=== Disabling flags
- `MG_DISABLE_HTTP_WEBSOCKET` disable HTTP + Websocket protocol support
- `MG_DISABLE_HTTP_DIGEST_AUTH` disable HTTP Digest (MD5) authorization support
- `MG_DISABLE_MQTT` disable MQTT support
- `MG_DISABLE_SHA1` disable SHA1 support (used by Websocket)
- `MG_DISABLE_MD5` disable MD5 support (used by HTTP auth)
- `MG_DISABLE_JSON_RPC` disable JSON-RPC support
- `MG_DISABLE_SOCKETPAIR` disable `mg_broadcast()` API
- `MG_DISABLE_HTTP_KEEP_ALIVE` useful for embedded systems to save resources
=== Platform specific
Mongoose tries to detect the target platform whenever possible, but in some cases you have
to explicitly declare some peculiarities of your target, such as:
- `MG_LWIP`: use LWIP networking stack
- `MG_CC3200`: enable workarounds for the TI CC3200 target.
- `MG_ESP8266`: enable workarounds for the ESP8266 target, add `RTOS_SDK` to specify the RTOS SDK flavour.
=== Tunables
- `MG_MALLOC`, `MG_CALLOC`, `MG_REALLOC`, `MG_FREE` allow to use custom
memory allocator, e.g. `-DMG_MALLOC=my_malloc`
- `MG_USE_READ_WRITE` when set replaces calls to `recv` with `read` and `send` with `write`,
thus enabling to add any kind of file descriptor (files, serial devices) to an event manager.
- `MG_SSL_CRYPTO_MODERN`, `MG_SSL_CRYPTO_OLD` - choose either "Modern" or "Old" ciphers
instead of the default "Intermediate" setting.
See [this article](https://wiki.mozilla.org/Security/Server_Side_TLS#Recommended_configurations) for details.
---
title: "CoAP"
symbol_kind: "intro"
decl_name: "coap.h"
---
CoAP message format:
```
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
|Ver| T | TKL | Code | Message ID | Token (if any, TKL bytes) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Options (if any) ... |1 1 1 1 1 1 1 1| Payload (if any) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
```
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_set_protocol_coap.md"
},
{
"type": "markdown",
"name": "mg_coap_add_option.md"
},
{
"type": "markdown",
"name": "mg_coap_free_options.md"
},
{
"type": "markdown",
"name": "mg_coap_send_message.md"
},
{
"type": "markdown",
"name": "mg_coap_send_ack.md"
},
{
"type": "markdown",
"name": "mg_coap_parse.md"
},
{
"type": "markdown",
"name": "mg_coap_compose.md"
},
{
"type": "markdown",
"name": "struct_mg_coap_option.md"
},
{
"type": "markdown",
"name": "struct_mg_coap_message.md"
}
]
}
---
title: "mg_coap_add_option()"
decl_name: "mg_coap_add_option"
symbol_kind: "func"
signature: |
struct mg_coap_option *mg_coap_add_option(struct mg_coap_message *cm,
uint32_t number, char *value,
size_t len);
---
Add new option to mg_coap_message structure.
Returns pointer to the newly created option.
---
title: "mg_coap_compose()"
decl_name: "mg_coap_compose"
symbol_kind: "func"
signature: |
uint32_t mg_coap_compose(struct mg_coap_message *cm, struct mbuf *io);
---
Composes CoAP message from mg_coap_message structure.
This is a helper function.
Return value: see `mg_coap_send_message()`
---
title: "mg_coap_free_options()"
decl_name: "mg_coap_free_options"
symbol_kind: "func"
signature: |
void mg_coap_free_options(struct mg_coap_message *cm);
---
Free the memory allocated for options,
if cm paramater doesn't contain any option does nothing.
---
title: "mg_coap_parse()"
decl_name: "mg_coap_parse"
symbol_kind: "func"
signature: |
uint32_t mg_coap_parse(struct mbuf *io, struct mg_coap_message *cm);
---
Parse COAP message and fills mg_coap_message and returns cm->flags.
This is a helper function.
NOTE: usually CoAP work over UDP, so lack of data means format error,
but in theory it is possible to use CoAP over TCP (according to RFC)
The caller have to check results and treat COAP_NOT_ENOUGH_DATA according to
underlying protocol:
- in case of UDP COAP_NOT_ENOUGH_DATA means COAP_FORMAT_ERROR,
- in case of TCP client can try to receive more data
Return value: see `mg_coap_send_message()`
---
title: "mg_coap_send_ack()"
decl_name: "mg_coap_send_ack"
symbol_kind: "func"
signature: |
uint32_t mg_coap_send_ack(struct mg_connection *nc, uint16_t msg_id);
---
Compose CoAP acknowledgement from `mg_coap_message`
and send it into `nc` connection.
Return value: see `mg_coap_send_message()`
---
title: "mg_coap_send_message()"
decl_name: "mg_coap_send_message"
symbol_kind: "func"
signature: |
uint32_t mg_coap_send_message(struct mg_connection *nc,
struct mg_coap_message *cm);
---
Compose CoAP message from `mg_coap_message`
and send it into `nc` connection.
Return 0 on success. On error, it is a bitmask:
- `#define MG_COAP_ERROR 0x10000`
- `#define MG_COAP_FORMAT_ERROR (MG_COAP_ERROR | 0x20000)`
- `#define MG_COAP_IGNORE (MG_COAP_ERROR | 0x40000)`
- `#define MG_COAP_NOT_ENOUGH_DATA (MG_COAP_ERROR | 0x80000)`
- `#define MG_COAP_NETWORK_ERROR (MG_COAP_ERROR | 0x100000)`
---
title: "mg_set_protocol_coap()"
decl_name: "mg_set_protocol_coap"
symbol_kind: "func"
signature: |
int mg_set_protocol_coap(struct mg_connection *nc);
---
Set CoAP protocol handler - trigger CoAP specific events
---
title: "struct mg_coap_message"
decl_name: "struct mg_coap_message"
symbol_kind: "struct"
signature: |
struct mg_coap_message {
uint32_t flags;
uint8_t msg_type;
uint8_t code_class;
uint8_t code_detail;
uint16_t msg_id;
struct mg_str token;
struct mg_coap_option *options;
struct mg_str payload;
struct mg_coap_option *optiomg_tail;
};
---
CoAP message. See RFC 7252 for details.
---
title: "struct mg_coap_option"
decl_name: "struct mg_coap_option"
symbol_kind: "struct"
signature: |
struct mg_coap_option {
struct mg_coap_option *next;
uint32_t number;
struct mg_str value;
};
---
CoAP options.
Use mg_coap_add_option and mg_coap_free_options
for creation and destruction.
---
title: "DNS server"
symbol_kind: "intro"
decl_name: "dns-server.h"
---
Disabled by default; enable with `-DMG_ENABLE_DNS_SERVER`.
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_dns_create_reply.md"
},
{
"type": "markdown",
"name": "mg_dns_reply_record.md"
},
{
"type": "markdown",
"name": "mg_dns_send_reply.md"
}
]
}
---
title: "mg_dns_create_reply()"
decl_name: "mg_dns_create_reply"
symbol_kind: "func"
signature: |
struct mg_dns_reply mg_dns_create_reply(struct mbuf *io,
struct mg_dns_message *msg);
---
Create a DNS reply.
The reply will be based on an existing query message `msg`.
The query body will be appended to the output buffer.
"reply + recursion allowed" will be added to the message flags and
message's num_answers will be set to 0.
Answer records can be appended with `mg_dns_send_reply` or by lower
level function defined in the DNS API.
In order to send the reply use `mg_dns_send_reply`.
It's possible to use a connection's send buffer as reply buffers,
and it will work for both UDP and TCP connections.
Example:
```c
reply = mg_dns_create_reply(&nc->send_mbuf, msg);
for (i = 0; i < msg->num_questions; i++) {
rr = &msg->questions[i];
if (rr->rtype == MG_DNS_A_RECORD) {
mg_dns_reply_record(&reply, rr, 3600, &dummy_ip_addr, 4);
}
}
mg_dns_send_reply(nc, &reply);
```
---
title: "mg_dns_reply_record()"
decl_name: "mg_dns_reply_record"
symbol_kind: "func"
signature: |
int mg_dns_reply_record(struct mg_dns_reply *reply,
struct mg_dns_resource_record *question,
const char *name, int rtype, int ttl, const void *rdata,
size_t rdata_len);
---
Append a DNS reply record to the IO buffer and to the DNS message.
The message num_answers field will be incremented. It's caller's duty
to ensure num_answers is propertly initialized.
Returns -1 on error.
---
title: "mg_dns_send_reply()"
decl_name: "mg_dns_send_reply"
symbol_kind: "func"
signature: |
void mg_dns_send_reply(struct mg_connection *nc, struct mg_dns_reply *r);
---
Send a DNS reply through a connection.
The DNS data is stored in an IO buffer pointed by reply structure in `r`.
This function mutates the content of that buffer in order to ensure that
the DNS header reflects size and flags of the mssage, that might have been
updated either with `mg_dns_reply_record` or by direct manipulation of
`r->message`.
Once sent, the IO buffer will be trimmed unless the reply IO buffer
is the connection's send buffer and the connection is not in UDP mode.
---
title: "DNS"
symbol_kind: "intro"
decl_name: "dns.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_dns_parse_record_data.md"
},
{
"type": "markdown",
"name": "mg_send_dns_query.md"
},
{
"type": "markdown",
"name": "mg_dns_insert_header.md"
},
{
"type": "markdown",
"name": "mg_dns_copy_questions.md"
},
{
"type": "markdown",
"name": "mg_dns_encode_record.md"
},
{
"type": "markdown",
"name": "mg_parse_dns.md"
},
{
"type": "markdown",
"name": "mg_dns_uncompress_name.md"
},
{
"type": "markdown",
"name": "mg_set_protocol_dns.md"
},
{
"type": "markdown",
"name": "struct_mg_dns_resource_record.md"
},
{
"type": "markdown",
"name": "struct_mg_dns_message.md"
}
]
}
---
title: "mg_dns_copy_questions()"
decl_name: "mg_dns_copy_questions"
symbol_kind: "func"
signature: |
int mg_dns_copy_questions(struct mbuf *io, struct mg_dns_message *msg);
---
Append already encoded questions from an existing message.
This is useful when generating a DNS reply message which includes
all question records.
Return number of appened bytes.
---
title: "mg_dns_encode_record()"
decl_name: "mg_dns_encode_record"
symbol_kind: "func"
signature: |
int mg_dns_encode_record(struct mbuf *io, struct mg_dns_resource_record *rr,
const char *name, size_t nlen, const void *rdata,
size_t rlen);
---
Encode and append a DNS resource record to an IO buffer.
The record metadata is taken from the `rr` parameter, while the name and data
are taken from the parameters, encoded in the appropriate format depending on
record type, and stored in the IO buffer. The encoded values might contain
offsets within the IO buffer. It's thus important that the IO buffer doesn't
get trimmed while a sequence of records are encoded while preparing a DNS
*reply.
This function doesn't update the `name` and `rdata` pointers in the `rr`
*struct
because they might be invalidated as soon as the IO buffer grows again.
Return the number of bytes appened or -1 in case of error.
---
title: "mg_dns_insert_header()"
decl_name: "mg_dns_insert_header"
symbol_kind: "func"
signature: |
int mg_dns_insert_header(struct mbuf *io, size_t pos,
struct mg_dns_message *msg);
---
Insert a DNS header to an IO buffer.
Return number of bytes inserted.
---
title: "mg_dns_parse_record_data()"
decl_name: "mg_dns_parse_record_data"
symbol_kind: "func"
signature: |
int mg_dns_parse_record_data(struct mg_dns_message *msg,
struct mg_dns_resource_record *rr, void *data,
size_t data_len);
---
Parse the record data from a DNS resource record.
- A: struct in_addr *ina
- AAAA: struct in6_addr *ina
- CNAME: char buffer
Returns -1 on error.
TODO(mkm): MX
---
title: "mg_dns_uncompress_name()"
decl_name: "mg_dns_uncompress_name"
symbol_kind: "func"
signature: |
size_t mg_dns_uncompress_name(struct mg_dns_message *msg, struct mg_str *name,
char *dst, int dst_len);
---
Uncompress a DNS compressed name.
The containing dns message is required because the compressed encoding
and reference suffixes present elsewhere in the packet.
If name is less than `dst_len` characters long, the remainder
of `dst` is terminated with `\0' characters. Otherwise, `dst` is not
*terminated.
If `dst_len` is 0 `dst` can be NULL.
Return the uncompressed name length.
---
title: "mg_parse_dns()"
decl_name: "mg_parse_dns"
symbol_kind: "func"
signature: |
int mg_parse_dns(const char *buf, int len, struct mg_dns_message *msg);
---
Low-level: parses a DNS response.
---
title: "mg_send_dns_query()"
decl_name: "mg_send_dns_query"
symbol_kind: "func"
signature: |
void mg_send_dns_query(struct mg_connection *nc, const char *name,
int query_type);
---
Send a DNS query to the remote end.
---
title: "mg_set_protocol_dns()"
decl_name: "mg_set_protocol_dns"
symbol_kind: "func"
signature: |
void mg_set_protocol_dns(struct mg_connection *nc);
---
Attach built-in DNS event handler to the given listening connection.
