[asterisk-commits] rizzo: trunk r75034 - in /trunk: include/asterisk/rtp.h main/rtp.c
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Fri Jul 13 11:22:10 CDT 2007
Author: rizzo
Date: Fri Jul 13 11:22:09 2007
New Revision: 75034
URL: http://svn.digium.com/view/asterisk?view=rev&rev=75034
Log:
Small improvement to the STUN support so it can be used by
sockets other than RTP ones.
The main change is a new API function in main/rtp.c (see there
for a description)
int ast_stun_request(int s, struct sockaddr_in *dst,
const char *username, struct sockaddr_in *answer)
which can be used to send an STUN request on a socket, and
optionally wait for a reply and store the STUN_MAPPED_ADDRESS
into the 'answer' argument (obviously, the version that
waits for a reply is blocking, but this is no different
from DNS resolutions).
Internally there are minor modifications to let stun_handle_packet()
be somewhat configurable on how to parse the body of responses.
At the moment i am not committing any change to the clients,
but adding STUN client support is extremely simple, e.g. chan_sip.c
could do something like this:
+ add a variable to store the stun server address;
static struct sockaddr_in stunaddr = { 0, }; /*!< stun server address */
+ add code to parse a config file of the form "stunaddr=my.stun.server.org:3478"
(not shown for brevity);
+ right after binding the main sip socket, talk to the stun server to
determine the externally visible address
if (stunaddr.sin_addr.s_addr != 0)
ast_stun_request(sipsock, &stunaddr, NULL, &externip);
so now 'externip' is set with the externally visible address.
so it is really trivial.
Similarly ast_stun_request could be called when creating the RTP
socket (possibly adding a struct sockaddr_in field in the struct
ast_rtp to store the externalip).
Modified:
trunk/include/asterisk/rtp.h
trunk/main/rtp.c
Modified: trunk/include/asterisk/rtp.h
URL: http://svn.digium.com/view/asterisk/trunk/include/asterisk/rtp.h?view=diff&rev=75034&r1=75033&r2=75034
==============================================================================
--- trunk/include/asterisk/rtp.h (original)
+++ trunk/include/asterisk/rtp.h Fri Jul 13 11:22:09 2007
@@ -211,7 +211,22 @@
/*! \brief Enable STUN capability */
void ast_rtp_setstun(struct ast_rtp *rtp, int stun_enable);
-/*! \brief Send STUN request (??) */
+/*! \brief Generic STUN request
+ * send a generic stun request to the server specified.
+ * \param s the socket used to send the request
+ * \param dst the address of the STUN server
+ * \param username if non null, add the username in the request
+ * \param answer if non null, the function waits for a response and
+ * puts here the externally visible address.
+ * \return 0 on success, other values on error.
+ * The interface it may change in the future.
+ */
+int ast_stun_request(int s, struct sockaddr_in *dst,
+ const char *username, struct sockaddr_in *answer);
+
+/*! \brief Send STUN request for an RTP socket
+ * Deprecated, this is just a wrapper for ast_rtp_stun_request()
+ */
void ast_rtp_stun_request(struct ast_rtp *rtp, struct sockaddr_in *suggestion, const char *username);
/*! \brief The RTP bridge.
Modified: trunk/main/rtp.c
URL: http://svn.digium.com/view/asterisk/trunk/main/rtp.c?view=diff&rev=75034&r1=75033&r2=75034
==============================================================================
--- trunk/main/rtp.c (original)
+++ trunk/main/rtp.c Fri Jul 13 11:22:09 2007
@@ -449,29 +449,8 @@
return sizeof(struct ast_rtp);
}
-/*! \brief send a STUN BIND request to the given destination.
- * Optionally, add a username if specified.
- */
-void ast_rtp_stun_request(struct ast_rtp *rtp, struct sockaddr_in *suggestion, const char *username)
-{
- struct stun_header *req;
- unsigned char reqdata[1024];
- int reqlen, reqleft;
- struct stun_attr *attr;
-
- req = (struct stun_header *)reqdata;
- stun_req_id(req);
- reqlen = 0;
- reqleft = sizeof(reqdata) - sizeof(struct stun_header);
- req->msgtype = 0;
- req->msglen = 0;
- attr = (struct stun_attr *)req->ies;
- if (username)
- append_attr_string(&attr, STUN_USERNAME, username, &reqlen, &reqleft);
- req->msglen = htons(reqlen);
- req->msgtype = htons(STUN_BINDREQ);
- stun_send(rtp->s, suggestion, req);
-}
+/*! \brief callback type to be invoked on stun responses. */
+typedef int (stun_cb_f)(struct stun_attr *attr, void *arg);
/*! \brief handle an incoming STUN message.
*
@@ -479,8 +458,10 @@
* try to extract a bit of information, and possibly reply.
* At the moment this only processes BIND requests, and returns
* the externally visible address of the request.
+ * If a callback is specified, invoke it with the attribute.
