* [FFmpeg-devel] [PATCH v2.1 1/2] configure: Add test_ioctl and test for SIOCGIFINDEX
2025-08-08 7:27 [FFmpeg-devel] [PATCH v2.1 0/2] Select output interfaces for ipv6 multicast Peter Enderborg
@ 2025-08-08 7:27 ` Peter Enderborg
2025-08-08 7:27 ` [FFmpeg-devel] [PATCH v2.1 2/2] avformat/udp: Select output interfaces for ipv6 multicast Peter Enderborg
1 sibling, 0 replies; 3+ messages in thread
From: Peter Enderborg @ 2025-08-08 7:27 UTC (permalink / raw)
To: ffmpeg-devel, luca.abeni; +Cc: Peter Enderborg
Adds a generic ioctl tester and a specific test SIOCGIFINDEX
that sets ioctl_gifindex. It is a network specific feature
and the tests are run only in network context.
Signed-off-by: Peter Enderborg <peterend@axis.com>
---
configure | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/configure b/configure
index 712ed947ff..9c9de9f525 100755
--- a/configure
+++ b/configure
@@ -1279,6 +1279,20 @@ int x;
EOF
}
+test_ioctl(){
+ log test_ioctl "$@"
+ ctl=$1
+ shift 1
+ test_cc "$@" <<EOF
+#include <stddef.h>
+#include <sys/ioctl.h>
+int f;
+void x(){
+ioctl(f, $ctl, NULL);
+}
+EOF
+}
+
check_cflags(){
log check_cflags "$@"
test_cflags "$@" && add_cflags "$@"
@@ -2536,6 +2550,7 @@ HAVE_LIST="
$TOOLCHAIN_FEATURES
$TYPES_LIST
gzip
+ ioctl_gifindex
ioctl_posix
libdrm_getfb2
makeinfo
@@ -2668,6 +2683,7 @@ CONFIG_EXTRA="
vvc_sei
wma_freqs
wmv2dsp
+
"
CMDLINE_SELECT="
@@ -6026,6 +6042,7 @@ case $target_os in
linux)
enable section_data_rel_ro
enabled_any arm aarch64 && enable_weak linux_perf
+
;;
irix*)
target_os=irix
@@ -6631,6 +6648,7 @@ if ! disabled network; then
else
disable network
fi
+ test_ioctl SIOCGIFINDEX && enable ioctl_gifindex
fi
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
--
2.34.1
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^ permalink raw reply [flat|nested] 3+ messages in thread* [FFmpeg-devel] [PATCH v2.1 2/2] avformat/udp: Select output interfaces for ipv6 multicast
2025-08-08 7:27 [FFmpeg-devel] [PATCH v2.1 0/2] Select output interfaces for ipv6 multicast Peter Enderborg
2025-08-08 7:27 ` [FFmpeg-devel] [PATCH v2.1 1/2] configure: Add test_ioctl and test for SIOCGIFINDEX Peter Enderborg
@ 2025-08-08 7:27 ` Peter Enderborg
1 sibling, 0 replies; 3+ messages in thread
From: Peter Enderborg @ 2025-08-08 7:27 UTC (permalink / raw)
To: ffmpeg-devel, luca.abeni; +Cc: Peter Enderborg
This fixes two old TODO's in ipv6 multicast handling.
If the system as SIOCGIFINDEX ioctl a helper function to iterate over
all interfaces added to join the multicast group on interface if approperite.
The default value is IN6ADDR_ANY (::) and it then joins all interfaces
that are up and have multicast support. Local address can be
specified and then it join ALL interfaces that use that specific
local address.
Limitations (TODO's)
Handling when network configuration is changed. if up/down etc.