DNS event handler parses incoming UDP packets, treating them as DNS
requests. If incoming packet gets successfully parsed by the DNS event
handler, a user event handler will receive `MG_DNS_REQUEST` event, with
`ev_data` pointing to the parsed `struct mg_dns_message`.
See
[captive_dns_server](https://github.com/cesanta/mongoose/tree/master/examples/captive_dns_server)
example on how to handle DNS request and send DNS reply.
---
title: "struct mg_dns_message"
decl_name: "struct mg_dns_message"
symbol_kind: "struct"
signature: |
struct mg_dns_message {
struct mg_str pkt; /* packet body */
uint16_t flags;
uint16_t transaction_id;
int num_questions;
int num_answers;
struct mg_dns_resource_record questions[MG_MAX_DNS_QUESTIONS];
struct mg_dns_resource_record answers[MG_MAX_DNS_ANSWERS];
};
---
DNS message (request and response).
---
title: "struct mg_dns_resource_record"
decl_name: "struct mg_dns_resource_record"
symbol_kind: "struct"
signature: |
struct mg_dns_resource_record {
struct mg_str name; /* buffer with compressed name */
int rtype;
int rclass;
int ttl;
enum mg_dns_resource_record_kind kind;
struct mg_str rdata; /* protocol data (can be a compressed name) */
};
---
DNS resource record.
---
title: "HTTP + Websocket"
symbol_kind: "intro"
decl_name: "http.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_set_protocol_http_websocket.md"
},
{
"type": "markdown",
"name": "mg_send_websocket_handshake.md"
},
{
"type": "markdown",
"name": "mg_send_websocket_handshake2.md"
},
{
"type": "markdown",
"name": "mg_connect_ws.md"
},
{
"type": "markdown",
"name": "mg_connect_ws_opt.md"
},
{
"type": "markdown",
"name": "mg_send_websocket_frame.md"
},
{
"type": "markdown",
"name": "mg_send_websocket_framev.md"
},
{
"type": "markdown",
"name": "mg_printf_websocket_frame.md"
},
{
"type": "markdown",
"name": "mg_send_http_chunk.md"
},
{
"type": "markdown",
"name": "mg_printf_http_chunk.md"
},
{
"type": "markdown",
"name": "mg_send_response_line.md"
},
{
"type": "markdown",
"name": "mg_send_head.md"
},
{
"type": "markdown",
"name": "mg_printf_html_escape.md"
},
{
"type": "markdown",
"name": "mg_parse_http.md"
},
{
"type": "markdown",
"name": "mg_get_http_header.md"
},
{
"type": "markdown",
"name": "mg_http_parse_header.md"
},
{
"type": "markdown",
"name": "mg_parse_multipart.md"
},
{
"type": "markdown",
"name": "mg_get_http_var.md"
},
{
"type": "markdown",
"name": "mg_url_decode.md"
},
{
"type": "markdown",
"name": "mg_http_create_digest_auth_header.md"
},
{
"type": "markdown",
"name": "mg_connect_http.md"
},
{
"type": "markdown",
"name": "mg_connect_http_opt.md"
},
{
"type": "markdown",
"name": "mg_serve_http.md"
},
{
"type": "markdown",
"name": "mg_register_http_endpoint.md"
},
{
"type": "markdown",
"name": "mg_file_upload_handler.md"
},
{
"type": "markdown",
"name": "mg_fu_fname_fn.md"
},
{
"type": "markdown",
"name": "struct_http_message.md"
},
{
"type": "markdown",
"name": "struct_websocket_message.md"
},
{
"type": "markdown",
"name": "struct_mg_http_multipart_part.md"
},
{
"type": "markdown",
"name": "struct_mg_serve_http_opts.md"
}
]
}
---
title: "mg_connect_http()"
decl_name: "mg_connect_http"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect_http(struct mg_mgr *mgr,
mg_event_handler_t event_handler,
const char *url,
const char *extra_headers,
const char *post_data);
---
Helper function that creates outbound HTTP connection.
`url` is a URL to fetch. It must be properly URL-encoded, e.g. have
no spaces, etc. By default, `mg_connect_http()` sends Connection and
Host headers. `extra_headers` is an extra HTTP headers to send, e.g.
`"User-Agent: my-app\r\n"`.
If `post_data` is NULL, then GET request is created. Otherwise, POST request
is created with the specified POST data. Note that if the data being posted
is a form submission, the `Content-Type` header should be set accordingly
(see example below).
Examples:
```c
nc1 = mg_connect_http(mgr, ev_handler_1, "http://www.google.com", NULL,
NULL);
nc2 = mg_connect_http(mgr, ev_handler_1, "https://github.com", NULL, NULL);
nc3 = mg_connect_http(
mgr, ev_handler_1, "my_server:8000/form_submit/",
"Content-Type: application/x-www-form-urlencoded\r\n",
"var_1=value_1&var_2=value_2");
```
---
title: "mg_connect_http_opt()"
decl_name: "mg_connect_http_opt"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect_http_opt(struct mg_mgr *mgr,
mg_event_handler_t ev_handler,
struct mg_connect_opts opts,
const char *url,
const char *extra_headers,
const char *post_data);
---
Helper function that creates outbound HTTP connection.
Mostly identical to mg_connect_http, but allows to provide extra parameters
(for example, SSL parameters
---
title: "mg_connect_ws()"
decl_name: "mg_connect_ws"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect_ws(struct mg_mgr *mgr,
mg_event_handler_t event_handler,
const char *url, const char *protocol,
const char *extra_headers);
---
Helper function that creates an outbound WebSocket connection.
`url` is a URL to connect to. It must be properly URL-encoded, e.g. have
no spaces, etc. By default, `mg_connect_ws()` sends Connection and
Host headers. `extra_headers` is an extra HTTP headers to send, e.g.
`"User-Agent: my-app\r\n"`.
If `protocol` is not NULL, then a `Sec-WebSocket-Protocol` header is sent.
Examples:
```c
nc1 = mg_connect_ws(mgr, ev_handler_1, "ws://echo.websocket.org", NULL,
NULL);
nc2 = mg_connect_ws(mgr, ev_handler_1, "wss://echo.websocket.org", NULL,
NULL);
nc3 = mg_connect_ws(mgr, ev_handler_1, "ws://api.cesanta.com",
"clubby.cesanta.com", NULL);
```
---
title: "mg_connect_ws_opt()"
decl_name: "mg_connect_ws_opt"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect_ws_opt(struct mg_mgr *mgr,
mg_event_handler_t ev_handler,
struct mg_connect_opts opts,
const char *url, const char *protocol,
const char *extra_headers);
---
Helper function that creates an outbound WebSocket connection
Mostly identical to mg_connect_ws, but allows to provide extra parameters
(for example, SSL parameters
---
title: "mg_file_upload_handler()"
decl_name: "mg_file_upload_handler"
symbol_kind: "func"
signature: |
void mg_file_upload_handler(struct mg_connection *nc, int ev, void *ev_data,
mg_fu_fname_fn local_name_fn);
---
File upload handler.
This handler can be used to implement file uploads with minimum code.
This handler will process MG_EV_HTTP_PART_* events and store file data into
a local file.
`local_name_fn` will be invoked with whatever name was provided by the client
and will expect the name of the local file to open. Return value of NULL will
abort file upload (client will get a "403 Forbidden" response). If non-null,
the returned string must be heap-allocated and will be freed by the caller.
Exception: it is ok to return the same string verbatim.
Example:
```c
struct mg_str upload_fname(struct mg_connection *nc, struct mg_str fname) {
// Just return the same filename. Do not actually do this except in test!
// fname is user-controlled and needs to be sanitized.
return fname;
}
void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
switch (ev) {
...
case MG_EV_HTTP_PART_BEGIN:
case MG_EV_HTTP_PART_DATA:
case MG_EV_HTTP_PART_END:
mg_file_upload_handler(nc, ev, ev_data, upload_fname);
break;
}
}
```
---
title: "mg_fu_fname_fn"
decl_name: "mg_fu_fname_fn"
symbol_kind: "typedef"
signature: |
typedef struct mg_str (*mg_fu_fname_fn)(struct mg_connection *nc,
struct mg_str fname);
---
Callback prototype for `mg_file_upload_handler()`.
---
title: "mg_get_http_header()"
decl_name: "mg_get_http_header"
symbol_kind: "func"
signature: |
struct mg_str *mg_get_http_header(struct http_message *hm, const char *name);
---
Search and return header `name` in parsed HTTP message `hm`.
If header is not found, NULL is returned. Example:
struct mg_str *host_hdr = mg_get_http_header(hm, "Host");
---
title: "mg_get_http_var()"
decl_name: "mg_get_http_var"
symbol_kind: "func"
signature: |
int mg_get_http_var(const struct mg_str *buf, const char *name, char *dst,
size_t dst_len);
---
Fetch an HTTP form variable.
Fetch a variable `name` from a `buf` into a buffer specified by
`dst`, `dst_len`. Destination is always zero-terminated. Return length
of a fetched variable. If not found, 0 is returned. `buf` must be
valid url-encoded buffer. If destination is too small, `-1` is returned.
---
title: "mg_http_create_digest_auth_header()"
decl_name: "mg_http_create_digest_auth_header"
symbol_kind: "func"
signature: |
int mg_http_create_digest_auth_header(char *buf, size_t buf_len,
const char *method, const char *uri,
const char *auth_domain, const char *user,
const char *passwd);
---
Create Digest authentication header for client request.
---
title: "mg_http_parse_header()"
decl_name: "mg_http_parse_header"
symbol_kind: "func"
signature: |
int mg_http_parse_header(struct mg_str *hdr, const char *var_name, char *buf,
size_t buf_size);
---
Parse HTTP header `hdr`. Find variable `var_name` and store it's value
in the buffer `buf`, `buf_size`. Return 0 if variable not found, non-zero
otherwise.
This function is supposed to parse
cookies, authentication headers, etcetera. Example (error handling omitted):
char user[20];
struct mg_str *hdr = mg_get_http_header(hm, "Authorization");
mg_http_parse_header(hdr, "username", user, sizeof(user));
Return length of the variable's value. If buffer is not large enough,
or variable not found, 0 is returned.
---
title: "mg_parse_http()"
decl_name: "mg_parse_http"
symbol_kind: "func"
signature: |
int mg_parse_http(const char *s, int n, struct http_message *hm, int is_req);
---
Parse a HTTP message.
`is_req` should be set to 1 if parsing request, 0 if reply.
Return number of bytes parsed. If HTTP message is
incomplete, `0` is returned. On parse error, negative number is returned.
---
title: "mg_parse_multipart()"
decl_name: "mg_parse_multipart"
symbol_kind: "func"
signature: |
size_t mg_parse_multipart(const char *buf, size_t buf_len, char *var_name,
size_t var_name_len, char *file_name,
size_t file_name_len, const char **chunk,
size_t *chunk_len);
---
Parse buffer `buf`, `buf_len` that contains multipart form data chunks.
Store chunk name in a `var_name`, `var_name_len` buffer.
If a chunk is an uploaded file, then `file_name`, `file_name_len` is
filled with an uploaded file name. `chunk`, `chunk_len`
points to the chunk data.
Return: number of bytes to skip to the next chunk, or 0 if there are
no more chunks.
Usage example:
```c
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
switch(ev) {
case MG_EV_HTTP_REQUEST: {
struct http_message *hm = (struct http_message *) ev_data;
char var_name[100], file_name[100];
const char *chunk;
size_t chunk_len, n1, n2;
n1 = n2 = 0;
while ((n2 = mg_parse_multipart(hm->body.p + n1,
hm->body.len - n1,
var_name, sizeof(var_name),
file_name, sizeof(file_name),
&chunk, &chunk_len)) > 0) {
printf("var: %s, file_name: %s, size: %d, chunk: [%.*s]\n",
var_name, file_name, (int) chunk_len,
(int) chunk_len, chunk);
n1 += n2;
}
}
break;
```
---
title: "mg_printf_html_escape()"
decl_name: "mg_printf_html_escape"
symbol_kind: "func"
signature: |
void mg_printf_html_escape(struct mg_connection *nc, const char *fmt, ...);
---
Send printf-formatted HTTP chunk, escaping HTML tags.
---
title: "mg_printf_http_chunk()"
decl_name: "mg_printf_http_chunk"
symbol_kind: "func"
signature: |
void mg_printf_http_chunk(struct mg_connection *nc, const char *fmt, ...);
---
Send printf-formatted HTTP chunk.
Functionality is similar to `mg_send_http_chunk()`.
---
title: "mg_printf_websocket_frame()"
decl_name: "mg_printf_websocket_frame"
symbol_kind: "func"
signature: |
void mg_printf_websocket_frame(struct mg_connection *nc, int op_and_flags,
const char *fmt, ...);
---
Send websocket frame to the remote end.
Like `mg_send_websocket_frame()`, but allows to create formatted message
with `printf()`-like semantics.