*/
-static int stun_handle_packet(int s, struct sockaddr_in *src, unsigned char *data, size_t len)
+static int stun_handle_packet(int s, struct sockaddr_in *src,
+ unsigned char *data, size_t len, stun_cb_f *stun_cb, void *arg)
{
struct stun_header *hdr = (struct stun_header *)data;
struct stun_attr *attr;
@@ -518,6 +499,8 @@
ast_debug(1, "Inconsistent Attribute (length %d exceeds remaining msg len %d)\n", x, (int)len);
break;
}
+ if (stun_cb)
+ stun_cb(attr, arg);
if (stun_process_attr(&st, attr)) {
ast_debug(1, "Failed to handle attribute %s (%04x)\n", stun_attr2str(ntohs(attr->attr)), ntohs(attr->attr));
break;
@@ -569,6 +552,107 @@
}
}
return ret;
+}
+
+/*! \brief Extract the STUN_MAPPED_ADDRESS from the stun response.
+ * This is used as a callback for stun_handle_response
+ * when called from ast_stun_request.
+ */
+static int stun_get_mapped(struct stun_attr *attr, void *arg)
+{
+ struct stun_addr *addr = (struct stun_addr *)(attr + 1);
+ struct sockaddr_in *sa = (struct sockaddr_in *)arg;
+
+ if (ntohs(attr->attr) != STUN_MAPPED_ADDRESS || ntohs(attr->len) != 8)
+ return 1; /* not us. */
+ sa->sin_port = addr->port;
+ sa->sin_addr.s_addr = addr->addr;
+ return 0;
+}
+
+/*! \brief Generic STUN request
+ * Send a generic stun request to the server specified,
+ * possibly waiting for a reply and filling the 'reply' field with
+ * the externally visible address. Note that in this case the request
+ * will be blocking.
+ * (Note, the interface may change slightly in the future).
+ *
+ * \param s the socket used to send the request
+ * \param dst the address of the STUN server
+ * \param username if non null, add the username in the request
+ * \param answer if non null, the function waits for a response and
+ * puts here the externally visible address.
+ * \return 0 on success, other values on error.
+ */
+int ast_stun_request(int s, struct sockaddr_in *dst,
+ const char *username, struct sockaddr_in *answer)
+{
+ struct stun_header *req;
+ unsigned char reqdata[1024];
+ int reqlen, reqleft;
+ struct stun_attr *attr;
+ int res = 0;
+ int retry;
+
+ req = (struct stun_header *)reqdata;
+ stun_req_id(req);
+ reqlen = 0;
+ reqleft = sizeof(reqdata) - sizeof(struct stun_header);
+ req->msgtype = 0;
+ req->msglen = 0;
+ attr = (struct stun_attr *)req->ies;
+ if (username)
+ append_attr_string(&attr, STUN_USERNAME, username, &reqlen, &reqleft);
+ req->msglen = htons(reqlen);
+ req->msgtype = htons(STUN_BINDREQ);
+ for (retry = 0; retry < 3; retry++) { /* XXX make retries configurable */
+ /* send request, possibly wait for reply */
+ unsigned char reply_buf[1024];
+ fd_set rfds;
+ struct timeval to = { 3, 0 }; /* timeout, make it configurable */
+ struct sockaddr_in src;
+ int srclen;
+
+ res = stun_send(s, dst, req);
+ if (res < 0) {
+ ast_log(LOG_WARNING, "ast_stun_request send #%d failed error %d, retry\n",
+ retry, res);
+ continue;
+ }
+ if (answer == NULL)
+ break;
+ FD_ZERO(&rfds);
+ FD_SET(s, &rfds);
+ res = ast_select(s + 1, &rfds, NULL, NULL, &to);
+ if (res <= 0) /* timeout or error */
+ continue;
+ bzero(&src, sizeof(src));
+ srclen = sizeof(src);
+ /* XXX pass -1 in the size, because stun_handle_packet might
+ * write past the end of the buffer.
+ */
+ res = recvfrom(s, reply_buf, sizeof(reply_buf) - 1,
+ 0, (struct sockaddr *)&src, &srclen);
+ if (res < 0) {
+ ast_log(LOG_WARNING, "ast_stun_request recvfrom #%d failed error %d, retry\n",
+ retry, res);
+ continue;
+ }
+ bzero(answer, sizeof(struct sockaddr_in));
+ stun_handle_packet(s, &src, reply_buf, res,
+ stun_get_mapped, answer);
+ res = 0; /* signal regular exit */
+ break;
+ }
+ return res;
+}
+
+/*! \brief send a STUN BIND request to the given destination.
+ * Optionally, add a username if specified.
+ */
+void ast_rtp_stun_request(struct ast_rtp *rtp, struct sockaddr_in *suggestion, const char *username)
+{
+ ast_stun_request(rtp->s, suggestion, username, NULL);
}
/*! \brief List of current sessions */
@@ -1338,7 +1422,7 @@
* answers to requests, and it returns STUN_ACCEPT
* if the request is valid.
*/
- if ((stun_handle_packet(rtp->s, &sin, rtp->rawdata + AST_FRIENDLY_OFFSET, res) == STUN_ACCEPT) &&
+ if ((stun_handle_packet(rtp->s, &sin, rtp->rawdata + AST_FRIENDLY_OFFSET, res, NULL, NULL) == STUN_ACCEPT) &&
(!rtp->them.sin_port && !rtp->them.sin_addr.s_addr)) {
memcpy(&rtp->them, &sin, sizeof(rtp->them));
}
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