Signed-off-by: Peter Enderborg <peterend@axis.com>
---
libavformat/udp.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 96 insertions(+), 2 deletions(-)
diff --git a/libavformat/udp.c b/libavformat/udp.c
index 84f9d3e62e..a0482c122f 100644
--- a/libavformat/udp.c
+++ b/libavformat/udp.c
@@ -68,6 +68,13 @@
#include "libavutil/thread.h"
#endif
+#if HAVE_STRUCT_IPV6_MREQ && HAVE_IOCTL_GIFINDEX && defined(IPPROTO_IPV6)
+#include <sys/types.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <ifaddrs.h>
+#endif
+
#ifndef IPV6_ADD_MEMBERSHIP
#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
@@ -205,6 +212,79 @@ static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
return 0;
}
+#if HAVE_STRUCT_IPV6_MREQ && HAVE_IOCTL_GIFINDEX && defined(IPPROTO_IPV6)
+static int udp_ipv6_multicast_iterate(int sockfd, struct sockaddr_in6 *addr,
+ struct sockaddr_in6 *local_addr, int mop, void *logctx)
+{
+ struct in6_addr anyipv6 = IN6ADDR_ANY_INIT;
+ struct ifaddrs *ifal=NULL,*ife=NULL;
+ int iindex_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
+ int membership_changed = 0;
+
+ if (iindex_fd >= 0 && !getifaddrs(&ifal)) {
+ for(ife=ifal; ife!=NULL; ife=ife->ifa_next) {
+ if (ife->ifa_addr &&
+ (ife->ifa_addr->sa_family == AF_INET6) &&
+ (ife->ifa_flags & IFF_MULTICAST) &&
+ (ife->ifa_flags & IFF_UP)) {
+ if ((!memcmp(&local_addr->sin6_addr, &anyipv6, sizeof(struct in6_addr))) ||
+ (!memcmp(&local_addr->sin6_addr, &((struct sockaddr_in6 *)ife->ifa_addr)->sin6_addr, sizeof(struct in6_addr)))) {
+ struct ifreq if_req;
+ strncpy(if_req.ifr_name, ife->ifa_name, IFNAMSIZ);
+ if (ioctl(iindex_fd, SIOCGIFINDEX, &if_req) != -1) {
+ struct ipv6_mreq mreq6;
+ memcpy(&mreq6.ipv6mr_multiaddr, &addr->sin6_addr, sizeof(struct in6_addr));
+ mreq6.ipv6mr_interface = if_req.ifr_ifindex;
+ switch (mop) {
+ case IPV6_JOIN_GROUP:
+ if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) == 0) {
+ membership_changed = 1;
+ } else {
+ /* Subscribe for all ipv6 addresses belong to a
+ interface.It can generate EADDRINUSE but
+ is accaptable. */
+ if (errno != EADDRINUSE) {
+ ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP)");
+ goto error;
+ }
+ }
+ break;
+ case IPV6_LEAVE_GROUP:
+ if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) == 0) {
+ membership_changed = 1;
+ } else {
+ /* Unsubscribe for all ipv6 addresses belong to a
+ interface. Ignore EADDRNOTAVAIL. */
+ if (errno != EADDRNOTAVAIL) {
+ ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP)");
+ goto error;
+ }
+ }
+ break;
+ default:
+ av_log(logctx, AV_LOG_ERROR, "unknown multicast operation\n");
+ goto error;
+ }
+ }
+ }
+ }
+ }
+ }
+ freeifaddrs(ifal);
+ close(iindex_fd);
+
+ if (!membership_changed) {
+ av_log(logctx, AV_LOG_ERROR, "no valid interfaces found\n");
+ return AVERROR(EINVAL);
+ }
+ return 0;
+error:
+ freeifaddrs(ifal);
+ close(iindex_fd);
+ av_log(logctx, AV_LOG_ERROR, "udp_ipv6_multicast_iterate failed\n");
+ return AVERROR(EINVAL);
+}
+#endif
static int udp_join_multicast_group(int sockfd, struct sockaddr *addr,
struct sockaddr *local_addr, void *logctx)
@@ -226,15 +306,22 @@ static int udp_join_multicast_group(int sockfd, struct sockaddr *addr,
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
if (addr->sa_family == AF_INET6) {
+#if HAVE_IOCTL_GIFINDEX
+ return udp_ipv6_multicast_iterate(sockfd,
+ (struct sockaddr_in6 *)addr,
+ (struct sockaddr_in6 *)local_addr,
+ IPV6_JOIN_GROUP,
+ logctx);
+#else
struct ipv6_mreq mreq6;
memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
- //TODO: Interface index should be looked up from local_addr
mreq6.ipv6mr_interface = 0;
if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP)");
return ff_neterrno();
}
+#endif
}
#endif
return 0;
@@ -260,15 +347,22 @@ static int udp_leave_multicast_group(int sockfd, struct sockaddr *addr,
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
if (addr->sa_family == AF_INET6) {
+#if HAVE_IOCTL_GIFINDEX
+ return udp_ipv6_multicast_iterate(sockfd,
+ (struct sockaddr_in6 *)addr,
+ (struct sockaddr_in6 *)local_addr,
+ IPV6_LEAVE_GROUP,
+ logctx);
+#else
struct ipv6_mreq mreq6;
memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
- //TODO: Interface index should be looked up from local_addr
mreq6.ipv6mr_interface = 0;
if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP)");
return -1;
}
+#endif
}
#endif
return 0;
--
2.34.1
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^ permalink raw reply [flat|nested] 3+ messages in thread