---
title: "mg_register_http_endpoint()"
decl_name: "mg_register_http_endpoint"
symbol_kind: "func"
signature: |
void mg_register_http_endpoint(struct mg_connection *nc, const char *uri_path,
mg_event_handler_t handler);
---
Register callback for specified http endpoint
Note: if callback is registered it is called instead of
callback provided in mg_bind
Example code snippet:
```c
static void handle_hello1(struct mg_connection *nc, int ev, void *ev_data) {
(void) ev; (void) ev_data;
mg_printf(nc, "HTTP/1.0 200 OK\r\n\r\n[I am Hello1]");
nc->flags |= MG_F_SEND_AND_CLOSE;
}
static void handle_hello1(struct mg_connection *nc, int ev, void *ev_data) {
(void) ev; (void) ev_data;
mg_printf(nc, "HTTP/1.0 200 OK\r\n\r\n[I am Hello2]");
nc->flags |= MG_F_SEND_AND_CLOSE;
}
void init() {
nc = mg_bind(&mgr, local_addr, cb1);
mg_register_http_endpoint(nc, "/hello1", handle_hello1);
mg_register_http_endpoint(nc, "/hello1/hello2", handle_hello2);
}
```
---
title: "mg_send_head()"
decl_name: "mg_send_head"
symbol_kind: "func"
signature: |
void mg_send_head(struct mg_connection *n, int status_code,
int64_t content_length, const char *extra_headers);
---
Send response line and headers.
This function sends response line with the `status_code`, and automatically
sends one header: either "Content-Length", or "Transfer-Encoding".
If `content_length` is negative, then "Transfer-Encoding: chunked" header
is sent, otherwise, "Content-Length" header is sent.
NOTE: If `Transfer-Encoding` is `chunked`, then message body must be sent
using `mg_send_http_chunk()` or `mg_printf_http_chunk()` functions.
Otherwise, `mg_send()` or `mg_printf()` must be used.
Extra headers could be set through `extra_headers` - and note `extra_headers`
must NOT be terminated by a new line.
---
title: "mg_send_http_chunk()"
decl_name: "mg_send_http_chunk"
symbol_kind: "func"
signature: |
void mg_send_http_chunk(struct mg_connection *nc, const char *buf, size_t len);
---
Send buffer `buf` of size `len` to the client using chunked HTTP encoding.
This function first sends buffer size as hex number + newline, then
buffer itself, then newline. For example,
`mg_send_http_chunk(nc, "foo", 3)` whill append `3\r\nfoo\r\n` string to
the `nc->send_mbuf` output IO buffer.
NOTE: HTTP header "Transfer-Encoding: chunked" should be sent prior to
using this function.
NOTE: do not forget to send empty chunk at the end of the response,
to tell the client that everything was sent. Example:
```
mg_printf_http_chunk(nc, "%s", "my response!");
mg_send_http_chunk(nc, "", 0); // Tell the client we're finished
```
---
title: "mg_send_response_line()"
decl_name: "mg_send_response_line"
symbol_kind: "func"
signature: |
void mg_send_response_line(struct mg_connection *c, int status_code,
const char *extra_headers);
---
Send response status line.
If `extra_headers` is not NULL, then `extra_headers` are also sent
after the reponse line. `extra_headers` must NOT end end with new line.
Example:
mg_send_response_line(nc, 200, "Access-Control-Allow-Origin: *");
Will result in:
HTTP/1.1 200 OK\r\n
Access-Control-Allow-Origin: *\r\n
---
title: "mg_send_websocket_frame()"
decl_name: "mg_send_websocket_frame"
symbol_kind: "func"
signature: |
void mg_send_websocket_frame(struct mg_connection *nc, int op_and_flags,
const void *data, size_t data_len);
---
Send websocket frame to the remote end.
`op_and_flags` specifies frame's type, one of:
- WEBSOCKET_OP_CONTINUE
- WEBSOCKET_OP_TEXT
- WEBSOCKET_OP_BINARY
- WEBSOCKET_OP_CLOSE
- WEBSOCKET_OP_PING
- WEBSOCKET_OP_PONG
Orred with one of the flags:
- WEBSOCKET_DONT_FIN: Don't set the FIN flag on the frame to be sent.
`data` and `data_len` contain frame data.
---
title: "mg_send_websocket_framev()"
decl_name: "mg_send_websocket_framev"
symbol_kind: "func"
signature: |
void mg_send_websocket_framev(struct mg_connection *nc, int op_and_flags,
const struct mg_str *strings, int num_strings);
---
Send multiple websocket frames.
Like `mg_send_websocket_frame()`, but composes a frame from multiple buffers.
---
title: "mg_send_websocket_handshake()"
decl_name: "mg_send_websocket_handshake"
symbol_kind: "func"
signature: |
void mg_send_websocket_handshake(struct mg_connection *nc, const char *uri,
const char *extra_headers);
---
Send websocket handshake to the server.
`nc` must be a valid connection, connected to a server. `uri` is an URI
to fetch, extra_headers` is extra HTTP headers to send or `NULL`.
This function is intended to be used by websocket client.
Note that the Host header is mandatory in HTTP/1.1 and must be
included in `extra_headers`. `mg_send_websocket_handshake2` offers
a better API for that.
Deprecated in favour of `mg_send_websocket_handshake2`
---
title: "mg_send_websocket_handshake2()"
decl_name: "mg_send_websocket_handshake2"
symbol_kind: "func"
signature: |
void mg_send_websocket_handshake2(struct mg_connection *nc, const char *path,
const char *host, const char *protocol,
const char *extra_headers);
---
Send websocket handshake to the server.
`nc` must be a valid connection, connected to a server. `uri` is an URI
to fetch, `host` goes into the `Host` header, `protocol` goes into the
`Sec-WebSocket-Proto` header (NULL to omit), extra_headers` is extra HTTP
headers to send or `NULL`.
This function is intended to be used by websocket client.
---
title: "mg_serve_http()"
decl_name: "mg_serve_http"
symbol_kind: "func"
signature: |
void mg_serve_http(struct mg_connection *nc, struct http_message *hm,
struct mg_serve_http_opts opts);
---
Serve given HTTP request according to the `options`.
Example code snippet:
```c
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
struct http_message *hm = (struct http_message *) ev_data;
struct mg_serve_http_opts opts = { .document_root = "/var/www" }; // C99
switch (ev) {
case MG_EV_HTTP_REQUEST:
mg_serve_http(nc, hm, opts);
break;
default:
break;
}
}
```
---
title: "mg_set_protocol_http_websocket()"
decl_name: "mg_set_protocol_http_websocket"
symbol_kind: "func"
signature: |
void mg_set_protocol_http_websocket(struct mg_connection *nc);
---
Attach built-in HTTP event handler to the given connection.
User-defined event handler will receive following extra events:
- MG_EV_HTTP_REQUEST: HTTP request has arrived. Parsed HTTP request
is passed as
`struct http_message` through the handler's `void *ev_data` pointer.
- MG_EV_HTTP_MULTIPART_REQUEST: A multipart POST request has received.
This event is sent before body is parsed. After this user
should expect a sequence of MG_EV_HTTP_PART_BEGIN/DATA/END requests.
This is also the last time when headers and other request fields are
accessible.
- MG_EV_HTTP_REPLY: HTTP reply has arrived. Parsed HTTP reply is passed as
`struct http_message` through the handler's `void *ev_data` pointer.
- MG_EV_HTTP_CHUNK: HTTP chunked-encoding chunk has arrived.
Parsed HTTP reply is passed as `struct http_message` through the
handler's `void *ev_data` pointer. `http_message::body` would contain
incomplete, reassembled HTTP body.
It will grow with every new chunk arrived, and
potentially can consume a lot of memory. An event handler may process
the body as chunks are coming, and signal Mongoose to delete processed
body by setting `MG_F_DELETE_CHUNK` in `mg_connection::flags`. When
the last zero chunk is received,
Mongoose sends `MG_EV_HTTP_REPLY` event with
full reassembled body (if handler did not signal to delete chunks) or
with empty body (if handler did signal to delete chunks).
- MG_EV_WEBSOCKET_HANDSHAKE_REQUEST: server has received websocket handshake
request. `ev_data` contains parsed HTTP request.
- MG_EV_WEBSOCKET_HANDSHAKE_DONE: server has completed Websocket handshake.
`ev_data` is `NULL`.
- MG_EV_WEBSOCKET_FRAME: new websocket frame has arrived. `ev_data` is
`struct websocket_message *`
- MG_EV_HTTP_PART_BEGIN: new part of multipart message is started,
extra parameters are passed in mg_http_multipart_part
- MG_EV_HTTP_PART_DATA: new portion of data from multiparted message
no additional headers are available, only data and data size
- MG_EV_HTTP_PART_END: final boundary received, analogue to maybe used to
find the end of packet
Note: Mongoose should be compiled with MG_ENABLE_HTTP_STREAMING_MULTIPART
to enable MG_EV_HTTP_MULTIPART_REQUEST, MG_EV_HTTP_REQUEST_END,
MG_EV_HTTP_REQUEST_CANCEL, MG_EV_HTTP_PART_BEGIN, MG_EV_HTTP_PART_DATA,
MG_EV_HTTP_PART_END constants
---
title: "mg_url_decode()"
decl_name: "mg_url_decode"
symbol_kind: "func"
signature: |
int mg_url_decode(const char *src, int src_len, char *dst, int dst_len,
int is_form_url_encoded);
---
Decode URL-encoded string.
Source string is specified by (`src`, `src_len`), and destination is
(`dst`, `dst_len`). If `is_form_url_encoded` is non-zero, then
`+` character is decoded as a blank space character. This function
guarantees to `\0`-terminate the destination. If destination is too small,
then source string is partially decoded and `-1` is returned. Otherwise,
a length of decoded string is returned, not counting final `\0`.
---
title: "struct http_message"
decl_name: "struct http_message"
symbol_kind: "struct"
signature: |
struct http_message {
struct mg_str message; /* Whole message: request line + headers + body */
/* HTTP Request line (or HTTP response line) */
struct mg_str method; /* "GET" */
struct mg_str uri; /* "/my_file.html" */
struct mg_str proto; /* "HTTP/1.1" -- for both request and response */
/* For responses, code and response status message are set */
int resp_code;
struct mg_str resp_status_msg;
/*
* Query-string part of the URI. For example, for HTTP request
* GET /foo/bar?param1=val1&param2=val2
* | uri | query_string |
*
* Note that question mark character doesn't belong neither to the uri,
* nor to the query_string
*/
struct mg_str query_string;
/* Headers */
struct mg_str header_names[MG_MAX_HTTP_HEADERS];
struct mg_str header_values[MG_MAX_HTTP_HEADERS];
/* Message body */
struct mg_str body; /* Zero-length for requests with no body */
};
---
HTTP message
---
title: "struct mg_http_multipart_part"
decl_name: "struct mg_http_multipart_part"
symbol_kind: "struct"
signature: |
struct mg_http_multipart_part {
const char *file_name;
const char *var_name;
struct mg_str data;
int status; /* <0 on error */
void *user_data;
};
---
HTTP multipart part
---
title: "struct mg_serve_http_opts"
decl_name: "struct mg_serve_http_opts"
symbol_kind: "struct"
signature: |
struct mg_serve_http_opts {
/* Path to web root directory */
const char *document_root;
/* List of index files. Default is "" */
const char *index_files;
/*
* Leave as NULL to disable authentication.
* To enable directory protection with authentication, set this to ".htpasswd"
* Then, creating ".htpasswd" file in any directory automatically protects
* it with digest authentication.
* Use `mongoose` web server binary, or `htdigest` Apache utility to
* create/manipulate passwords file.
* Make sure `auth_domain` is set to a valid domain name.
*/
const char *per_directory_auth_file;
/* Authorization domain (domain name of this web server) */
const char *auth_domain;
/*
* Leave as NULL to disable authentication.
* Normally, only selected directories in the document root are protected.
* If absolutely every access to the web server needs to be authenticated,
* regardless of the URI, set this option to the path to the passwords file.
* Format of that file is the same as ".htpasswd" file. Make sure that file
* is located outside document root to prevent people fetching it.
*/
const char *global_auth_file;
/* Set to "no" to disable directory listing. Enabled by default. */
const char *enable_directory_listing;
/* SSI files pattern. If not set, "**.shtml$|**.shtm$" is used. */
const char *ssi_pattern;
/* IP ACL. By default, NULL, meaning all IPs are allowed to connect */
const char *ip_acl;
/* URL rewrites.
*
* Comma-separated list of `uri_pattern=file_or_directory_path` rewrites.
* When HTTP request is received, Mongoose constructs a file name from the
* requested URI by combining `document_root` and the URI. However, if the
* rewrite option is used and `uri_pattern` matches requested URI, then
* `document_root` is ignored. Instead, `file_or_directory_path` is used,
* which should be a full path name or a path relative to the web server's
* current working directory. Note that `uri_pattern`, as all Mongoose
* patterns, is a prefix pattern.
*
* If uri_pattern starts with `@` symbol, then Mongoose compares it with the
* HOST header of the request. If they are equal, Mongoose sets document root
* to `file_or_directory_path`, implementing virtual hosts support.
* Example: `@foo.com=/document/root/for/foo.com`
*
* If `uri_pattern` starts with `%` symbol, then Mongoose compares it with
* the listening port. If they match, then Mongoose issues a 301 redirect.
* For example, to redirect all HTTP requests to the
* HTTPS port, do `%80=https://my.site.com`. Note that the request URI is
* automatically appended to the redirect location.
*/
const char *url_rewrites;
/* DAV document root. If NULL, DAV requests are going to fail. */
const char *dav_document_root;
/*
* DAV passwords file. If NULL, DAV requests are going to fail.
