PR #23406 opened by Thomas Devoogdt (ThomasDevoogdt)
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23406
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23406.patch
When ffplay exits via SIGTERM/Ctrl-C, the AVFormatContext interrupt
callback is set. The RTSP demuxer skipped TEARDOWN entirely, leaving
the server session alive (~10 s), which caused "453 Not Enough
Bandwidth" on immediate reconnect.
Fix the problem at every layer it can occur:
fftools/ffplay: make sigterm_handler() set a flag instead of calling
exit() directly. The main event loop checks the flag and routes
through do_exit() -> avformat_close_input() so that TEARDOWN is
reached during normal shutdown.
avformat/rtspdec: in rtsp_read_close(), replace the user interrupt
callback with a 500 ms deadline callback on both the TLS URLContext
and its TCP child before sending TEARDOWN. Without patching the TCP
child, GnuTLS/OpenSSL push callbacks receive AVERROR_EXIT from the
TCP write and previously returned 0 ("sent 0 bytes, try again"),
causing an infinite busy-spin. Switch to ff_rtsp_send_cmd() (blocking)
instead of ff_rtsp_send_cmd_async() so the client waits for the
server's 200 OK before closing, guaranteeing the session is freed.
avformat/tls: add ff_tls_get_underlying() to expose the TCP/UDP child
URLContext of a TLS context through a proper API, avoiding direct
access to private priv_data.
avformat/tls_gnutls, tls_openssl: fix the AVERROR_EXIT -> 0 mapping
in the TLS push callbacks. Returning 0 on interrupt signals "sent 0
bytes" to the TLS library and causes a busy-spin; use EINTR / hard
error instead.
Fixes: #23405
Signed-off-by: Thomas Devoogdt <[email protected]>
# Summary of changes
Briefly describe what this PR does and why.
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>From 236cba060fd6120ec804ace01df0b1cf7a19b138 Mon Sep 17 00:00:00 2001
From: Thomas Devoogdt <[email protected]>
Date: Mon, 8 Jun 2026 10:58:52 +0200
Subject: [PATCH] avformat/rtspdec: send TEARDOWN on close despite user
interrupt
When ffplay exits via SIGTERM/Ctrl-C, the AVFormatContext interrupt
callback is set. The RTSP demuxer skipped TEARDOWN entirely, leaving
the server session alive (~10 s), which caused "453 Not Enough
Bandwidth" on immediate reconnect.
Fix the problem at every layer it can occur:
fftools/ffplay: make sigterm_handler() set a flag instead of calling
exit() directly. The main event loop checks the flag and routes
through do_exit() -> avformat_close_input() so that TEARDOWN is
reached during normal shutdown.
avformat/rtspdec: in rtsp_read_close(), replace the user interrupt
callback with a 500 ms deadline callback on both the TLS URLContext
and its TCP child before sending TEARDOWN. Without patching the TCP
child, GnuTLS/OpenSSL push callbacks receive AVERROR_EXIT from the
TCP write and previously returned 0 ("sent 0 bytes, try again"),
causing an infinite busy-spin. Switch to ff_rtsp_send_cmd() (blocking)
instead of ff_rtsp_send_cmd_async() so the client waits for the
server's 200 OK before closing, guaranteeing the session is freed.
avformat/tls: add ff_tls_get_underlying() to expose the TCP/UDP child
URLContext of a TLS context through a proper API, avoiding direct
access to private priv_data.
avformat/tls_gnutls, tls_openssl: fix the AVERROR_EXIT -> 0 mapping
in the TLS push callbacks. Returning 0 on interrupt signals "sent 0
bytes" to the TLS library and causes a busy-spin; use EINTR / hard
error instead.
Fixes: #23405
Signed-off-by: Thomas Devoogdt <[email protected]>
---
fftools/ffplay.c | 6 +++++-
libavformat/rtspdec.c | 34 ++++++++++++++++++++++++++++++++--
libavformat/tls.c | 7 +++++++
libavformat/tls.h | 5 +++++
libavformat/tls_gnutls.c | 7 ++++---
libavformat/tls_openssl.c | 7 ++++---
6 files changed, 57 insertions(+), 9 deletions(-)
diff --git a/fftools/ffplay.c b/fftools/ffplay.c
index 28a83e079f..46ba85212a 100644
--- a/fftools/ffplay.c
+++ b/fftools/ffplay.c
@@ -361,6 +361,8 @@ static int64_t audio_callback_time;
#define FF_QUIT_EVENT (SDL_USEREVENT + 2)
+static volatile sig_atomic_t request_quit;
+
static SDL_Window *window;
static SDL_Renderer *renderer;
static SDL_RendererInfo renderer_info = {0};
@@ -1372,7 +1374,7 @@ static void do_exit(VideoState *is)
static void sigterm_handler(int sig)
{
- exit(123);
+ request_quit = 1;
}
static void set_default_window_size(int width, int height, AVRational sar)
