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zebra: netlink cleanup
* Split zebra's netlink code into smaller functions to be more generic. Signed-off-by: Jakub Urbańczyk <xthaid@gmail.com>
This commit is contained in:
Jakub Urbańczyk
parent
5b76e76515
commit
ae6138bfd8
@ -697,6 +697,204 @@ static void netlink_parse_extended_ack(struct nlmsghdr *h)
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}
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}
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/*
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* netlink_send_msg - send a netlink message of a certain size.
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*
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* Returns -1 on error. Otherwise, it returns the number of bytes sent.
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*/
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static int netlink_send_msg(const struct nlsock *nl, void *buf, size_t buflen)
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{
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struct sockaddr_nl snl;
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struct iovec iov;
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struct msghdr msg;
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int status, save_errno = 0;
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memset(&snl, 0, sizeof(snl));
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memset(&iov, 0, sizeof(iov));
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memset(&msg, 0, sizeof(msg));
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iov.iov_base = buf;
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iov.iov_len = buflen;
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msg.msg_name = (void *)&snl;
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msg.msg_namelen = sizeof(snl);
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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snl.nl_family = AF_NETLINK;
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/* Send message to netlink interface. */
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frr_with_privs(&zserv_privs) {
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status = sendmsg(nl->sock, &msg, 0);
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save_errno = errno;
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}
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if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_SEND) {
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zlog_debug("%s: >> netlink message dump [sent]", __func__);
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zlog_hexdump(buf, buflen);
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}
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if (status < 0) {
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flog_err_sys(EC_LIB_SOCKET, "%s error: %s", __func__,
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safe_strerror(save_errno));
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return -1;
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}
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return status;
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}
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/*
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* netlink_recv_msg - receive a netlink message.
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*
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* Returns -1 on error, 0 if read would block or the number of bytes received.
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*/
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static int netlink_recv_msg(const struct nlsock *nl, struct msghdr msg,
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void *buf, size_t buflen)
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{
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struct iovec iov;
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int status;
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iov.iov_base = buf;
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iov.iov_len = buflen;
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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do {
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#if defined(HANDLE_NETLINK_FUZZING)
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/* Check if reading and filename is set */
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if (netlink_read && '\0' != netlink_fuzz_file[0]) {
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zlog_debug("Reading netlink fuzz file");
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status = netlink_read_file(buf, netlink_fuzz_file);
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((struct sockaddr_nl *)msg.msg_name)->nl_pid = 0;
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} else {
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status = recvmsg(nl->sock, &msg, 0);
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}
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#else
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status = recvmsg(nl->sock, &msg, 0);
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#endif /* HANDLE_NETLINK_FUZZING */
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} while (status < 0 && errno == EINTR);
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if (status < 0) {
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if (errno == EWOULDBLOCK || errno == EAGAIN)
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return 0;
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flog_err(EC_ZEBRA_RECVMSG_OVERRUN, "%s recvmsg overrun: %s",
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nl->name, safe_strerror(errno));
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/*
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* In this case we are screwed. There is no good way to recover
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* zebra at this point.
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*/
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exit(-1);
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}
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if (status == 0) {
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flog_err_sys(EC_LIB_SOCKET, "%s EOF", nl->name);
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return -1;
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}
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if (msg.msg_namelen != sizeof(struct sockaddr_nl)) {
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flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
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"%s sender address length error: length %d", nl->name,
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msg.msg_namelen);
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return -1;
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}
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if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_RECV) {
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zlog_debug("%s: << netlink message dump [recv]", __func__);
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zlog_hexdump(buf, status);
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}
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#if defined(HANDLE_NETLINK_FUZZING)
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if (!netlink_read) {
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zlog_debug("Writing incoming netlink message");
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netlink_write_incoming(buf, status, netlink_file_counter++);
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}
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#endif /* HANDLE_NETLINK_FUZZING */
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return status;
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}
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/*
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* netlink_parse_error - parse a netlink error message
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*
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* Returns 1 if this message is acknowledgement, 0 if this error should be
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* ignored, -1 otherwise.