* If passwords file is set to "-", then DAV auth is disabled.
*/
const char *dav_auth_file;
/* Glob pattern for the files to hide. */
const char *hidden_file_pattern;
/* Set to non-NULL to enable CGI, e.g. **.cgi$|**.php$" */
const char *cgi_file_pattern;
/* If not NULL, ignore CGI script hashbang and use this interpreter */
const char *cgi_interpreter;
/*
* Comma-separated list of Content-Type overrides for path suffixes, e.g.
* ".txt=text/plain; charset=utf-8,.c=text/plain"
*/
const char *custom_mime_types;
/*
* Extra HTTP headers to add to each server response.
* Example: to enable CORS, set this to "Access-Control-Allow-Origin: *".
*/
const char *extra_headers;
};
---
This structure defines how `mg_serve_http()` works.
Best practice is to set only required settings, and leave the rest as NULL.
---
title: "struct websocket_message"
decl_name: "struct websocket_message"
symbol_kind: "struct"
signature: |
struct websocket_message {
unsigned char *data;
size_t size;
unsigned char flags;
};
---
WebSocket message
{
"items": [
{
"type": "section",
"name": "mbuf.h"
},
{
"type": "section",
"name": "net.h"
},
{
"type": "section",
"name": "http.h"
},
{
"type": "section",
"name": "json-rpc.h"
},
{
"type": "section",
"name": "dns.h"
},
{
"type": "section",
"name": "dns-server.h"
},
{
"type": "section",
"name": "mqtt.h"
},
{
"type": "section",
"name": "mqtt-broker.h"
},
{
"type": "section",
"name": "coap.h"
},
{
"type": "section",
"name": "util.h"
}
]
}
---
title: "JSON-RPC"
symbol_kind: "intro"
decl_name: "json-rpc.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_rpc_parse_reply.md"
},
{
"type": "markdown",
"name": "mg_rpc_create_request.md"
},
{
"type": "markdown",
"name": "mg_rpc_create_reply.md"
},
{
"type": "markdown",
"name": "mg_rpc_create_error.md"
},
{
"type": "markdown",
"name": "mg_rpc_create_std_error.md"
},
{
"type": "markdown",
"name": "mg_rpc_dispatch.md"
},
{
"type": "markdown",
"name": "struct_mg_rpc_request.md"
},
{
"type": "markdown",
"name": "struct_mg_rpc_reply.md"
},
{
"type": "markdown",
"name": "struct_mg_rpc_error.md"
}
]
}
---
title: "mg_rpc_create_error()"
decl_name: "mg_rpc_create_error"
symbol_kind: "func"
signature: |
int mg_rpc_create_error(char *buf, int len, struct mg_rpc_request *req,
int code, const char *message, const char *fmt, ...);
---
Create JSON-RPC error reply in a given buffer.
Return length of the error, which
can be larger then `len` that indicates an overflow.
`fmt` format string should conform to `json_emit()` API,
see https://github.com/cesanta/frozen
---
title: "mg_rpc_create_reply()"
decl_name: "mg_rpc_create_reply"
symbol_kind: "func"
signature: |
int mg_rpc_create_reply(char *buf, int len, const struct mg_rpc_request *req,
const char *result_fmt, ...);
---
Create JSON-RPC reply in a given buffer.
Return length of the reply, which
can be larger then `len` that indicates an overflow.
`result_fmt` format string should conform to `json_emit()` API,
see https://github.com/cesanta/frozen
---
title: "mg_rpc_create_request()"
decl_name: "mg_rpc_create_request"
symbol_kind: "func"
signature: |
int mg_rpc_create_request(char *buf, int len, const char *method,
const char *id, const char *params_fmt, ...);
---
Create JSON-RPC request in a given buffer.
Return length of the request, which
can be larger then `len` that indicates an overflow.
`params_fmt` format string should conform to `json_emit()` API,
see https://github.com/cesanta/frozen
---
title: "mg_rpc_create_std_error()"
decl_name: "mg_rpc_create_std_error"
symbol_kind: "func"
signature: |
int mg_rpc_create_std_error(char *buf, int len, struct mg_rpc_request *req,
int code);
---
Create JSON-RPC error in a given buffer.
Return length of the error, which
can be larger then `len` that indicates an overflow. See
JSON_RPC_*_ERROR definitions for standard error values:
- `#define JSON_RPC_PARSE_ERROR (-32700)`
- `#define JSON_RPC_INVALID_REQUEST_ERROR (-32600)`
- `#define JSON_RPC_METHOD_NOT_FOUND_ERROR (-32601)`
- `#define JSON_RPC_INVALID_PARAMS_ERROR (-32602)`
- `#define JSON_RPC_INTERNAL_ERROR (-32603)`
- `#define JSON_RPC_SERVER_ERROR (-32000)`
---
title: "mg_rpc_dispatch()"
decl_name: "mg_rpc_dispatch"
symbol_kind: "func"
signature: |
int mg_rpc_dispatch(const char *buf, int, char *dst, int dst_len,
const char **methods, mg_rpc_handler_t *handlers);
---
Dispatches a JSON-RPC request.
Parses JSON-RPC request contained in `buf`, `len`.
Then, dispatches the request to the correct handler method.
Valid method names should be specified in NULL
terminated array `methods`, and corresponding handlers in `handlers`.
Result is put in `dst`, `dst_len`. Return: length of the result, which
can be larger then `dst_len` that indicates an overflow.
Overflown bytes are not written to the buffer.
If method is not found, an error is automatically generated.
---
title: "mg_rpc_parse_reply()"
decl_name: "mg_rpc_parse_reply"
symbol_kind: "func"
signature: |
int mg_rpc_parse_reply(const char *buf, int len, struct json_token *toks,
int max_toks, struct mg_rpc_reply *,
struct mg_rpc_error *);
---
Parse JSON-RPC reply contained in `buf`, `len` into JSON tokens array
`toks`, `max_toks`. If buffer contains valid reply, `reply` structure is
populated. The result of RPC call is located in `reply.result`. On error,
`error` structure is populated. Returns: the result of calling
`parse_json(buf, len, toks, max_toks)`:
On success, an offset inside `json_string` is returned
where parsing has finished. On failure, a negative number is
returned, one of:
- `#define JSON_STRING_INVALID -1`
- `#define JSON_STRING_INCOMPLETE -2`
- `#define JSON_TOKEN_ARRAY_TOO_SMALL -3`
---
title: "struct mg_rpc_error"
decl_name: "struct mg_rpc_error"
symbol_kind: "struct"
signature: |
struct mg_rpc_error {
struct json_token *message; /* Whole RPC message */
struct json_token *id; /* Message ID */
struct json_token *error_code; /* error.code */
struct json_token *error_message; /* error.message */
struct json_token *error_data; /* error.data, can be NULL */
};
---
JSON-RPC error
---
title: "struct mg_rpc_reply"
decl_name: "struct mg_rpc_reply"
symbol_kind: "struct"
signature: |
struct mg_rpc_reply {
struct json_token *message; /* Whole RPC message */
struct json_token *id; /* Message ID */
struct json_token *result; /* Remote call result */
};
---
JSON-RPC response
---
title: "struct mg_rpc_request"
decl_name: "struct mg_rpc_request"
symbol_kind: "struct"
signature: |
struct mg_rpc_request {
struct json_token *message; /* Whole RPC message */
struct json_token *id; /* Message ID */
struct json_token *method; /* Method name */
struct json_token *params; /* Method params */
};
---
JSON-RPC request
---
title: "Memory Buffers"
symbol_kind: "intro"
decl_name: "mbuf.h"
---
Mbufs are mutable/growing memory buffers, like C++ strings.
Mbuf can append data to the end of a buffer, or insert data into arbitrary
position in the middle of a buffer. The buffer grows automatically when
needed.
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mbuf_init.md"
},
{
"type": "markdown",
"name": "mbuf_free.md"
},
{
"type": "markdown",
"name": "mbuf_append.md"
},
{
"type": "markdown",
"name": "mbuf_insert.md"
},
{
"type": "markdown",
"name": "mbuf_remove.md"
},
{
"type": "markdown",
"name": "mbuf_resize.md"
},
{
"type": "markdown",
"name": "mbuf_trim.md"
},
{
"type": "markdown",
"name": "struct_mbuf.md"
}
]
}
---
title: "mbuf_append()"
decl_name: "mbuf_append"
symbol_kind: "func"
signature: |
size_t mbuf_append(struct mbuf *, const void *data, size_t data_size);
---
Appends data to the Mbuf.
Return the number of bytes appended, or 0 if out of memory.
---
title: "mbuf_free()"
decl_name: "mbuf_free"
symbol_kind: "func"
signature: |
void mbuf_free(struct mbuf *);
---
Free the space allocated for the mbuffer and resets the mbuf structure.
---
title: "mbuf_init()"
decl_name: "mbuf_init"
symbol_kind: "func"
signature: |
void mbuf_init(struct mbuf *, size_t initial_capacity);
---
Initialize an Mbuf.
`initial_capacity` specifies the initial capacity of the mbuf.
---
title: "mbuf_insert()"
decl_name: "mbuf_insert"
symbol_kind: "func"
signature: |
size_t mbuf_insert(struct mbuf *, size_t, const void *, size_t);
---
Insert data at a specified offset in the Mbuf.
Existing data will be shifted forwards and the buffer will
be grown if necessary.
Return the number of bytes inserted.
---
title: "mbuf_remove()"
decl_name: "mbuf_remove"
symbol_kind: "func"
signature: |
void mbuf_remove(struct mbuf *, size_t data_size);
---
Remove `data_size` bytes from the beginning of the buffer.
---
title: "mbuf_resize()"
decl_name: "mbuf_resize"
symbol_kind: "func"
signature: |
void mbuf_resize(struct mbuf *, size_t new_size);
---
Resize an Mbuf.
If `new_size` is smaller than buffer's `len`, the
resize is not performed.
---
title: "mbuf_trim()"
decl_name: "mbuf_trim"
symbol_kind: "func"
signature: |
void mbuf_trim(struct mbuf *);
---
Shrink an Mbuf by resizing its `size` to `len`.
---
title: "struct mbuf"
decl_name: "struct mbuf"
symbol_kind: "struct"
signature: |
struct mbuf {
char *buf; /* Buffer pointer */
size_t len; /* Data length. Data is located between offset 0 and len. */
size_t size; /* Buffer size allocated by realloc(1). Must be >= len */
};
---
Memory buffer descriptor
---
title: "MQTT Broker"
symbol_kind: "intro"
decl_name: "mqtt-broker.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_mqtt_broker_init.md"
},
{
"type": "markdown",
"name": "mg_mqtt_broker.md"
},
{
"type": "markdown",
"name": "mg_mqtt_next.md"
},
{
"type": "markdown",
"name": "struct_mg_mqtt_session.md"
},
{
"type": "markdown",
"name": "struct_mg_mqtt_broker.md"
}
]
}
---
title: "mg_mqtt_broker()"
decl_name: "mg_mqtt_broker"
symbol_kind: "func"
signature: |
void mg_mqtt_broker(struct mg_connection *brk, int ev, void *data);
---
Process a MQTT broker message.
Listening connection expects a pointer to an initialized `mg_mqtt_broker`
structure in the `user_data` field.
Basic usage:
```c
mg_mqtt_broker_init(&brk, NULL);
if ((nc = mg_bind(&mgr, address, mg_mqtt_broker)) == NULL) {
// fail;
}
nc->user_data = &brk;
```
New incoming connections will receive a `mg_mqtt_session` structure
in the connection `user_data`. The original `user_data` will be stored
in the `user_data` field of the session structure. This allows the user
handler to store user data before `mg_mqtt_broker` creates the session.
Since only the MG_EV_ACCEPT message is processed by the listening socket,
for most events the `user_data` will thus point to a `mg_mqtt_session`.
---
title: "mg_mqtt_broker_init()"
decl_name: "mg_mqtt_broker_init"
symbol_kind: "func"
signature: |
void mg_mqtt_broker_init(struct mg_mqtt_broker *brk, void *user_data);
---
Initialize a MQTT broker.
---
title: "mg_mqtt_next()"
decl_name: "mg_mqtt_next"
symbol_kind: "func"
signature: |
struct mg_mqtt_session *mg_mqtt_next(struct mg_mqtt_broker *brk,
struct mg_mqtt_session *s);
---
Iterate over all mqtt sessions connections. Example:
```c
struct mg_mqtt_session *s;
for (s = mg_mqtt_next(brk, NULL); s != NULL; s = mg_mqtt_next(brk, s)) {
// Do something
}
```
---
title: "struct mg_mqtt_broker"
decl_name: "struct mg_mqtt_broker"
symbol_kind: "struct"
signature: |
struct mg_mqtt_broker {
struct mg_mqtt_session *sessions; /* Session list */
void *user_data; /* User data */
};
---
MQTT broker.
---
title: "struct mg_mqtt_session"
decl_name: "struct mg_mqtt_session"
symbol_kind: "struct"
signature: |
struct mg_mqtt_session {
struct mg_mqtt_broker *brk; /* Broker */
struct mg_mqtt_session *next, *prev; /* mg_mqtt_broker::sessions linkage */
struct mg_connection *nc; /* Connection with the client */
size_t num_subscriptions; /* Size of `subscriptions` array */
struct mg_mqtt_topic_expression *subscriptions;
void *user_data; /* User data */
};
---
MQTT session (Broker side).