@@ -3403,6 +3405,8 @@ static void refresh_loop_wait_event(VideoState *is,
SDL_Event *event) {
double remaining_time = 0.0;
SDL_PumpEvents();
while (!SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT,
SDL_LASTEVENT)) {
+ if (request_quit)
+ do_exit(is);
if (!cursor_hidden && av_gettime_relative() - cursor_last_shown >
CURSOR_HIDE_DELAY) {
SDL_ShowCursor(0);
cursor_hidden = 1;
diff --git a/libavformat/rtspdec.c b/libavformat/rtspdec.c
index e0bdf9d4ac..32c38738c4 100644
--- a/libavformat/rtspdec.c
+++ b/libavformat/rtspdec.c
@@ -59,12 +59,42 @@ static const struct RTSPStatusMessage {
{ 0, "NULL" }
};
+static int rtsp_teardown_interrupt_cb(void *opaque)
+{
+ return av_gettime_relative() >= *(int64_t *)opaque;
+}
+
static int rtsp_read_close(AVFormatContext *s)
{
RTSPState *rt = s->priv_data;
- if (!(rt->rtsp_flags & RTSP_FLAG_LISTEN))
- ff_rtsp_send_cmd_async(s, "TEARDOWN", rt->control_uri, NULL);
+ if (!(rt->rtsp_flags & RTSP_FLAG_LISTEN)) {
+ /* Replace the interrupt callback with a short timeout so TEARDOWN
+ * can go out despite a pending Ctrl-C. For RTSPS both the TLS
+ * URLContext and its TCP child need patching (each holds an
+ * independent copy of the interrupt callback). */
+ int64_t deadline = av_gettime_relative() + 500000LL; /* 500 ms */
+ AVIOInterruptCB timeout_cb = { rtsp_teardown_interrupt_cb, &deadline };
+ URLContext *tcp_child = NULL;
+ AVIOInterruptCB saved_tls = { NULL, NULL };
+ AVIOInterruptCB saved_tcp = { NULL, NULL };
+
+ if (rt->rtsp_hd_out) {
+ saved_tls = rt->rtsp_hd_out->interrupt_callback;
+ rt->rtsp_hd_out->interrupt_callback = timeout_cb;
+ /* For TLS, also patch the underlying TCP child. */
+ tcp_child = ff_tls_get_underlying(rt->rtsp_hd_out);
+ if (tcp_child) {
+ saved_tcp = tcp_child->interrupt_callback;
+ tcp_child->interrupt_callback = timeout_cb;
+ }
+ }
+ ff_rtsp_send_cmd(s, "TEARDOWN", rt->control_uri, NULL,
&(RTSPMessageHeader){0}, NULL);
+ if (rt->rtsp_hd_out)
+ rt->rtsp_hd_out->interrupt_callback = saved_tls;
+ if (tcp_child)
+ tcp_child->interrupt_callback = saved_tcp;
+ }
ff_rtsp_close_streams(s);
ff_rtsp_close_connections(s);
diff --git a/libavformat/tls.c b/libavformat/tls.c
index 3eab305f56..f027076b78 100644
--- a/libavformat/tls.c
+++ b/libavformat/tls.c
@@ -122,6 +122,13 @@ int ff_tls_open_underlying(TLSShared *c, URLContext
*parent, const char *uri, AV
return ret;
}
+URLContext *ff_tls_get_underlying(URLContext *h)
+{
+ if (!h || !h->prot || strcmp(h->prot->name, "tls") != 0)
+ return NULL;
+ return ((TLSShared *)h->priv_data)->tcp;
+}
+
/**
* Read all data from the given URL url and store it in the given buffer bp.
*/
diff --git a/libavformat/tls.h b/libavformat/tls.h
index 971ae5c7a5..5f14bd5fe4 100644
--- a/libavformat/tls.h
+++ b/libavformat/tls.h
@@ -119,6 +119,11 @@ int ff_tls_parse_host(TLSShared *s, char *hostname, int
hostname_size, int *port
int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri,
AVDictionary **options);
+/**
+ * Return the underlying TCP/UDP URLContext of a TLS URLContext, or NULL.
+ */
+URLContext *ff_tls_get_underlying(URLContext *h);
+
int ff_url_read_all(const char *url, AVBPrint *bp);
int ff_tls_set_external_socket(URLContext *h, URLContext *sock);
diff --git a/libavformat/tls_gnutls.c b/libavformat/tls_gnutls.c
index aedbc66e56..c40c2cd7f3 100644
--- a/libavformat/tls_gnutls.c
+++ b/libavformat/tls_gnutls.c
@@ -475,9 +475,10 @@ static ssize_t gnutls_url_push(gnutls_transport_ptr_t
transport,
int ret = ffurl_write(uc, buf, len);
if (ret >= 0)
return ret;
- if (ret == AVERROR_EXIT)
- return 0;
- if (ret == AVERROR(EAGAIN)) {
+ if (ret == AVERROR_EXIT) {
+ /* Use EINTR, not 0: returning 0 would cause GnuTLS to busy-spin. */
+ errno = EINTR;
+ } else if (ret == AVERROR(EAGAIN)) {
errno = EAGAIN;
} else {
errno = EIO;
diff --git a/libavformat/tls_openssl.c b/libavformat/tls_openssl.c
index 7c1289c595..81540cfeeb 100644
--- a/libavformat/tls_openssl.c
+++ b/libavformat/tls_openssl.c
@@ -570,9 +570,10 @@ static int url_bio_bwrite(BIO *b, const char *buf, int len)
if (ret >= 0)
return ret;
BIO_clear_retry_flags(b);
- if (ret == AVERROR_EXIT)
- return 0;
- if (ret == AVERROR(EAGAIN))
+ if (ret == AVERROR_EXIT) {
+ /* Don't return 0: that signals success and silently drops the data. */
+ c->io_err = ret;
+ } else if (ret == AVERROR(EAGAIN))
BIO_set_retry_write(b);
else
c->io_err = ret;
--
2.52.0
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