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res_pjsip_header_funcs: Add PJSIP_HEADERS() ability to read header by pattern 

PJSIP currently does not provide a function to replace SIP_HEADERS() function to get a list of headers from INVITE request.
It may be used to get all X- headers in case the actual set and names of headers unknown.

ASTERISK-29389

Change-Id: Ic09d395de71a0021e0d6c5c29e1e19d689079f8b
This commit is contained in:
Igor Goncharovsky 2021-04-13 13:36:17 +06:00 committed by Friendly Automation
parent b40e97b1d7
commit 8da1466478
2 changed files with 188 additions and 9 deletions
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5
doc/CHANGES-staging/pjsip_read_headers.txt Normal file
View File

@ -0,0 +1,5 @@
Subject: chan_pjsip
Add function PJSIP_HEADERS() to get list of headers by pattern in the same way as SIP_HEADERS() do.
Add ability to read header by pattern using PJSIP_HEADER().

192
res/res_pjsip_header_funcs.c
View File

@ -46,7 +46,10 @@
<parameter name="action" required="true">
<enumlist>
<enum name="read"><para>Returns instance <replaceable>number</replaceable>
of header <replaceable>name</replaceable>.</para></enum>
of header <replaceable>name</replaceable>. A <literal>*</literal>
may be appended to <replaceable>name</replaceable> to iterate over all
headers <emphasis>beginning with</emphasis> <replaceable>name</replaceable>.
</para></enum>
<enum name="add"><para>Adds a new header <replaceable>name</replaceable>
to this session.</para></enum>
@ -88,6 +91,9 @@
<para>; Set 'via2' to the value of the 2nd 'Via' header.</para>
<para>exten => 1,1,Set(via2=${PJSIP_HEADER(read,Via,2)})</para>
<para>;</para>
<para>; Set 'xhdr' to the value of the 1sx X-header.</para>
<para>exten => 1,1,Set(xhdr=${PJSIP_HEADER(read,X-*,1)})</para>
<para>;</para>
<para>; Add an 'X-Myheader' header with the value of 'myvalue'.</para>
<para>exten => 1,1,Set(PJSIP_HEADER(add,X-MyHeader)=myvalue)</para>
<para>;</para>
@ -139,6 +145,29 @@
</note>
</description>
</function>
<function name="PJSIP_HEADERS" language="en_US">
<synopsis>
Gets the list of SIP header names from an INVITE message.
</synopsis>
<syntax>
<parameter name="prefix">
<para>If specified, only the headers matching the given prefix are returned.</para>
</parameter>
</syntax>
<description>
<para>Returns a comma-separated list of header names (without values) from the
INVITE message. Multiple headers with the same name are included in the list only once.
</para>
<para>For example, <literal>${PJSIP_HEADERS(Co)}</literal> might return
<literal>Contact,Content-Length,Content-Type</literal>. As a practical example,
you may use <literal>${PJSIP_HEADERS(X-)}</literal> to enumerate optional extended
headers.</para>
</description>
<see-also>
<ref type="function">PJSIP_HEADER</ref>
</see-also>
</function>
***/
/*! \brief Linked list for accumulating headers */
@ -240,6 +269,92 @@ static pjsip_hdr *find_header(struct hdr_list *list, const char *header_name,
return hdr;
}
/*!
* \internal
* \brief Implements PJSIP_HEADERS by searching for the requested header prefix.
*
* Retrieve the header_datastore.
* Search for the all matching headers.
* Validate the pjsip_hdr found.
* Parse pjsip_hdr into a name and copy to the buffer.
* Return the value.
*/
static int read_headers(void *obj)
{
struct header_data *data = obj;
size_t len = strlen(data->header_name);
pjsip_hdr *hdr = NULL;
char *pj_hdr_string;
int pj_hdr_string_len;
char *p;
char *pos;
size_t plen, wlen = 0;
struct hdr_list_entry *le;
struct hdr_list *list;
RAII_VAR(struct ast_datastore *, datastore,
ast_sip_session_get_datastore(data->channel->session, header_datastore.type),
ao2_cleanup);
if (!datastore || !datastore->data) {
ast_debug(1, "There was no datastore from which to read headers.\n");
return -1;
}
list = datastore->data;
pj_hdr_string = ast_alloca(data->len);
AST_LIST_TRAVERSE(list, le, nextptr) {
if (pj_strnicmp2(&le->hdr->name, data->header_name, len) == 0) {
/* Found matched header, append to buf */
hdr = le->hdr;
pj_hdr_string_len = pjsip_hdr_print_on(hdr, pj_hdr_string, data->len - 1);
if (pj_hdr_string_len == -1) {
ast_log(AST_LOG_ERROR,
"Not enought buffer space in pjsip_hdr_print_on\n");
return -1;
}
pj_hdr_string[pj_hdr_string_len] = '\0';
p = strchr(pj_hdr_string, ':');
if (!p) {
ast_log(AST_LOG_WARNING,
"A malformed header was returned from pjsip_hdr_print_on\n");
continue;
}
pj_hdr_string[p - pj_hdr_string] = '\0';
p = ast_strip(pj_hdr_string);
plen = strlen(p);
if (wlen + plen + 1 > data->len) {
ast_log(AST_LOG_ERROR,
"Buffer isn't big enough to hold header value. %zu > %zu\n", plen + 1,
data->len);
return -1;
}
pos = strstr(data->buf, p);
if (pos && pos[1] == ',') {
