[sr-dev] git:master: core/tcp: clone received message over tcp in local buffer

Module: sip-router Branch: master Commit: 6ebd0a6bf1cbacf73f45ff42d368f22304bff11b URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=6ebd0a6… Author: Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; Committer: Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; Date: Fri Dec 2 13:05:55 2011 +0100 core/tcp: clone received message over tcp in local buffer - receive_msg() got pointer inside tcp stream as rcv buffer, linking it to msg->buf, but there are places where the content of msg->buf is changed (topoh, msg_apply_changes) which can result in corruption of tcp stream content - added a wrapper function receive_tcp_msg() to clone the content and have same behaviour as for udp or sctp - reported by Hugh Waite, FS#185 --- tcp_read.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 59 insertions(+), 3 deletions(-) diff --git a/tcp_read.c b/tcp_read.c index 1ba6cbb..c180301 100644 --- a/tcp_read.c +++ b/tcp_read.c @@ -848,6 +848,62 @@ skip: } +/** + * @brief wrapper around receive_msg() to clone the tcpbuf content + * + * When receiving over TCP, tcpbuf points inside the TCP stream buffer, but during + * processing of config, msg->buf content might be changed and may corrupt + * the content of the stream. Safer, make a clone of buf content in a local + * buffer and give that to receive_msg() to link to msg->buf + */ +int receive_tcp_msg(char* tcpbuf, unsigned int len, struct receive_info* rcv_info) +{ +#ifdef DYN_BUF + char *buf = NULL; +#else + static char *buf = NULL; + static unsigned int bsize = 0; +#endif + int blen; + + /* min buffer size is BUF_SIZE */ + blen = len; + if(blen < BUF_SIZE) + blen = BUF_SIZE; + +#ifdef DYN_BUF + buf=pkg_malloc(blen+1); + if (buf==0) { + LM_ERR("could not allocate receive buffer\n"); + return -1; + } +#else + /* allocate buffer when needed + * - no buffer yet + * - existing buffer too small (min size is BUF_SIZE - to accomodate most + * of SIP messages; expected larger for HTTP/XCAP) + * - existing buffer too large (e.g., we got a too big message in the past, + * let's free it) + * + * - also, use system memory, not to eat from PKG (same as static buffer + * from PKG pov) + */ + if(buf==NULL || bsize < blen || blen < bsize/2) { + if(buf!=NULL) + free(buf); + buf=malloc(blen+1); + if (buf==0) { + LM_ERR("could not allocate receive buffer\n"); + return -1; + } + bsize = blen; + } +#endif + + memcpy(buf, tcpbuf, len); + buf[len] = '\0'; + return receive_msg(buf, len, rcv_info); +} int tcp_read_req(struct tcp_connection* con, int* bytes_read, int* read_flags) { @@ -932,7 +988,7 @@ again: /* if we are here everything is nice and ok*/ resp=CONN_RELEASE; #ifdef EXTRA_DEBUG - DBG("calling receive_msg(%p, %d, )\n", + DBG("receiving msg(%p, %d, )\n", req->start, (int)(req->parsed-req->start)); #endif /* rcv.bind_address should always be !=0 */ @@ -970,12 +1026,12 @@ again: if (unlikely(req->state==H_HTTP11_CHUNK_FINISH)){ /* http chunked request */ req->body[req->content_len] = 0; - ret = receive_msg(req->start, + ret = receive_tcp_msg(req->start, req->body + req->content_len - req->start, &con->rcv); }else #endif - ret = receive_msg(req->start, req->parsed-req->start, + ret = receive_tcp_msg(req->start, req->parsed-req->start, &con->rcv); if (unlikely(ret < 0)) {