logread: add support for non-transparent-framing for Syslog over TCP

https://tools.ietf.org/html/rfc6587#section-3.4.2
the idea is to add \n or \0 as message trailer so it's easier
to find message end

v2: simplify, use \n by default, with optional \0

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>

diff --git a/log/logread.c b/log/logread.c
index 06dda62543928f71bbe918fc5a2a64dec0f7bcb2..94b96dba835854f94c4bd74d1e4019de7323c637 100644 (file)
--- a/log/logread.c
+++ b/log/logread.c
@@ -59,7 +59,7 @@ static struct uloop_timeout retry;
 static struct uloop_fd sender;
 static const char *log_file, *log_ip, *log_port, *log_prefix, *pid_file, *hostname;
 static int log_type = LOG_STDOUT;
-static int log_size, log_udp, log_follow = 0;
+static int log_size, log_udp, log_follow, log_trailer_null = 0;
 
 static const char* getcodetext(int value, CODE *codetable) {
        CODE *i;
@@ -151,8 +151,12 @@ static int log_notify(struct blob_attr *msg)
                strncat(buf, m, sizeof(buf) - strlen(buf) - 1);
                if (log_udp)
                        err = write(sender.fd, buf, strlen(buf));
-               else
-                       err = send(sender.fd, buf, strlen(buf), 0);
+               else {
+                       size_t buflen = strlen(buf);
+                       if (!log_trailer_null)
+                               buf[buflen] = '\n';
+                       err = send(sender.fd, buf, buflen + 1, 0);
+               }
 
                if (err < 0) {
                        syslog(LOG_INFO, "failed to send log data to %s:%s via %s\n",
@@ -190,6 +194,7 @@ static int usage(const char *prog)
                "    -P <prefix>        Prefix custom text to streamed messages\n"
                "    -f                 Follow log messages\n"
                "    -u                 Use UDP as the protocol\n"
+               "    -0                 Use \\0 instead of \\n as trailer when using TCP\n"
                "\n", prog);
        return 1;
 }
@@ -234,11 +239,14 @@ int main(int argc, char **argv)
 
        signal(SIGPIPE, SIG_IGN);
 
-       while ((ch = getopt(argc, argv, "ufcs:l:r:F:p:S:P:h:")) != -1) {
+       while ((ch = getopt(argc, argv, "u0fcs:l:r:F:p:S:P:h:")) != -1) {
                switch (ch) {
                case 'u':
                        log_udp = 1;
                        break;
+               case '0':
+                       log_trailer_null = 1;
+                       break;
                case 's':
                        ubus_socket = optarg;
                        break;