if (pos == data->buf) {
continue;
} else if (pos[-1] == ',') {
continue;
}
}
ast_copy_string(data->buf + wlen, p, data->len - wlen);
wlen += plen;
ast_copy_string(data->buf + wlen, ",", data->len - wlen);
wlen++;
}
}
if (wlen == 0) {
ast_debug(1, "There was no header named %s.\n", data->header_name);
return -1;
} else {
data->buf[wlen-1] = '\0';
}
return 0;
}
/*!
* \internal
@ -254,11 +369,15 @@ static pjsip_hdr *find_header(struct hdr_list *list, const char *header_name,
static int read_header(void *obj)
{
struct header_data *data = obj;
size_t len = strlen(data->header_name);
pjsip_hdr *hdr = NULL;
char *pj_hdr_string;
size_t pj_hdr_string_len;
int pj_hdr_string_len;
char *p;
size_t plen;
struct hdr_list_entry *le;
struct hdr_list *list;
int i = 1;
RAII_VAR(struct ast_datastore *, datastore,
ast_sip_session_get_datastore(data->channel->session, header_datastore.type),
ao2_cleanup);
@ -268,8 +387,20 @@ static int read_header(void *obj)
return -1;
}
hdr = find_header((struct hdr_list *) datastore->data, data->header_name,
data->header_number);
list = datastore->data;
AST_LIST_TRAVERSE(list, le, nextptr) {
if (data->header_name[len - 1] == '*') {
if (pj_strnicmp2(&le->hdr->name, data->header_name, len - 1) == 0 && i++ == data->header_number) {
hdr = le->hdr;
break;
}
} else {
if (pj_stricmp2(&le->hdr->name, data->header_name) == 0 && i++ == data->header_number) {
hdr = le->hdr;
break;
}
}
}
if (!hdr) {
ast_debug(1, "There was no header named %s.\n", data->header_name);
@ -277,7 +408,13 @@ static int read_header(void *obj)
}
pj_hdr_string = ast_alloca(data->len);
pj_hdr_string_len = pjsip_hdr_print_on(hdr, pj_hdr_string, data->len);
pj_hdr_string_len = pjsip_hdr_print_on(hdr, pj_hdr_string, data->len - 1);
if (pj_hdr_string_len == -1) {
ast_log(AST_LOG_ERROR,
"Not enought buffer space in pjsip_hdr_print_on\n");
return -1;
}
pj_hdr_string[pj_hdr_string_len] = '\0';
p = strchr(pj_hdr_string, ':');
@ -434,13 +571,44 @@ static int remove_header(void *obj)
return 0;
}
/*!
* \brief Read list of unique SIP headers
*/
static int func_read_headers(struct ast_channel *chan, const char *function, char *data, char *buf, size_t len)
{
struct ast_sip_channel_pvt *channel = chan ? ast_channel_tech_pvt(chan) : NULL;
struct header_data header_data;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(header_pattern);
);
AST_STANDARD_APP_ARGS(args, data);
if (!chan || strncmp(ast_channel_name(chan), "PJSIP/", 6)) {
ast_log(LOG_ERROR, "This function requires a PJSIP channel.\n");
return -1;
}
if (ast_strlen_zero(args.header_pattern)) {
ast_log(AST_LOG_ERROR, "This function requires a pattern.\n");
return -1;
}
header_data.channel = channel;
header_data.header_name = args.header_pattern;
header_data.header_value = NULL;
header_data.buf = buf;
header_data.len = len;
return ast_sip_push_task_wait_serializer(channel->session->serializer, read_headers, &header_data);
}
/*!
* \brief Implements function 'read' callback.
*
* Valid actions are 'read' and 'remove'.
*/
static int func_read_header(struct ast_channel *chan, const char *function, char *data,
char *buf, size_t len)
static int func_read_header(struct ast_channel *chan, const char *function, char *data, char *buf, size_t len)
{
struct ast_sip_channel_pvt *channel = chan ? ast_channel_tech_pvt(chan) : NULL;
struct header_data header_data;
@ -480,8 +648,7 @@ static int func_read_header(struct ast_channel *chan, const char *function, char
header_data.len = len;
if (!strcasecmp(args.action, "read")) {
return ast_sip_push_task_wait_serializer(channel->session->serializer,
read_header, &header_data);
return ast_sip_push_task_wait_serializer(channel->session->serializer, read_header, &header_data);
} else if (!strcasecmp(args.action, "remove")) {
return ast_sip_push_task_wait_serializer(channel->session->serializer,
remove_header, &header_data);
@ -561,6 +728,11 @@ static struct ast_custom_function pjsip_header_function = {
.write = func_write_header,
};
static struct ast_custom_function pjsip_headers_function = {
.name = "PJSIP_HEADERS",
.read = func_read_headers
};
/*!
* \internal
* \brief Session supplement callback for outgoing INVITE requests
@ -604,6 +776,7 @@ static int load_module(void)
{
ast_sip_session_register_supplement(&header_funcs_supplement);
ast_custom_function_register(&pjsip_header_function);
ast_custom_function_register(&pjsip_headers_function);
return AST_MODULE_LOAD_SUCCESS;
}
@ -611,6 +784,7 @@ static int load_module(void)
static int unload_module(void)
{
ast_custom_function_unregister(&pjsip_header_function);
ast_custom_function_unregister(&pjsip_headers_function);
ast_sip_session_unregister_supplement(&header_funcs_supplement);
return 0;
}