---
title: "MQTT"
symbol_kind: "intro"
decl_name: "mqtt.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_set_protocol_mqtt.md"
},
{
"type": "markdown",
"name": "mg_send_mqtt_handshake.md"
},
{
"type": "markdown",
"name": "mg_send_mqtt_handshake_opt.md"
},
{
"type": "markdown",
"name": "mg_mqtt_publish.md"
},
{
"type": "markdown",
"name": "mg_mqtt_subscribe.md"
},
{
"type": "markdown",
"name": "mg_mqtt_unsubscribe.md"
},
{
"type": "markdown",
"name": "mg_mqtt_disconnect.md"
},
{
"type": "markdown",
"name": "mg_mqtt_connack.md"
},
{
"type": "markdown",
"name": "mg_mqtt_puback.md"
},
{
"type": "markdown",
"name": "mg_mqtt_pubrec.md"
},
{
"type": "markdown",
"name": "mg_mqtt_pubrel.md"
},
{
"type": "markdown",
"name": "mg_mqtt_pubcomp.md"
},
{
"type": "markdown",
"name": "mg_mqtt_suback.md"
},
{
"type": "markdown",
"name": "mg_mqtt_unsuback.md"
},
{
"type": "markdown",
"name": "mg_mqtt_ping.md"
},
{
"type": "markdown",
"name": "mg_mqtt_pong.md"
},
{
"type": "markdown",
"name": "mg_mqtt_next_subscribe_topic.md"
},
{
"type": "markdown",
"name": "struct_mg_mqtt_topic_expression.md"
}
]
}
---
title: "mg_mqtt_connack()"
decl_name: "mg_mqtt_connack"
symbol_kind: "func"
signature: |
void mg_mqtt_connack(struct mg_connection *nc, uint8_t return_code);
---
Send a CONNACK command with a given `return_code`.
---
title: "mg_mqtt_disconnect()"
decl_name: "mg_mqtt_disconnect"
symbol_kind: "func"
signature: |
void mg_mqtt_disconnect(struct mg_connection *nc);
---
Send a DISCONNECT command.
---
title: "mg_mqtt_next_subscribe_topic()"
decl_name: "mg_mqtt_next_subscribe_topic"
symbol_kind: "func"
signature: |
int mg_mqtt_next_subscribe_topic(struct mg_mqtt_message *msg,
struct mg_str *topic, uint8_t *qos, int pos);
---
Extract the next topic expression from a SUBSCRIBE command payload.
Topic expression name will point to a string in the payload buffer.
Return the pos of the next topic expression or -1 when the list
of topics is exhausted.
---
title: "mg_mqtt_ping()"
decl_name: "mg_mqtt_ping"
symbol_kind: "func"
signature: |
void mg_mqtt_ping(struct mg_connection *nc);
---
Send a PINGREQ command.
---
title: "mg_mqtt_pong()"
decl_name: "mg_mqtt_pong"
symbol_kind: "func"
signature: |
void mg_mqtt_pong(struct mg_connection *nc);
---
Send a PINGRESP command.
---
title: "mg_mqtt_puback()"
decl_name: "mg_mqtt_puback"
symbol_kind: "func"
signature: |
void mg_mqtt_puback(struct mg_connection *nc, uint16_t message_id);
---
Send a PUBACK command with a given `message_id`.
---
title: "mg_mqtt_pubcomp()"
decl_name: "mg_mqtt_pubcomp"
symbol_kind: "func"
signature: |
void mg_mqtt_pubcomp(struct mg_connection *nc, uint16_t message_id);
---
Send a PUBCOMP command with a given `message_id`.
---
title: "mg_mqtt_publish()"
decl_name: "mg_mqtt_publish"
symbol_kind: "func"
signature: |
void mg_mqtt_publish(struct mg_connection *nc, const char *topic,
uint16_t message_id, int flags, const void *data,
size_t len);
---
Publish a message to a given topic.
---
title: "mg_mqtt_pubrec()"
decl_name: "mg_mqtt_pubrec"
symbol_kind: "func"
signature: |
void mg_mqtt_pubrec(struct mg_connection *nc, uint16_t message_id);
---
Send a PUBREC command with a given `message_id`.
---
title: "mg_mqtt_pubrel()"
decl_name: "mg_mqtt_pubrel"
symbol_kind: "func"
signature: |
void mg_mqtt_pubrel(struct mg_connection *nc, uint16_t message_id);
---
Send a PUBREL command with a given `message_id`.
---
title: "mg_mqtt_suback()"
decl_name: "mg_mqtt_suback"
symbol_kind: "func"
signature: |
void mg_mqtt_suback(struct mg_connection *nc, uint8_t *qoss, size_t qoss_len,
uint16_t message_id);
---
Send a SUBACK command with a given `message_id`
and a sequence of granted QoSs.
---
title: "mg_mqtt_subscribe()"
decl_name: "mg_mqtt_subscribe"
symbol_kind: "func"
signature: |
void mg_mqtt_subscribe(struct mg_connection *nc,
const struct mg_mqtt_topic_expression *topics,
size_t topics_len, uint16_t message_id);
---
Subscribe to a bunch of topics.
---
title: "mg_mqtt_unsuback()"
decl_name: "mg_mqtt_unsuback"
symbol_kind: "func"
signature: |
void mg_mqtt_unsuback(struct mg_connection *nc, uint16_t message_id);
---
Send a UNSUBACK command with a given `message_id`.
---
title: "mg_mqtt_unsubscribe()"
decl_name: "mg_mqtt_unsubscribe"
symbol_kind: "func"
signature: |
void mg_mqtt_unsubscribe(struct mg_connection *nc, char **topics,
size_t topics_len, uint16_t message_id);
---
Unsubscribe from a bunch of topics.
---
title: "mg_send_mqtt_handshake()"
decl_name: "mg_send_mqtt_handshake"
symbol_kind: "func"
signature: |
void mg_send_mqtt_handshake(struct mg_connection *nc, const char *client_id);
---
Send MQTT handshake.
---
title: "mg_send_mqtt_handshake_opt()"
decl_name: "mg_send_mqtt_handshake_opt"
symbol_kind: "func"
signature: |
void mg_send_mqtt_handshake_opt(struct mg_connection *nc, const char *client_id,
struct mg_send_mqtt_handshake_opts);
---
Send MQTT handshake with optional parameters.
---
title: "mg_set_protocol_mqtt()"
decl_name: "mg_set_protocol_mqtt"
symbol_kind: "func"
signature: |
void mg_set_protocol_mqtt(struct mg_connection *nc);
---
Attach built-in MQTT event handler to the given connection.
The user-defined event handler will receive following extra events:
- MG_EV_MQTT_CONNACK
- MG_EV_MQTT_PUBLISH
- MG_EV_MQTT_PUBACK
- MG_EV_MQTT_PUBREC
- MG_EV_MQTT_PUBREL
- MG_EV_MQTT_PUBCOMP
- MG_EV_MQTT_SUBACK
---
title: "struct mg_mqtt_topic_expression"
decl_name: "struct mg_mqtt_topic_expression"
symbol_kind: "struct"
signature: |
struct mg_mqtt_topic_expression {
const char *topic;
uint8_t qos;
};
---
puback
---
title: "Core: TCP/UDP/SSL"
symbol_kind: "intro"
decl_name: "net.h"
---
NOTE: Mongoose manager is single threaded. It does not protect
its data structures by mutexes, therefore all functions that are dealing
with particular event manager should be called from the same thread,
with exception of `mg_broadcast()` function. It is fine to have different
event managers handled by different threads.
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_mgr_init.md"
},
{
"type": "markdown",
"name": "mg_mgr_free.md"
},
{
"type": "markdown",
"name": "mg_mgr_poll.md"
},
{
"type": "markdown",
"name": "mg_broadcast.md"
},
{
"type": "markdown",
"name": "mg_next.md"
},
{
"type": "markdown",
"name": "mg_add_sock.md"
},
{
"type": "markdown",
"name": "mg_add_sock_opt.md"
},
{
"type": "markdown",
"name": "mg_bind.md"
},
{
"type": "markdown",
"name": "mg_bind_opt.md"
},
{
"type": "markdown",
"name": "mg_connect.md"
},
{
"type": "markdown",
"name": "mg_connect_opt.md"
},
{
"type": "markdown",
"name": "mg_set_ssl.md"
},
{
"type": "markdown",
"name": "mg_send.md"
},
{
"type": "markdown",
"name": "mg_printf.md"
},
{
"type": "markdown",
"name": "mg_vprintf.md"
},
{
"type": "markdown",
"name": "mg_socketpair.md"
},
{
"type": "markdown",
"name": "mg_check_ip_acl.md"
},
{
"type": "markdown",
"name": "mg_enable_multithreading.md"
},
{
"type": "markdown",
"name": "mg_enable_javascript.md"
},
{
"type": "markdown",
"name": "mg_set_timer.md"
},
{
"type": "markdown",
"name": "mg_time.md"
},
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"name": "mg_event_handler_t.md"
},
{
"type": "markdown",
"name": "struct_mg_str.md"
},
{
"type": "markdown",
"name": "struct_mg_mgr.md"
},
{
"type": "markdown",
"name": "struct_mg_connection.md"
},
{
"type": "markdown",
"name": "struct_mg_add_sock_opts.md"
},
{
"type": "markdown",
"name": "struct_mg_bind_opts.md"
},
{
"type": "markdown",
"name": "struct_mg_connect_opts.md"
}
]
}
---
title: "mg_add_sock()"
decl_name: "mg_add_sock"
symbol_kind: "func"
signature: |
struct mg_connection *mg_add_sock(struct mg_mgr *, sock_t, mg_event_handler_t);
---
Create a connection, associate it with the given socket and event handler,
and add it to the manager.
For more options see the `mg_add_sock_opt` variant.
---
title: "mg_add_sock_opt()"
decl_name: "mg_add_sock_opt"
symbol_kind: "func"
signature: |
struct mg_connection *mg_add_sock_opt(struct mg_mgr *, sock_t,
mg_event_handler_t,
struct mg_add_sock_opts);
---
Create a connection, associate it with the given socket and event handler,
and add to the manager.
See the `mg_add_sock_opts` structure for a description of the options.
---
title: "mg_bind()"
decl_name: "mg_bind"
symbol_kind: "func"
signature: |
struct mg_connection *mg_bind(struct mg_mgr *, const char *,
mg_event_handler_t);
---
Create listening connection.
See `mg_bind_opt` for full documentation.
---
title: "mg_bind_opt()"
decl_name: "mg_bind_opt"
symbol_kind: "func"
signature: |
struct mg_connection *mg_bind_opt(struct mg_mgr *mgr, const char *address,
mg_event_handler_t handler,
struct mg_bind_opts opts);
---
Create listening connection.
`address` parameter tells which address to bind to. It's format is the same
as for the `mg_connect()` call, where `HOST` part is optional. `address`
can be just a port number, e.g. `:8000`. To bind to a specific interface,
an IP address can be specified, e.g. `1.2.3.4:8000`. By default, a TCP
connection is created. To create UDP connection, prepend `udp://` prefix,
e.g. `udp://:8000`. To summarize, `address` paramer has following format:
`[PROTO://][IP_ADDRESS]:PORT`, where `PROTO` could be `tcp` or `udp`.
See the `mg_bind_opts` structure for a description of the optional
parameters.
Return a new listening connection, or `NULL` on error.
NOTE: Connection remains owned by the manager, do not free().
---
title: "mg_broadcast()"
decl_name: "mg_broadcast"
symbol_kind: "func"
signature: |
void mg_broadcast(struct mg_mgr *, mg_event_handler_t func, void *, size_t);
---
Pass a message of a given length to all connections.
Must be called from a thread that does NOT call `mg_mgr_poll()`.
Note that `mg_broadcast()` is the only function
that can be, and must be, called from a different (non-IO) thread.
`func` callback function will be called by the IO thread for each
connection. When called, event would be `MG_EV_POLL`, and message will
be passed as `ev_data` pointer. Maximum message size is capped
by `MG_CTL_MSG_MESSAGE_SIZE` which is set to 8192 bytes.
---
title: "mg_check_ip_acl()"
decl_name: "mg_check_ip_acl"
symbol_kind: "func"
signature: |
int mg_check_ip_acl(const char *acl, uint32_t remote_ip);
---
Verify given IP address against the ACL.
`remote_ip` - an IPv4 address to check, in host byte order
`acl` - a comma separated list of IP subnets: `x.x.x.x/x` or `x.x.x.x`.
Each subnet is
prepended by either a - or a + sign. A plus sign means allow, where a
minus sign means deny. If a subnet mask is omitted, such as `-1.2.3.4`,
this means to deny only that single IP address.
Subnet masks may vary from 0 to 32, inclusive. The default setting
is to allow all accesses. On each request the full list is traversed,
and the last match wins. Example:
`-0.0.0.0/0,+192.168/16` - deny all acccesses, only allow 192.168/16 subnet
To learn more about subnet masks, see the
link:https://en.wikipedia.org/wiki/Subnetwork[Wikipedia page on Subnetwork]
Return -1 if ACL is malformed, 0 if address is disallowed, 1 if allowed.