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*/
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static int netlink_parse_error(const struct nlsock *nl, struct nlmsghdr *h,
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const struct zebra_dplane_info *zns,
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bool startup)
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{
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struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
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int errnum = err->error;
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int msg_type = err->msg.nlmsg_type;
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if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
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flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
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"%s error: message truncated", nl->name);
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return -1;
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}
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/*
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* Parse the extended information before we actually handle it. At this
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* point in time we do not do anything other than report the issue.
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*/
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if (h->nlmsg_flags & NLM_F_ACK_TLVS)
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netlink_parse_extended_ack(h);
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/* If the error field is zero, then this is an ACK. */
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if (err->error == 0) {
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if (IS_ZEBRA_DEBUG_KERNEL) {
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zlog_debug("%s: %s ACK: type=%s(%u), seq=%u, pid=%u",
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__func__, nl->name,
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nl_msg_type_to_str(err->msg.nlmsg_type),
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err->msg.nlmsg_type, err->msg.nlmsg_seq,
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err->msg.nlmsg_pid);
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}
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return 1;
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}
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/* Deal with errors that occur because of races in link handling. */
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if (zns->is_cmd
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&& ((msg_type == RTM_DELROUTE
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&& (-errnum == ENODEV || -errnum == ESRCH))
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|| (msg_type == RTM_NEWROUTE
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&& (-errnum == ENETDOWN || -errnum == EEXIST)))) {
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if (IS_ZEBRA_DEBUG_KERNEL)
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zlog_debug("%s: error: %s type=%s(%u), seq=%u, pid=%u",
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nl->name, safe_strerror(-errnum),
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nl_msg_type_to_str(msg_type), msg_type,
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err->msg.nlmsg_seq, err->msg.nlmsg_pid);
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return 0;
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}
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/*
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* We see RTM_DELNEIGH when shutting down an interface with an IPv4
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* link-local. The kernel should have already deleted the neighbor so
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* do not log these as an error.
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*/
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if (msg_type == RTM_DELNEIGH
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|| (zns->is_cmd && msg_type == RTM_NEWROUTE
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&& (-errnum == ESRCH || -errnum == ENETUNREACH))) {
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/*
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* This is known to happen in some situations, don't log as
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* error.
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*/
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if (IS_ZEBRA_DEBUG_KERNEL)
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zlog_debug("%s error: %s, type=%s(%u), seq=%u, pid=%u",
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nl->name, safe_strerror(-errnum),
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nl_msg_type_to_str(msg_type), msg_type,
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err->msg.nlmsg_seq, err->msg.nlmsg_pid);
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} else {
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if ((msg_type != RTM_GETNEXTHOP) || !startup)
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flog_err(EC_ZEBRA_UNEXPECTED_MESSAGE,
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"%s error: %s, type=%s(%u), seq=%u, pid=%u",
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nl->name, safe_strerror(-errnum),
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nl_msg_type_to_str(msg_type), msg_type,
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err->msg.nlmsg_seq, err->msg.nlmsg_pid);
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}
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return -1;
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}
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/*
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* netlink_parse_info
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*
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@ -722,71 +920,19 @@ int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
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while (1) {
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char buf[NL_RCV_PKT_BUF_SIZE];
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struct iovec iov = {.iov_base = buf, .iov_len = sizeof(buf)};
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struct sockaddr_nl snl;
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struct msghdr msg = {.msg_name = (void *)&snl,
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.msg_namelen = sizeof(snl),
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.msg_iov = &iov,
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.msg_iovlen = 1};
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.msg_namelen = sizeof(snl)};
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struct nlmsghdr *h;
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if (count && read_in >= count)
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return 0;
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#if defined(HANDLE_NETLINK_FUZZING)
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/* Check if reading and filename is set */
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if (netlink_read && '\0' != netlink_fuzz_file[0]) {
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zlog_debug("Reading netlink fuzz file");
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status = netlink_read_file(buf, netlink_fuzz_file);
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snl.nl_pid = 0;
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} else {
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status = recvmsg(nl->sock, &msg, 0);
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}
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#else
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status = recvmsg(nl->sock, &msg, 0);
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#endif /* HANDLE_NETLINK_FUZZING */
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if (status < 0) {
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if (errno == EINTR)
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continue;
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if (errno == EWOULDBLOCK || errno == EAGAIN)
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break;
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flog_err(EC_ZEBRA_RECVMSG_OVERRUN,
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"%s recvmsg overrun: %s", nl->name,
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safe_strerror(errno));
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/*
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* In this case we are screwed.
