Fixes mixed-up messages on netlink socket (e366625c) · Commits · 戴 / Bird

sysdep/linux/netlink/netlink.c

+34 −19

Original line number	Diff line number	Diff line
		@@ -38,8 +38,14 @@
		* Synchronous Netlink interface
		*/

		static int nl_sync_fd = -1; /* Unix socket for synchronous netlink actions */
		static u32 nl_sync_seq; /* Sequence number of last request sent */
		struct nl_sock
		{
		int fd;
		u32 seq;
		};

		static struct nl_sock nl_scan = {-1, 0}; /* Netlink socket for synchronous scan */
		static struct nl_sock nl_req = {-1, 0}; /* Netlink socket for requests */

		static byte nl_rx_buffer; / Receive buffer */
		#define NL_RX_SIZE 8192
		@@ -48,28 +54,37 @@ static struct nlmsghdr nl_last_hdr; / Recently received packet */
		static unsigned int nl_last_size;

		static void
		nl_open(void)
		nl_open_sock(struct nl_sock *nl)
		{
		if (nl_sync_fd < 0)
		if (nl->fd < 0)
		{
		nl_sync_fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
		if (nl_sync_fd < 0)
		nl->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
		if (nl->fd < 0)
		die("Unable to open rtnetlink socket: %m");
		nl_sync_seq = now;
		nl_rx_buffer = xmalloc(NL_RX_SIZE);
		nl->seq = now;
		}
		}

		static void
		nl_open(void)
		{
		nl_open_sock(&nl_scan);
		nl_open_sock(&nl_req);

		if (nl_rx_buffer == NULL)
		nl_rx_buffer = xmalloc(NL_RX_SIZE);
		}

		static void
		nl_send(struct nlmsghdr *nh)
		nl_send(struct nl_sock nl, struct nlmsghdr nh)
		{
		struct sockaddr_nl sa;

		memset(&sa, 0, sizeof(sa));
		sa.nl_family = AF_NETLINK;
		nh->nlmsg_pid = 0;
		nh->nlmsg_seq = ++nl_sync_seq;
		if (sendto(nl_sync_fd, nh, nh->nlmsg_len, 0, (struct sockaddr *)&sa, sizeof(sa)) < 0)
		nh->nlmsg_seq = ++(nl->seq);
		if (sendto(nl->fd, nh, nh->nlmsg_len, 0, (struct sockaddr *)&sa, sizeof(sa)) < 0)
		die("rtnetlink sendto: %m");
		nl_last_hdr = NULL;
		}
		@@ -85,11 +100,11 @@ nl_request_dump(int cmd)
		req.nh.nlmsg_len = sizeof(req);
		req.nh.nlmsg_flags = NLM_F_REQUEST \| NLM_F_DUMP;
		req.g.rtgen_family = BIRD_PF;
		nl_send(&req.nh);
		nl_send(&nl_scan, &req.nh);
		}

		static struct nlmsghdr *
		nl_get_reply(void)
		nl_get_reply(struct nl_sock *nl)
		{
		for(;;)
		{
		@@ -98,7 +113,7 @@ nl_get_reply(void)
		struct iovec iov = { nl_rx_buffer, NL_RX_SIZE };
		struct sockaddr_nl sa;
		struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
		int x = recvmsg(nl_sync_fd, &m, 0);
		int x = recvmsg(nl->fd, &m, 0);
		if (x < 0)
		die("nl_get_reply: %m");
		if (sa.nl_pid) /* It isn't from the kernel */
		@@ -115,10 +130,10 @@ nl_get_reply(void)
		{
		struct nlmsghdr *h = nl_last_hdr;
		nl_last_hdr = NLMSG_NEXT(h, nl_last_size);
		if (h->nlmsg_seq != nl_sync_seq)
		if (h->nlmsg_seq != nl->seq)
		{
		log(L_WARN "nl_get_reply: Ignoring out of sequence netlink packet (%x != %x)",
		h->nlmsg_seq, nl_sync_seq);
		h->nlmsg_seq, nl->seq);
		continue;
		}
		return h;
		@@ -152,7 +167,7 @@ nl_error(struct nlmsghdr *h)
		static struct nlmsghdr *
		nl_get_scan(void)
		{
		struct nlmsghdr *h = nl_get_reply();
		struct nlmsghdr *h = nl_get_reply(&nl_scan);

		if (h->nlmsg_type == NLMSG_DONE)
		return NULL;
		@@ -169,10 +184,10 @@ nl_exchange(struct nlmsghdr *pkt)
		{
		struct nlmsghdr *h;

		nl_send(pkt);
		nl_send(&nl_req, pkt);
		for(;;)
		{
		h = nl_get_reply();
		h = nl_get_reply(&nl_req);
		if (h->nlmsg_type == NLMSG_ERROR)
		break;
		log(L_WARN "nl_exchange: Unexpected reply received");

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