http: response body often missing after specific request

This patch works around a problem with the HTTP body
being dropped from the response to a specific client
and under specific circumstances:

a) Client request comes from node.js user agent
   "Shred" via use of swagger-client library.

b) Asterisk and Client are *not* on the same
   host or TCP/IP stack

In testing this problem, it has been determined that
the write of the HTTP body is lost, even if the data
is written using low level write function.  The only
solution found is to instruct the TCP stack with the
shutdown function to flush the last write and finish
the transmission.  See review for more details.

ASTERISK-23548 #close
(closes issue ASTERISK-23548)
Reported by: Sam Galarneau
Review: https://reviewboard.asterisk.org/r/3402/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@411462 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/http.c b/main/http.c
index 22d584f9a4e60eeb559da55e85046e59c3849b11..1770dd30ac5b662dbd5daafbdc01a0463ebd0ec5 100644 (file)
--- a/main/http.c
+++ b/main/http.c
@@ -434,7 +434,9 @@ void ast_http_send(struct ast_tcptls_session_instance *ser,
        /* send content */
        if (method != AST_HTTP_HEAD || status_code >= 400) {
                if (out) {
-                       fprintf(ser->f, "%s", ast_str_buffer(out));
+                       if (fwrite(ast_str_buffer(out), content_length, 1, ser->f) != 1) {
+                               ast_log(LOG_ERROR, "fwrite() failed: %s\n", strerror(errno));
+                       }
                }
 
                if (fd) {
@@ -456,8 +458,7 @@ void ast_http_send(struct ast_tcptls_session_instance *ser,
                ast_free(out);
        }
 
-       fclose(ser->f);
-       ser->f = 0;
+       ast_tcptls_close_session_file(ser);
        return;
 }
 

diff --git a/main/manager.c b/main/manager.c
index aa8a99ed11841429e2d9c49370c00d6163066d27..557353b1231ec7ed17e724e4864543ecaccc1c5e 100644 (file)
--- a/main/manager.c
+++ b/main/manager.c
@@ -1353,6 +1353,15 @@ static void session_destructor(void *obj)
        }
 
        if (session->f != NULL) {
+               /*
+                * Issuing shutdown() is necessary here to avoid a race
+                * condition where the last data written may not appear
+                * in the the TCP stream.  See ASTERISK-23548
+               */
+               fflush(session->f);
+               if (session->fd != -1) {
+                       shutdown(session->fd, SHUT_RDWR);
+               }
                fclose(session->f);
        }
        if (eqe) {
@@ -5913,12 +5922,21 @@ static void process_output(struct mansession *s, struct ast_str **out, struct as
        }
 
        if (s->f) {
+               /*
+                * Issuing shutdown() is necessary here to avoid a race
+                * condition where the last data written may not appear
+                * in the the TCP stream.  See ASTERISK-23548
+               */
+               if (s->fd != -1) {
+                       shutdown(s->fd, SHUT_RDWR);
+               }
                if (fclose(s->f)) {
                        ast_log(LOG_ERROR, "fclose() failed: %s\n", strerror(errno));
                }
                s->f = NULL;
                s->fd = -1;
        } else if (s->fd != -1) {
+               shutdown(s->fd, SHUT_RDWR);
                if (close(s->fd)) {
                        ast_log(LOG_ERROR, "close() failed: %s\n", strerror(errno));
                }

diff --git a/main/tcptls.c b/main/tcptls.c
index 47041fea860bfbd6540fcb8d7750c7e3f4703b71..c6c84bcffa0294de83f541e08467d36266c9b8f4 100644 (file)
--- a/main/tcptls.c
+++ b/main/tcptls.c
@@ -612,12 +612,22 @@ error:
 void ast_tcptls_close_session_file(struct ast_tcptls_session_instance *tcptls_session)
 {
        if (tcptls_session->f) {
+               /*
+                * Issuing shutdown() is necessary here to avoid a race
+                * condition where the last data written may not appear
+                * in the TCP stream.  See ASTERISK-23548
+               */
+               fflush(tcptls_session->f);
+               if (tcptls_session->fd != -1) {
+                       shutdown(tcptls_session->fd, SHUT_RDWR);
+               }
                if (fclose(tcptls_session->f)) {
                        ast_log(LOG_ERROR, "fclose() failed: %s\n", strerror(errno));
                }
                tcptls_session->f = NULL;
                tcptls_session->fd = -1;
        } else if (tcptls_session->fd != -1) {
+               shutdown(tcptls_session->fd, SHUT_RDWR);
                if (close(tcptls_session->fd)) {
                        ast_log(LOG_ERROR, "close() failed: %s\n", strerror(errno));
                }