---
title: "mg_connect()"
decl_name: "mg_connect"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *address,
mg_event_handler_t handler);
---
Connect to a remote host.
See `mg_connect_opt()` for full documentation.
---
title: "mg_connect_opt()"
decl_name: "mg_connect_opt"
symbol_kind: "func"
signature: |
struct mg_connection *mg_connect_opt(struct mg_mgr *mgr, const char *address,
mg_event_handler_t handler,
struct mg_connect_opts opts);
---
Connect to a remote host.
`address` format is `[PROTO://]HOST:PORT`. `PROTO` could be `tcp` or `udp`.
`HOST` could be an IP address,
IPv6 address (if Mongoose is compiled with `-DMG_ENABLE_IPV6`), or a host
name. If `HOST` is a name, Mongoose will resolve it asynchronously. Examples
of valid addresses: `google.com:80`, `udp://1.2.3.4:53`, `10.0.0.1:443`,
`[::1]:80`
See the `mg_connect_opts` structure for a description of the optional
parameters.
Returns a new outbound connection, or `NULL` on error.
NOTE: Connection remains owned by the manager, do not free().
NOTE: To enable IPv6 addresses, `-DMG_ENABLE_IPV6` should be specified
in the compilation flags.
NOTE: New connection will receive `MG_EV_CONNECT` as it's first event
which will report connect success status.
If asynchronous resolution fail, or `connect()` syscall fail for whatever
reason (e.g. with `ECONNREFUSED` or `ENETUNREACH`), then `MG_EV_CONNECT`
event report failure. Code example below:
```c
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
int connect_status;
switch (ev) {
case MG_EV_CONNECT:
connect_status = * (int *) ev_data;
if (connect_status == 0) {
// Success
} else {
// Error
printf("connect() error: %s\n", strerror(connect_status));
}
break;
...
}
}
...
mg_connect(mgr, "my_site.com:80", ev_handler);
```
---
title: "mg_enable_javascript()"
decl_name: "mg_enable_javascript"
symbol_kind: "func"
signature: |
enum v7_err mg_enable_javascript(struct mg_mgr *m, struct v7 *v7,
const char *init_js_file_name);
---
Enable server-side JavaScript scripting.
Requires `-DMG_ENABLE_JAVASCRIPT` compilation flag, and V7 engine sources.
v7 instance must not be destroyed during manager's lifetime.
Return V7 error.
---
title: "mg_enable_multithreading()"
decl_name: "mg_enable_multithreading"
symbol_kind: "func"
signature: |
void mg_enable_multithreading(struct mg_connection *nc);
---
Enable multi-threaded handling for the given listening connection `nc`.
For each accepted connection, Mongoose will create a separate thread
and run event handler in that thread. Thus, if an event hanler is doing
a blocking call or some long computation, that will not slow down
other connections.
---
title: "mg_event_handler_t"
decl_name: "mg_event_handler_t"
symbol_kind: "typedef"
signature: |
typedef void (*mg_event_handler_t)(struct mg_connection *, int ev, void *);
---
Callback function (event handler) prototype, must be defined by user.
Mongoose calls event handler, passing events defined below.
---
title: "mg_mgr_free()"
decl_name: "mg_mgr_free"
symbol_kind: "func"
signature: |
void mg_mgr_free(struct mg_mgr *);
---
De-initializes Mongoose manager.
Close and deallocate all active connections.
---
title: "mg_mgr_init()"
decl_name: "mg_mgr_init"
symbol_kind: "func"
signature: |
void mg_mgr_init(struct mg_mgr *mgr, void *user_data);
---
Initialize Mongoose manager. Side effect: ignores SIGPIPE signal.
`mgr->user_data` field will be initialized with `user_data` parameter.
That is an arbitrary pointer, where user code can associate some data
with the particular Mongoose manager. For example, a C++ wrapper class
could be written, in which case `user_data` can hold a pointer to the
class instance.
---
title: "mg_mgr_poll()"
decl_name: "mg_mgr_poll"
symbol_kind: "func"
signature: |
time_t mg_mgr_poll(struct mg_mgr *, int milli);
---
This function performs the actual IO, and must be called in a loop
(an event loop). Returns the current timestamp.
`milli` is the maximum number of milliseconds to sleep.
`mg_mgr_poll()` checks all connection for IO readiness. If at least one
of the connections is IO-ready, `mg_mgr_poll()` triggers respective
event handlers and returns.
---
title: "mg_next()"
decl_name: "mg_next"
symbol_kind: "func"
signature: |
struct mg_connection *mg_next(struct mg_mgr *, struct mg_connection *);
---
Iterate over all active connections.
Returns next connection from the list
of active connections, or `NULL` if there is no more connections. Below
is the iteration idiom:
```c
for (c = mg_next(srv, NULL); c != NULL; c = mg_next(srv, c)) {
// Do something with connection `c`
}
```
---
title: "mg_printf()"
decl_name: "mg_printf"
symbol_kind: "func"
signature: |
int mg_printf(struct mg_connection *, const char *fmt, ...);
---
Send `printf`-style formatted data to the connection.
See `mg_send` for more details on send semantics.
---
title: "mg_send()"
decl_name: "mg_send"
symbol_kind: "func"
signature: |
void mg_send(struct mg_connection *, const void *buf, int len);
---
Send data to the connection.
Note that sending functions do not actually push data to the socket.
They just append data to the output buffer. MG_EV_SEND will be delivered when
the data has actually been pushed out.
---
title: "mg_set_ssl()"
decl_name: "mg_set_ssl"
symbol_kind: "func"
signature: |
const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
const char *ca_cert);
---
Enable SSL for a given connection.
`cert` is a server certificate file name for a listening connection,
or a client certificate file name for an outgoing connection.
Certificate files must be in PEM format. Server certificate file
must contain a certificate, concatenated with a private key, optionally
concatenated with parameters.
`ca_cert` is a CA certificate, or NULL if peer verification is not
required.
Return: NULL on success, or error message on error.
---
title: "mg_set_timer()"
decl_name: "mg_set_timer"
symbol_kind: "func"
signature: |
double mg_set_timer(struct mg_connection *c, double timestamp);
---
Schedule MG_EV_TIMER event to be delivered at `timestamp` time.
`timestamp` is a UNIX time (a number of seconds since Epoch). It is
`double` instead of `time_t` to allow for sub-second precision.
Return the old timer value.
Example: set connect timeout to 1.5 seconds:
```
c = mg_connect(&mgr, "cesanta.com", ev_handler);
mg_set_timer(c, mg_time() + 1.5);
...
void ev_handler(struct mg_connection *c, int ev, void *ev_data) {
switch (ev) {
case MG_EV_CONNECT:
mg_set_timer(c, 0); // Clear connect timer
break;
case MG_EV_TIMER:
log("Connect timeout");
c->flags |= MG_F_CLOSE_IMMEDIATELY;
break;
```
---
title: "mg_socketpair()"
decl_name: "mg_socketpair"
symbol_kind: "func"
signature: |
int mg_socketpair(sock_t[2], int sock_type);
---
Create a socket pair.
`sock_type` can be either `SOCK_STREAM` or `SOCK_DGRAM`.
Return 0 on failure, 1 on success.
---
title: "mg_time()"
decl_name: "mg_time"
symbol_kind: "func"
signature: |
double mg_time();
---
A sub-second precision version of time().
---
title: "mg_vprintf()"
decl_name: "mg_vprintf"
symbol_kind: "func"
signature: |
int mg_vprintf(struct mg_connection *, const char *fmt, va_list ap);
---
Same as `mg_printf()`, but takes `va_list ap` as an argument.
---
title: "struct mg_add_sock_opts"
decl_name: "struct mg_add_sock_opts"
symbol_kind: "struct"
signature: |
struct mg_add_sock_opts {
void *user_data; /* Initial value for connection's user_data */
unsigned int flags; /* Initial connection flags */
const char **error_string; /* Placeholder for the error string */
};
---
Optional parameters to `mg_add_sock_opt()`.
`flags` is an initial `struct mg_connection::flags` bitmask to set,
see `MG_F_*` flags definitions.
---
title: "struct mg_bind_opts"
decl_name: "struct mg_bind_opts"
symbol_kind: "struct"
signature: |
struct mg_bind_opts {
void *user_data; /* Initial value for connection's user_data */
unsigned int flags; /* Extra connection flags */
const char **error_string; /* Placeholder for the error string */
#ifdef MG_ENABLE_SSL
/* SSL settings. */
const char *ssl_cert; /* Server certificate to present to clients */
const char *ssl_ca_cert; /* Verify client certificates with this CA bundle */
#endif
};
---
Optional parameters to `mg_bind_opt()`.
`flags` is an initial `struct mg_connection::flags` bitmask to set,
see `MG_F_*` flags definitions.
---
title: "struct mg_connect_opts"
decl_name: "struct mg_connect_opts"
symbol_kind: "struct"
signature: |
struct mg_connect_opts {
void *user_data; /* Initial value for connection's user_data */
unsigned int flags; /* Extra connection flags */
const char **error_string; /* Placeholder for the error string */
#ifdef MG_ENABLE_SSL
/* SSL settings. */
const char *ssl_cert; /* Client certificate to present to the server */
const char *ssl_ca_cert; /* Verify server certificate using this CA bundle */
/*
* Server name verification. If ssl_ca_cert is set and the certificate has
* passed verification, its subject will be verified against this string.
* By default (if ssl_server_name is NULL) hostname part of the address will
* be used. Wildcard matching is supported. A special value of "*" disables
* name verification.
*/
const char *ssl_server_name;
#endif
};
---
Optional parameters to `mg_connect_opt()`
---
title: "struct mg_connection"
decl_name: "struct mg_connection"
symbol_kind: "struct"
signature: |
struct mg_connection {
struct mg_connection *next, *prev; /* mg_mgr::active_connections linkage */
struct mg_connection *listener; /* Set only for accept()-ed connections */
struct mg_mgr *mgr; /* Pointer to containing manager */
sock_t sock; /* Socket to the remote peer */
int err;
union socket_address sa; /* Remote peer address */
size_t recv_mbuf_limit; /* Max size of recv buffer */
struct mbuf recv_mbuf; /* Received data */
struct mbuf send_mbuf; /* Data scheduled for sending */
SSL *ssl;
SSL_CTX *ssl_ctx;
time_t last_io_time; /* Timestamp of the last socket IO */
double ev_timer_time; /* Timestamp of the future MG_EV_TIMER */
mg_event_handler_t proto_handler; /* Protocol-specific event handler */
void *proto_data; /* Protocol-specific data */
void (*proto_data_destructor)(void *proto_data);
mg_event_handler_t handler; /* Event handler function */
void *user_data; /* User-specific data */
union {
void *v;
/*
* the C standard is fussy about fitting function pointers into
* void pointers, since some archs might have fat pointers for functions.
*/
mg_event_handler_t f;
} priv_1; /* Used by mg_enable_multithreading() */
void *priv_2; /* Used by mg_enable_multithreading() */
void *mgr_data; /* Implementation-specific event manager's data. */
unsigned long flags;
/* Flags set by Mongoose */
#define MG_F_LISTENING (1 << 0) /* This connection is listening */
#define MG_F_UDP (1 << 1) /* This connection is UDP */
#define MG_F_RESOLVING (1 << 2) /* Waiting for async resolver */
#define MG_F_CONNECTING (1 << 3) /* connect() call in progress */
#define MG_F_SSL_HANDSHAKE_DONE (1 << 4) /* SSL specific */
#define MG_F_WANT_READ (1 << 5) /* SSL specific */
#define MG_F_WANT_WRITE (1 << 6) /* SSL specific */
#define MG_F_IS_WEBSOCKET (1 << 7) /* Websocket specific */
/* Flags that are settable by user */
#define MG_F_SEND_AND_CLOSE (1 << 10) /* Push remaining data and close */
#define MG_F_CLOSE_IMMEDIATELY (1 << 11) /* Disconnect */
#define MG_F_WEBSOCKET_NO_DEFRAG (1 << 12) /* Websocket specific */
#define MG_F_DELETE_CHUNK (1 << 13) /* HTTP specific */
#define MG_F_USER_1 (1 << 20) /* Flags left for application */
#define MG_F_USER_2 (1 << 21)
#define MG_F_USER_3 (1 << 22)
#define MG_F_USER_4 (1 << 23)
#define MG_F_USER_5 (1 << 24)
#define MG_F_USER_6 (1 << 25)
};
---
Mongoose connection.
---
title: "struct mg_mgr"
decl_name: "struct mg_mgr"
symbol_kind: "struct"
signature: |
struct mg_mgr {
struct mg_connection *active_connections;
const char *hexdump_file; /* Debug hexdump file path */
#ifndef MG_DISABLE_SOCKETPAIR
sock_t ctl[2]; /* Socketpair for mg_wakeup() */
#endif
void *user_data; /* User data */
void *mgr_data; /* Implementation-specific event manager's data. */
#ifdef MG_ENABLE_JAVASCRIPT
struct v7 *v7;
#endif
};
---
Mongoose event manager.
---
title: "struct mg_str"
decl_name: "struct mg_str"
symbol_kind: "struct"
signature: |
struct mg_str {
const char *p; /* Memory chunk pointer */
size_t len; /* Memory chunk length */
};
---
Describes chunk of memory
---
title: "MG_MK_STR()"
decl_name: "MG_MK_STR"
symbol_kind: "func"
signature: |
#define MG_MK_STR(str_literal);
---
Macro for initializing mg_str.
