MEDIUM: log: syslog TCP support on log forward section.

This patch re-introduce the "bind" statement on log forward
sections to handle syslog TCP listeners as defined in
rfc-6587.

As complement it introduce "maxconn", "backlog" and "timeout
client" statements to parameter those listeners.

doc/configuration.txt

@@ -2779,11 +2779,21 @@ haproxy will forward all received log messages to a log servers list.
 log-forward <name>
   Creates a new log forwarder proxy identified as <name>.
 
+backlog <conns>
+  Give hints to the system about the approximate listen backlog desired size
+  on connections accept.
+
+bind <addr> [param*]
+  Used to configure a stream log listener to receive messages to forward.
+  This supports for some of the "bind" parameters found in 5.1 paragraph.
+  Those listener support both "Octet Counting" and "Non-Transparent-Framing"
+  modes as defined in rfc-6587.
+
 dgram-bind <addr> [param*]
-  Used to configure a UDP log listener to receive messages to forward. Only UDP
+  Used to configure a datagram log listener to receive messages to forward.
-  listeners are allowed. Addresses must be in IPv4 or IPv6 form,followed by a
+  Addresses must be in IPv4 or IPv6 form,followed by a port. This supports
-  port. This supports for some of the "bind" parameters found in 5.1 paragraph
+  for some of the "bind" parameters found in 5.1 paragraph among which
-  among which "interface", "namespace" or "transparent", the other ones being
+  "interface", "namespace" or "transparent", the other ones being
   silently ignored as irrelevant for UDP/syslog case.
 
 log global
@@ -2812,7 +2822,8 @@ log <address> [len <length>] [format <format>] [sample <ranges>:<smp_size>]
         server mysyslogsrv 127.0.0.1:514 log-proto octet-count
 
     log-forward sylog-loadb
-        bind udp4@127.0.0.1:1514
+        dgram-bind 127.0.0.1:1514
+        bind 127.0.0.1:1514
         # all messages on stderr
         log global
         # all messages on local tcp syslog server
@@ -2823,6 +2834,13 @@ log <address> [len <length>] [format <format>] [sample <ranges>:<smp_size>]
         log 127.0.0.1:10003 sample 3:4 local0
         log 127.0.0.1:10004 sample 4:4 local0
 
+maxconn <conns>
+  Fix the maximum number of concurrent connections on a log forwarder.
+  10 is the default.
+
+timeout client <timeout>
+  Set the maximum inactivity time on the client side.
+
 4. Proxies
 ----------
 