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* There is no good way to
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* recover zebra at this point.
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*/
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exit(-1);
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continue;
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}
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if (status == 0) {
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flog_err_sys(EC_LIB_SOCKET, "%s EOF", nl->name);
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status = netlink_recv_msg(nl, msg, buf, sizeof(buf));
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if (status == -1)
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return -1;
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}
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if (msg.msg_namelen != sizeof(snl)) {
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flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
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"%s sender address length error: length %d",
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nl->name, msg.msg_namelen);
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return -1;
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}
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if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_RECV) {
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zlog_debug("%s: << netlink message dump [recv]",
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__func__);
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zlog_hexdump(buf, status);
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}
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#if defined(HANDLE_NETLINK_FUZZING)
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if (!netlink_read) {
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zlog_debug("Writing incoming netlink message");
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netlink_write_incoming(buf, status,
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netlink_file_counter++);
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}
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#endif /* HANDLE_NETLINK_FUZZING */
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else if (status == 0)
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break;
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read_in++;
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for (h = (struct nlmsghdr *)buf;
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@ -798,112 +944,14 @@ int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
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/* Error handling. */
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if (h->nlmsg_type == NLMSG_ERROR) {
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struct nlmsgerr *err =
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(struct nlmsgerr *)NLMSG_DATA(h);
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int errnum = err->error;
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int msg_type = err->msg.nlmsg_type;
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if (h->nlmsg_len
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< NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
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flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
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"%s error: message truncated",
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nl->name);
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return -1;
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}
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/*
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* Parse the extended information before
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* we actually handle it.
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* At this point in time we do not
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* do anything other than report the
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* issue.
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*/
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if (h->nlmsg_flags & NLM_F_ACK_TLVS)
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netlink_parse_extended_ack(h);
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/* If the error field is zero, then this is an
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* ACK */
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if (err->error == 0) {
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if (IS_ZEBRA_DEBUG_KERNEL) {
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zlog_debug(
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"%s: %s ACK: type=%s(%u), seq=%u, pid=%u",
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__func__, nl->name,
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nl_msg_type_to_str(
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err->msg.nlmsg_type),
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err->msg.nlmsg_type,
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err->msg.nlmsg_seq,
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err->msg.nlmsg_pid);
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}
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/* return if not a multipart message,
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* otherwise continue */
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int err = netlink_parse_error(nl, h, zns,
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startup);
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if (err == 1) {
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if (!(h->nlmsg_flags & NLM_F_MULTI))
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return 0;
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continue;
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}
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/* Deal with errors that occur because of races
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* in link handling */
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if (zns->is_cmd
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&& ((msg_type == RTM_DELROUTE
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&& (-errnum == ENODEV
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|| -errnum == ESRCH))
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|| (msg_type == RTM_NEWROUTE
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&& (-errnum == ENETDOWN
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|| -errnum == EEXIST)))) {
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if (IS_ZEBRA_DEBUG_KERNEL)
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zlog_debug(
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"%s: error: %s type=%s(%u), seq=%u, pid=%u",
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nl->name,
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safe_strerror(-errnum),
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nl_msg_type_to_str(
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msg_type),
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msg_type,
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err->msg.nlmsg_seq,
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err->msg.nlmsg_pid);
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return 0;
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}
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/* We see RTM_DELNEIGH when shutting down an
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* interface with an IPv4
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* link-local. The kernel should have already
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* deleted the neighbor
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* so do not log these as an error.