---
title: "Utilities"
symbol_kind: "intro"
decl_name: "util.h"
---
{
"items": [
{
"type": "markdown",
"name": "intro.md"
},
{
"type": "markdown",
"name": "mg_skip.md"
},
{
"type": "markdown",
"name": "mg_ncasecmp.md"
},
{
"type": "markdown",
"name": "mg_casecmp.md"
},
{
"type": "markdown",
"name": "mg_vcmp.md"
},
{
"type": "markdown",
"name": "mg_vcasecmp.md"
},
{
"type": "markdown",
"name": "mg_base64_decode.md"
},
{
"type": "markdown",
"name": "mg_base64_encode.md"
},
{
"type": "markdown",
"name": "mg_stat.md"
},
{
"type": "markdown",
"name": "mg_fopen.md"
},
{
"type": "markdown",
"name": "mg_open.md"
},
{
"type": "markdown",
"name": "mg_start_thread.md"
},
{
"type": "markdown",
"name": "mg_conn_addr_to_str.md"
},
{
"type": "markdown",
"name": "mg_sock_to_str.md"
},
{
"type": "markdown",
"name": "mg_sock_addr_to_str.md"
},
{
"type": "markdown",
"name": "mg_hexdump.md"
},
{
"type": "markdown",
"name": "mg_hexdump_connection.md"
},
{
"type": "markdown",
"name": "mg_avprintf.md"
},
{
"type": "markdown",
"name": "mg_is_big_endian.md"
},
{
"type": "markdown",
"name": "mg_next_comma_list_entry.md"
},
{
"type": "markdown",
"name": "mg_match_prefix.md"
},
{
"type": "markdown",
"name": "mg_mk_str.md"
},
{
"type": "markdown",
"name": "MG_MK_STR.md"
}
]
}
---
title: "mg_avprintf()"
decl_name: "mg_avprintf"
symbol_kind: "func"
signature: |
int mg_avprintf(char **buf, size_t size, const char *fmt, va_list ap);
---
Print message to buffer. If buffer is large enough to hold the message,
return buffer. If buffer is to small, allocate large enough buffer on heap,
and return allocated buffer.
This is a supposed use case:
char buf[5], *p = buf;
p = mg_avprintf(&p, sizeof(buf), "%s", "hi there");
use_p_somehow(p);
if (p != buf) {
free(p);
}
The purpose of this is to avoid malloc-ing if generated strings are small.
---
title: "mg_base64_decode()"
decl_name: "mg_base64_decode"
symbol_kind: "func"
signature: |
int mg_base64_decode(const unsigned char *s, int len, char *dst);
---
Decode base64-encoded string `s`, `len` into the destination `dst`.
Destination has to have enough space to hold decoded buffer.
Decoding stops either when all string has been decoded, or invalid
character appeared.
Destination is '\0'-terminated.
Return number of decoded characters. On success, that should be equal to
`len`. On error (invalid character) the return value is smaller then `len`.
---
title: "mg_base64_encode()"
decl_name: "mg_base64_encode"
symbol_kind: "func"
signature: |
void mg_base64_encode(const unsigned char *src, int src_len, char *dst);
---
Base64-encode chunk of memory `src`, `src_len` into the destination `dst`.
Destination has to have enough space to hold encoded buffer.
Destination is '\0'-terminated.
---
title: "mg_casecmp()"
decl_name: "mg_casecmp"
symbol_kind: "func"
signature: |
int mg_casecmp(const char *s1, const char *s2);
---
Cross-platform version of `strcasecmp()`.
---
title: "mg_conn_addr_to_str()"
decl_name: "mg_conn_addr_to_str"
symbol_kind: "func"
signature: |
void mg_conn_addr_to_str(struct mg_connection *nc, char *buf, size_t len,
int flags);
---
Convert connection's local or remote address into string.
The `flags` parameter is a bit mask that controls the behavior,
see `MG_SOCK_STRINGIFY_*` definitions.
- MG_SOCK_STRINGIFY_IP - print IP address
- MG_SOCK_STRINGIFY_PORT - print port number
- MG_SOCK_STRINGIFY_REMOTE - print remote peer's IP/port, not local address
If both port number and IP address are printed, they are separated by `:`.
If compiled with `-DMG_ENABLE_IPV6`, IPv6 addresses are supported.
---
title: "mg_fopen()"
decl_name: "mg_fopen"
symbol_kind: "func"
signature: |
FILE *mg_fopen(const char *path, const char *mode);
---
Open the given file and return a file stream.
`path` and `mode` should be UTF8 encoded.
Return value is the same as for the `fopen()` call.
---
title: "mg_hexdump()"
decl_name: "mg_hexdump"
symbol_kind: "func"
signature: |
int mg_hexdump(const void *buf, int len, char *dst, int dst_len);
---
Generates human-readable hexdump of memory chunk.
Takes a memory buffer `buf` of length `len` and creates a hex dump of that
buffer in `dst`. Generated output is a-la hexdump(1).
Return length of generated string, excluding terminating `\0`. If returned
length is bigger than `dst_len`, overflow bytes are discarded.
---
title: "mg_hexdump_connection()"
decl_name: "mg_hexdump_connection"
symbol_kind: "func"
signature: |
void mg_hexdump_connection(struct mg_connection *nc, const char *path,
const void *buf, int num_bytes, int ev);
---
Generates human-readable hexdump of the data sent or received by connection.
`path` is a file name where hexdump should be written. `num_bytes` is
a number of bytes sent/received. `ev` is one of the `MG_*` events sent to
an event handler. This function is supposed to be called from the
event handler.
---
title: "mg_is_big_endian()"
decl_name: "mg_is_big_endian"
symbol_kind: "func"
signature: |
int mg_is_big_endian(void);
---
Return true if target platform is big endian.
---
title: "mg_match_prefix()"
decl_name: "mg_match_prefix"
symbol_kind: "func"
signature: |
int mg_match_prefix(const char *pattern, int pattern_len, const char *str);
---
Match 0-terminated string (mg_match_prefix) or string with given length
mg_match_prefix_n against a glob pattern.
Match is case-insensitive. Return number of bytes matched, or -1 if no match.
---
title: "mg_mk_str()"
decl_name: "mg_mk_str"
symbol_kind: "func"
signature: |
struct mg_str mg_mk_str(const char *s);
---
A helper function for creating mg_str struct from plain C string.
`NULL` is allowed and becomes `{NULL, 0}`.
---
title: "mg_ncasecmp()"
decl_name: "mg_ncasecmp"
symbol_kind: "func"
signature: |
int mg_ncasecmp(const char *s1, const char *s2, size_t len);
---
Cross-platform version of `strncasecmp()`.
---
title: "mg_next_comma_list_entry()"
decl_name: "mg_next_comma_list_entry"
symbol_kind: "func"
signature: |
const char *mg_next_comma_list_entry(const char *list, struct mg_str *val,
struct mg_str *eq_val);
---
A helper function for traversing a comma separated list of values.
It returns a list pointer shifted to the next value, or NULL if the end
of the list found.
Value is stored in val vector. If value has form "x=y", then eq_val
vector is initialized to point to the "y" part, and val vector length
is adjusted to point only to "x".
If list is just a comma separated list of entries, like "aa,bb,cc" then
`eq_val` will contain zero-length string.
The purpose of this function is to parse comma separated string without
any copying/memory allocation.
---
title: "mg_open()"
decl_name: "mg_open"
symbol_kind: "func"
signature: |
int mg_open(const char *path, int flag, int mode);
---
Open the given file and return a file stream.
`path` should be UTF8 encoded.
Return value is the same as for the `open()` syscall.
---
title: "mg_skip()"
decl_name: "mg_skip"
symbol_kind: "func"
signature: |
const char *mg_skip(const char *s, const char *end_string,
const char *delimiters, struct mg_str *v);
---
Fetch substring from input string `s`, `end` into `v`.
Skips initial delimiter characters. Records first non-delimiter character
as the beginning of substring `v`. Then scans the rest of the string
until a delimiter character or end-of-string is found.
`delimiters` is a 0-terminated string containing delimiter characters.
Either one of `delimiters` or `end_string` terminates the search.
Return an `s` pointer, advanced forward where parsing stopped.
---
title: "mg_sock_addr_to_str()"
decl_name: "mg_sock_addr_to_str"
symbol_kind: "func"
signature: |
void mg_sock_addr_to_str(const union socket_address *sa, char *buf, size_t len,
int flags);
---
Convert socket's address into string.
`flags` is MG_SOCK_STRINGIFY_IP and/or MG_SOCK_STRINGIFY_PORT.
---
title: "mg_sock_to_str()"
decl_name: "mg_sock_to_str"
symbol_kind: "func"
signature: |
void mg_sock_to_str(sock_t sock, char *buf, size_t len, int flags);
---
Legacy interface.
---
title: "mg_start_thread()"
decl_name: "mg_start_thread"
symbol_kind: "func"
signature: |
void *mg_start_thread(void *(*thread_func);
---
Start a new detached thread.
Arguments and semantic is the same as pthead's `pthread_create()`.
`thread_func` is a thread function, `thread_func_param` is a parameter
that is passed to the thread function.
---
title: "mg_stat()"
decl_name: "mg_stat"
symbol_kind: "func"
signature: |
int mg_stat(const char *path, cs_stat_t *st);
---
Perform a 64-bit `stat()` call against given file.
`path` should be UTF8 encoded.
Return value is the same as for `stat()` syscall.
---
title: "mg_vcasecmp()"
decl_name: "mg_vcasecmp"
symbol_kind: "func"
signature: |
int mg_vcasecmp(const struct mg_str *str2, const char *str1);
---
Cross-platform version of `strncasecmp()` where first string is
specified by `struct mg_str`.
---
title: "mg_vcmp()"
decl_name: "mg_vcmp"
symbol_kind: "func"
signature: |
int mg_vcmp(const struct mg_str *str2, const char *str1);
---
Cross-platform version of `strcmp()` where where first string is
specified by `struct mg_str`.
== Design Concept
Mongoose is a multi-protocol networking library that implements non-blocking,
asyncronous IO and provides event-based API. It has three basic data structures:
- link:#_struct_mg_mgr[`struct mg_mgr`] is an event manager
that holds all active connections
- link:#_struct_mg_connection[`struct mg_connection`] describes a connection
- link:#_struct_mbuf[`struct mbuf`] describes data buffer
(received or sent data)
Connections could be either *listening*, *outbound* or *inbound*.
Outbound connections are created by link:#_mg_connect[`mg_connect()`] call.
Listening connections are created by link:#_mg_bind[`mg_bind()`] call.
Inbound connections are those accepted by a listening connection.
Each connection is described by
link:#_struct_mg_connection[`struct mg_connection`] structure, which has
a number of fields like socket, event handler function, send/receive buffer,
flags, et cetera.
Mongoose usage pattern is to declare and initialize event manager, create
connections and create an event loop by calling
link:#_mg_mgr_poll[`mg_mgr_poll()`] in a loop.
link:#_mg_mgr_poll[`mg_mgr_poll()`] iterates over all sockets,
accepts new connections, sends and receives data, closes connections,
and calls event handler functions for the respective events.
=== Memory buffers
Each connection has send and receive buffer,
link:#_struct_mg_connection[`struct mg_connection::send_mbuf`]
and
link:#_struct_mg_connection[`struct mg_connection::recv_mbuf`] respectively.
When data arrives,
Mongoose appends received data to the `recv_mbuf` and
triggers `MG_EV_RECV` event. User may send data back by calling one of the
output functions, like link:#_mg_send[`mg_send()`] or
link:#_mg_printf[`mg_printf()`]. Output functions append data to the
`send_mbuf`. When Mongoose
successfully writes data to the socket, it discards data from
link:#_struct_mg_connection[`mg_connection::send_mbuf`] and
sends `MG_EV_SEND` event. When connection is closed, `MG_EV_CLOSE` event is sent.
image::mongoose/mbuf.png[width="600",align="center"]
=== Event handler function
Each connection has an event handler function associated with it. That
function must be implemented by user. Event handler is the key element of
the Mongoose application, since it defines application's behavior. This is how
an event handler function looks like:
[source,c]
----
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
switch (ev) {
/* Event handler code that defines behavior of the connection */
...
}
}
----
struct mg_connection *nc::
Connection that has received an event.
int ev::
Event number, defined in `mongoose.h`. For example, when data arrives
on inbound connection `ev` would be `MG_EV_RECV`.
void *ev_data::
This pointer points to the event-specific data, and it has different
meaning for different events. For example, for `MG_EV_RECV` event,
`ev_data` is an `int *` pointer, pointing to the number of bytes received
from the remote peer and saved into the receive IO buffer. Exact meaning
of `ev_data` is described for each event. Protocol-specific events usually
have `ev_data` pointing to structures that hold protocol-specific information.
NOTE: link:#_struct_mg_connection[`struct mg_connection`] has `void *user_data`
which is a placeholder for a application-specific data. Mongoose does not use
that pointer. Event handler can store any kind of information there.
