From ee00033298d347b3da13dfca0d18db1c897953e1 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Wed, 22 Jul 2020 15:00:59 +0200 Subject: [PATCH] Fix invitation URL generation when running in a network namespace. MeshLink could call getifaddrs() in the namespace of the caller instead of the MeshLink thread, causing the wrong addresses to be put in the inviation URL. --- src/meshlink.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/src/meshlink.c b/src/meshlink.c index d54fe30b..340b6041 100644 --- a/src/meshlink.c +++ b/src/meshlink.c @@ -344,6 +344,52 @@ static bool is_localaddr(sockaddr_t *sa) { } } +#ifdef HAVE_GETIFADDRS +struct getifaddrs_in_netns_params { + struct ifaddrs **ifa; + int netns; +}; + +#ifdef HAVE_SETNS +static void *getifaddrs_in_netns_thread(void *arg) { + struct getifaddrs_in_netns_params *params = arg; + + if(setns(params->netns, CLONE_NEWNET) == -1) { + meshlink_errno = MESHLINK_EINVAL; + return NULL; + } + + if(getifaddrs(params->ifa) != 0) { + *params->ifa = NULL; + } + + return NULL; +} +#endif // HAVE_SETNS + +static int getifaddrs_in_netns(struct ifaddrs **ifa, int netns) { + if(netns == -1) { + return getifaddrs(ifa); + } + +#ifdef HAVE_SETNS + struct getifaddrs_in_netns_params params = {ifa, netns}; + pthread_t thr; + + if(pthread_create(&thr, NULL, getifaddrs_in_netns_thread, ¶ms) == 0) { + if(pthread_join(thr, NULL) != 0) { + abort(); + } + } + + return *params.ifa ? 0 : -1; +#else + return -1; +#endif // HAVE_SETNS + +} +#endif + char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family) { (void)mesh; @@ -361,7 +407,7 @@ char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family) if(!success) { struct ifaddrs *ifa = NULL; - getifaddrs(&ifa); + getifaddrs_in_netns(&ifa, mesh->netns); for(struct ifaddrs *ifap = ifa; ifap; ifap = ifap->ifa_next) { sockaddr_t *sa = (sockaddr_t *)ifap->ifa_addr; -- 2.39.2