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*/
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if (msg_type == RTM_DELNEIGH
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|| (zns->is_cmd && msg_type == RTM_NEWROUTE
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&& (-errnum == ESRCH
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|| -errnum == ENETUNREACH))) {
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/* This is known to happen in some
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* situations, don't log
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* as error.
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*/
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if (IS_ZEBRA_DEBUG_KERNEL)
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zlog_debug(
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"%s error: %s, type=%s(%u), seq=%u, pid=%u",
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nl->name,
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safe_strerror(-errnum),
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nl_msg_type_to_str(
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msg_type),
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msg_type,
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err->msg.nlmsg_seq,
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err->msg.nlmsg_pid);
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} else {
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if ((msg_type != RTM_GETNEXTHOP)
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|| !startup)
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flog_err(
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EC_ZEBRA_UNEXPECTED_MESSAGE,
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"%s error: %s, type=%s(%u), seq=%u, pid=%u",
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nl->name,
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safe_strerror(-errnum),
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nl_msg_type_to_str(
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msg_type),
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msg_type,
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err->msg.nlmsg_seq,
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err->msg.nlmsg_pid);
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}
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return -1;
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} else
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return err;
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}
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/* OK we got netlink message. */
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@ -966,26 +1014,8 @@ int netlink_talk_info(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
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struct nlmsghdr *n,
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const struct zebra_dplane_info *dp_info, int startup)
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{
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int status = 0;
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struct sockaddr_nl snl;
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struct iovec iov;
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struct msghdr msg;
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int save_errno = 0;
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const struct nlsock *nl;
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memset(&snl, 0, sizeof(snl));
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memset(&iov, 0, sizeof(iov));
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memset(&msg, 0, sizeof(msg));
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iov.iov_base = n;
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iov.iov_len = n->nlmsg_len;
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msg.msg_name = (void *)&snl;
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msg.msg_namelen = sizeof(snl);
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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snl.nl_family = AF_NETLINK;
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nl = &(dp_info->nls);
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n->nlmsg_seq = nl->seq;
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n->nlmsg_pid = nl->snl.nl_pid;
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@ -997,22 +1027,8 @@ int netlink_talk_info(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
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n->nlmsg_type, n->nlmsg_len, n->nlmsg_seq,
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n->nlmsg_flags);
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/* Send message to netlink interface. */
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frr_with_privs(&zserv_privs) {
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status = sendmsg(nl->sock, &msg, 0);
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save_errno = errno;
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}
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if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_SEND) {
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zlog_debug("%s: >> netlink message dump [sent]", __func__);
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zlog_hexdump(n, n->nlmsg_len);
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}
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if (status < 0) {
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flog_err_sys(EC_LIB_SOCKET, "netlink_talk sendmsg() error: %s",
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safe_strerror(save_errno));
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if (netlink_send_msg(nl, n, n->nlmsg_len) < 0)
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return -1;
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}
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/*
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* Get reply from netlink socket.
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@ -1047,8 +1063,6 @@ int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
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*/
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int netlink_request(struct nlsock *nl, void *req)
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{
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int ret;
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struct sockaddr_nl snl;
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struct nlmsghdr *n = (struct nlmsghdr *)req;
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|
||||
/* Check netlink socket. */
|
||||
@ -1062,20 +1076,8 @@ int netlink_request(struct nlsock *nl, void *req)
|
||||
n->nlmsg_pid = nl->snl.nl_pid;
|
||||
n->nlmsg_seq = ++nl->seq;
|
||||
|
||||
memset(&snl, 0, sizeof(snl));
|
||||
snl.nl_family = AF_NETLINK;
|
||||
|
||||
/* Raise capabilities and send message, then lower capabilities. */
|
||||
frr_with_privs(&zserv_privs) {
|
||||
ret = sendto(nl->sock, req, n->nlmsg_len, 0,
|
||||
(struct sockaddr *)&snl, sizeof(snl));
|
||||
}
|
||||
|
||||
if (ret < 0) {
|
||||
zlog_err("%s sendto failed: %s", nl->name,
|
||||
safe_strerror(errno));
|
||||
if (netlink_send_msg(nl, req, n->nlmsg_len) < 0)
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user