=== Events
Mongoose accepts incoming connections, reads and writes data, and
calls specified event handler for each connection when appropriate. Typical
event sequence is this:
- For outbound connection: `MG_EV_CONNECT` -> (`MG_EV_RECV`, `MG_EV_SEND`, `MG_EV_POLL` ...) -> `MG_EV_CLOSE`
- For inbound connection: `MG_EV_ACCEPT` -> (`MG_EV_RECV`, `MG_EV_SEND`, `MG_EV_POLL` ...) -> `MG_EV_CLOSE`
Below is a list
of core events triggered by Mongoose (note that each protocol triggers
protocol-specific events in addition to the core ones):
MG_EV_ACCEPT:: sent when new server connection is accepted by a
listening connection. `void *ev_data` is `union socket_address`
of the remote peer.
MG_EV_CONNECT:: sent when a new outbound connection created by
link:#_mg_connect[`mg_connect()`]
either failed or succeeded. `void *ev_data` is `int *success`.
If `success` is 0, then connection has been established,
otherwise it contains error code. See
link:#_mg_connect_opt[`mg_connect_opt()`] function for code example.
MG_EV_RECV:: New data is received and appended to the end of `recv_mbuf`.
`void *ev_data` is `int *num_received_bytes`. Typically, event handler
should check received data in `nc->recv_mbuf`,
discard processed data by calling link:#_mbuf_remove[`mbuf_remove()`],
set connection flags `nc->flags` if necessary
(see link:#_struct_mg_connection[`struct mg_connection`]), and write
data the remote peer by output functions like link:#_mg_send[`mg_send()`].
WARNING: Mongoose uses `realloc()` to expand receive buffer.
It is user's responsibility to discard processed
data from the beginning of receive buffer, note the `mbuf_remove()`
call in the example above.
MG_EV_SEND:: Mongoose has written data to the remote peer and discarded
written data from the
link:#_struct_mg_connection[`mg_connection::send_mbuf`]. `void *ev_data`
is `int *num_sent_bytes`.
NOTE: Mongoose output functions only append
data to the `mg_connection::send_mbuf`, they do not do any socket writes.
An actual IO is done by link:#_mg_mgr_poll[`mg_mgr_poll()`]. `MG_EV_SEND` event
is just a notification about an IO has been done.
MG_EV_POLL:: Sent to all connections on each invocation of
link:#_mg_mgr_poll[`mg_mgr_poll()`].
This event could be used to do any housekeeping, for example check whether
certain timeout has expired and close the connection, or send heartbeet
message, et cetera.
MG_EV_TIMER:: Sent to the connection if
link:#_mg_set_timer[`mg_set_timer()`] was called.
=== Connection flags
Each connection has a `flags` bit field. Some flags are set by Mongoose, for
example if a user creates an outbound UDP connection using `udp://1.2.3.4:5678`
address, Mongoose is going to set `MG_F_UDP` flag for that connection. Other flags
are meant to be set only by user event handler to tell Mongoose how to behave.
Below is a list of connection flags that are meant to be set by event handlers:
* `MG_F_FINISHED_SENDING_DATA` tells Mongoose that all data has been
appended to the `send_mbuf`. As soon as Mongoose sends it to the
socket, the connection will be closed.
* `MG_F_BUFFER_BUT_DONT_SEND` tells Mongoose to append data to the
`send_mbuf` but hold on sending it, because the data will be modified
later and then will be sent by clearing `MG_F_BUFFER_BUT_DONT_SEND` flag.
* `MG_F_CLOSE_IMMEDIATELY` tells Mongoose to close the connection
immediately, usually after some error
* `MG_F_USER_1`, `MG_F_USER_2`, `MG_F_USER_3`, `MG_F_USER_4` could be
used by a developer to store application-specific state
Flags below are set by Mongoose:
* `MG_F_SSL_HANDSHAKE_DONE` SSL only, set when SSL handshake is done.
* `MG_F_CONNECTING` set when connection is in connecting state after
`mg_connect()` call but connect did not finish yet.
* `MG_F_LISTENING` set for all listening connections
* `MG_F_UDP` set if connection is UDP
* `MG_F_IS_WEBSOCKET` set if connection is a Websocket connection
* `MG_F_WEBSOCKET_NO_DEFRAG` should be set by a user if user wants to switch
off automatic Websocket frame defragmentation
---
title: Connection flags
---
Each connection has a `flags` bit field. Some flags are set by Mongoose, for
example if a user creates an outbound UDP connection using `udp://1.2.3.4:5678`
address, Mongoose is going to set `MG_F_UDP` flag for that connection. Other
flags are meant to be set only by user event handler to tell Mongoose how to
behave. Below is a list of connection flags that are meant to be set by event
handlers:
* `MG_F_FINISHED_SENDING_DATA` tells Mongoose that all data has been appended
to the `send_mbuf`. As soon as Mongoose sends it to the socket, the
connection will be closed.
* `MG_F_BUFFER_BUT_DONT_SEND` tells Mongoose to append data to the `send_mbuf`
but hold on sending it, because the data will be modified later and then will
be sent by clearing `MG_F_BUFFER_BUT_DONT_SEND` flag.
* `MG_F_CLOSE_IMMEDIATELY` tells Mongoose to close the connection immediately,
usually after some error
* `MG_F_USER_1`, `MG_F_USER_2`, `MG_F_USER_3`, `MG_F_USER_4` could be used by a
developer to store application-specific state
Flags below are set by Mongoose:
* `MG_F_SSL_HANDSHAKE_DONE` SSL only, set when SSL handshake is done.
* `MG_F_CONNECTING` set when connection is in connecting state after
`mg_connect()` call but connect did not finish yet.
* `MG_F_LISTENING` set for all listening connections
* `MG_F_UDP` set if connection is UDP
* `MG_F_IS_WEBSOCKET` set if connection is a Websocket connection
* `MG_F_WEBSOCKET_NO_DEFRAG` should be set by a user if user wants to switch
off automatic Websocket frame defragmentation
---
title: Event handler function
---
Each connection has an event handler function associated with it. That function
must be implemented by user. Event handler is the key element of the Mongoose
application, since it defines application's behavior. This is how an event
handler function looks like:
```c
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
switch (ev) {
/* Event handler code that defines behavior of the connection */
...
}
}
```
- `struct mg_connection *nc`: Connection that has received an event.
- `int ev`: Event number, defined in `mongoose.h`. For example, when data
arrives on inbound connection `ev` would be `MG_EV_RECV`.
- `void *ev_data`: This pointer points to the event-specific data, and it has
different meaning for different events. For example, for `MG_EV_RECV` event,
`ev_data` is an `int *` pointer, pointing to the number of bytes received
from the remote peer and saved into the receive IO buffer. Exact meaning of
`ev_data` is described for each event. Protocol-specific events usually have
`ev_data` pointing to structures that hold protocol-specific information.
NOTE: `struct mg_connection` has `void *user_data` which is a placeholder for
an application-specific data. Mongoose does not use that pointer. Event handler
can store any kind of information there.
---
title: Events
---
Mongoose accepts incoming connections, reads and writes data, and calls
specified event handler for each connection when appropriate. Typical event
sequence is this:
- For outbound connection: `MG_EV_CONNECT` -> (`MG_EV_RECV`, `MG_EV_SEND`,
`MG_EV_POLL` ...) -> `MG_EV_CLOSE`
- For inbound connection: `MG_EV_ACCEPT` -> (`MG_EV_RECV`, `MG_EV_SEND`,
`MG_EV_POLL` ...) -> `MG_EV_CLOSE`
Below is a list of core events triggered by Mongoose (note that each protocol
triggers protocol-specific events in addition to the core ones):
- `MG_EV_ACCEPT`: sent when new server connection is accepted by a listening
connection. `void *ev_data` is `union socket_address` of the remote peer.
- `MG_EV_CONNECT`: sent when a new outbound connection created by `mg_connect()`
either failed or succeeded. `void *ev_data` is `int *success`. If `success`
is 0, then connection has been established, otherwise it contains error code.
See `mg_connect_opt()` function for code example.
- `MG_EV_RECV`: New data is received and appended to the end of `recv_mbuf`.
`void *ev_data` is `int *num_received_bytes`. Typically, event handler should
check received data in `nc->recv_mbuf`, discard processed data by calling
`mbuf_remove()`, set connection flags `nc->flags` if necessary (see `struct
mg_connection`), and write data the remote peer by output functions like
`mg_send()`.
**WARNING**: Mongoose uses `realloc()` to expand receive buffer. It is
user's responsibility to discard processed data from the beginning of receive
buffer, note the `mbuf_remove()` call in the example above.
- `MG_EV_SEND`: Mongoose has written data to the remote peer and discarded
written data from the `mg_connection::send_mbuf`. `void *ev_data` is `int
*num_sent_bytes`.
**NOTE**: Mongoose output functions only append data to the
`mg_connection::send_mbuf`, they do not do any socket writes. An actual IO
is done by `mg_mgr_poll()`. `MG_EV_SEND` event is just a notification about
an IO has been done.
- `MG_EV_POLL`: Sent to all connections on each invocation of `mg_mgr_poll()`.
This event could be used to do any housekeeping, for example check whether
certain timeout has expired and close the connection, or send heartbeet
message, et cetera.
- `MG_EV_TIMER`: Sent to the connection if `mg_set_timer()` was called.
---
title: Design Concept
---
Mongoose is a multi-protocol networking library that implements non-blocking,
asyncronous IO and provides event-based API. It has three basic data
structures:
- `struct mg_mgr` is an event manager that holds all active connections
- `struct mg_connection` describes a connection
- `struct mbuf` describes data buffer (received or sent data)
Connections could be either *listening*, *outbound* or *inbound*. Outbound
connections are created by `mg_connect()` call. Listening connections are
created by `mg_bind()` call. Inbound connections are those accepted by a
listening connection. Each connection is described by `struct mg_connection`
structure, which has a number of fields like socket, event handler function,
send/receive buffer, flags, et cetera.
Mongoose usage pattern is to declare and initialize event manager, create
connections and create an event loop by calling `mg_mgr_poll()` in a loop.
`mg_mgr_poll()` iterates over all sockets, accepts new connections, sends and
receives data, closes connections, and calls event handler functions for the
respective events.
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{ "type": "markdown", "name": "intro.md" },
{ "type": "markdown", "name": "memory-buffers.md" },
{ "type": "markdown", "name": "event-handler.md" },
{ "type": "markdown", "name": "events.md" },
{ "type": "markdown", "name": "conn-flags.md" }
]
}
---
title: Memory buffers
---
Each connection has send and receive buffer, `struct mg_connection::send_mbuf`
and `struct mg_connection::recv_mbuf` respectively. When data arrives,
Mongoose appends received data to the `recv_mbuf` and triggers `MG_EV_RECV`
event. User may send data back by calling one of the output functions, like
`mg_send()` or `mg_printf()`. Output functions append data to the `send_mbuf`.
When Mongoose successfully writes data to the socket, it discards data from
`struct mg_connection::send_mbuf` and sends `MG_EV_SEND` event. When connection
is closed, `MG_EV_CLOSE` event is sent.
![](mbuf.png)
:toc2:
:toclevels: 2
:source-highlighter: pygments
:pygments-style: xcode
:docinfo:
= Multi-Protocol Networking Library
include::tutorial.adoc[]
include::concept.adoc[]
include::build_opts.adoc[]
== API Reference
include::mbuf.adoc[]
include::net.adoc[]
include::http.adoc[]
include::json-rpc.adoc[]
include::dns.adoc[]
include::dns-server.adoc[]
include::mqtt.adoc[]
include::mqtt-broker.adoc[]
include::coap.adoc[]
include::util.adoc[]
{
"items": [
{ "type": "section", "name": "usage-example" },
{ "type": "section", "name": "design-concept" },
{ "type": "section", "name": "build-options" },
{ "type": "flat_sections_set", "name": "c-api" }
]
}
---
title: Usage Example
---
== Usage Example
- Copy `mongoose.c` and `mongoose.h` to your build tree
- Write code that uses Mongoose API, e.g. in `my_app.c`
- Compile application: `$ cc my_app.c mongoose.c`
1. Copy `mongoose.c` and `mongoose.h` to your build tree
2. Write code that uses Mongoose API, e.g. in `my_app.c`
3. Compile application: `$ cc my_app.c mongoose.c`
```c
#include "mongoose.h" // Include Mongoose API definitions
[source,c]
.my_app.c
----
#include "mongoose.h" // <1>
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) { // <2>
// Define an event handler function
static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
struct mbuf *io = &nc->recv_mbuf;
switch (ev) {
......@@ -27,23 +27,18 @@ static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) { // <2>
int main(void) {
struct mg_mgr mgr;
mg_mgr_init(&mgr, NULL); // <3>
mg_mgr_init(&mgr, NULL); // Initialize event manager object
// Note that many connections can be added to a single event manager
// Connections can be created at any point, e.g. in event handler function
mg_bind(&mgr, "1234", ev_handler); // <4>
mg_bind(&mgr, "1234", ev_handler); // Create listening connection and add it to the event manager
for (;;) { // <5>
for (;;) { // Start infinite event loop
mg_mgr_poll(&mgr, 1000);
}
mg_mgr_free(&mgr);
return 0;
}
----
```
<1> Include Mongoose API definitions
<2> Define an event handler function
<3> Initialize event manager object
<4> Create listening connection and add it to the event manager
<5> Start infinite event loop
{
"items": [
{ "type": "markdown", "name": "intro.md" }
]
}
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