src/log.c

@@ -3558,6 +3558,148 @@ out:
 	return;
 }
 
+/*
+ * IO Handler to handle message exchange with a syslog tcp client
+ */
+static void syslog_io_handler(struct appctx *appctx)
+{
+	static THREAD_LOCAL struct ist metadata[LOG_META_FIELDS];
+	struct stream_interface *si = appctx->owner;
+	struct stream *s = si_strm(si);
+	struct proxy *frontend = strm_fe(s);
+	struct listener *l = strm_li(s);
+	struct buffer *buf = get_trash_chunk();
+	int max_accept;
+	int to_skip;
+	int facility;
+	int level;
+	char *message;
+	size_t size;
+
+	max_accept = l->maxaccept ? l->maxaccept : 1;
+	while (co_data(si_oc(si))) {
+		char c;
+
+		if (max_accept <= 0)
+			goto missing_budget;
+		max_accept--;
+
+		to_skip = co_getchar(si_oc(si), &c);
+		if (!to_skip)
+			goto missing_data;
+		else if (to_skip < 0)
+			goto cli_abort;
+
+		if (c == '<') {
+			/* rfc-6587, Non-Transparent-Framing: messages separated by
+			 * a trailing LF or CR LF
+			 */
+			to_skip = co_getline(si_oc(si), buf->area, buf->size);
+			if (!to_skip)
+				goto missing_data;
+			else if (to_skip < 0)
+				goto cli_abort;
+
+			if (buf->area[to_skip - 1] != '\n')
+				goto parse_error;
+
+			buf->data = to_skip - 1;
+
+			/* according to rfc-6587, some devices adds CR before LF */
+			if (buf->data && buf->area[buf->data - 1] == '\r')
+				buf->data--;
+
+		}
+		else if ((unsigned char)(c - '1') <= 8) {
+			/* rfc-6587, Octet-Counting: message length in ASCII
+			 * (first digit can not be ZERO), followed by a space
+			 * and message length
+			 */
+			char *p = NULL;
+			int msglen;
+
+			to_skip = co_getword(si_oc(si), buf->area, buf->size, ' ');
+			if (!to_skip)
+				goto missing_data;
+			else if (to_skip < 0)
+				goto cli_abort;
+
+			if (buf->area[to_skip - 1] != ' ')
+				goto parse_error;
+
+			msglen = strtol(trash.area, &p, 10);
+			if (!msglen || p != &buf->area[to_skip - 1])
+				goto parse_error;
+
+			/* message seems too large */
+			if (msglen > buf->size)
+				goto parse_error;
+
+			msglen = co_getblk(si_oc(si), buf->area, msglen, to_skip);
+			if (!msglen)
+				goto missing_data;
+			else if (msglen < 0)
+				goto cli_abort;
+
+
+			buf->data = msglen;
+			to_skip += msglen;
+		}
+		else
+			goto parse_error;
+
+		co_skip(si_oc(si), to_skip);
+
+		/* update counters */
+		_HA_ATOMIC_ADD(&cum_log_messages, 1);
+		proxy_inc_fe_req_ctr(l, frontend);
+
+		parse_log_message(buf->area, buf->data, &level, &facility, metadata, &message, &size);
+
+		process_send_log(&frontend->logsrvs, level, facility, metadata, message, size);
+
+	}
+
+missing_data:
+	/* we need more data to read */
+	si_oc(si)->flags |= CF_READ_DONTWAIT;
+
+	return;
+
+missing_budget:
+	/* it may remain some stuff to do, let's retry later */
+	appctx_wakeup(appctx);
+
+	return;
+
+parse_error:
+	if (l->counters)
+		_HA_ATOMIC_ADD(&l->counters->failed_req, 1);
+	_HA_ATOMIC_ADD(&frontend->fe_counters.failed_req, 1);
+
+	goto close;
+
+cli_abort:
+	if (l->counters)
+		_HA_ATOMIC_ADD(&l->counters->cli_aborts, 1);
+	_HA_ATOMIC_ADD(&frontend->fe_counters.cli_aborts, 1);
+
+close:
+	si_shutw(si);
+	si_shutr(si);
+
+	si_ic(si)->flags |= CF_READ_NULL;
+
+	return;
+}
+
+static struct applet syslog_applet = {
+	.obj_type = OBJ_TYPE_APPLET,
+	.name = "<SYSLOG>", /* used for logging */
+	.fct = syslog_io_handler,
+	.release = NULL,
+};
+
 /*
  * Parse "log-forward" section and create corresponding sink buffer.
  *
@@ -3610,9 +3752,113 @@ int cfg_parse_log_forward(const char *file, int linenum, char **args, int kwm)
 		px->conf.file = strdup(file);
 		px->conf.line = linenum;
 		px->mode = PR_MODE_SYSLOG;
+		px->last_change = now.tv_sec;
+		px->cap = PR_CAP_FE;
+		px->maxconn = 10;
+		px->timeout.client = TICK_ETERNITY;
+		px->accept = frontend_accept;
+		px->default_target = &syslog_applet.obj_type;
 		px->id = strdup(args[1]);
 
 	}
+	else if (!strcmp(args[0], "maxconn")) {  /* maxconn */
+		if (warnifnotcap(cfg_log_forward, PR_CAP_FE, file, linenum, args[0], " Maybe you want 'fullconn' instead ?"))
+			err_code |= ERR_WARN;
+
+		if (*(args[1]) == 0) {
+			ha_alert("parsing [%s:%d] : '%s' expects an integer argument.\n", file, linenum, args[0]);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+		cfg_log_forward->maxconn = atol(args[1]);
+		if (alertif_too_many_args(1, file, linenum, args, &err_code))
+			goto out;
+	}
+	else if (!strcmp(args[0], "backlog")) {  /* backlog */
+		if (warnifnotcap(cfg_log_forward, PR_CAP_FE, file, linenum, args[0], NULL))
+			err_code |= ERR_WARN;
+
+		if (*(args[1]) == 0) {
+			ha_alert("parsing [%s:%d] : '%s' expects an integer argument.\n", file, linenum, args[0]);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+		cfg_log_forward->backlog = atol(args[1]);
+		if (alertif_too_many_args(1, file, linenum, args, &err_code))
+			goto out;
+	}
+	else if (strcmp(args[0], "bind") == 0) {
+		int cur_arg;
+		static int kws_dumped;
+		struct bind_conf *bind_conf;
+		struct bind_kw *kw;
+		struct listener *l;
+
+		cur_arg = 1;
+
+		bind_conf = bind_conf_alloc(cfg_log_forward, file, linenum,
+					    NULL, xprt_get(XPRT_RAW));
+		if (!bind_conf) {
+			ha_alert("parsing [%s:%d] : out of memory error.", file, linenum);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+
+		if (!str2listener(args[1], cfg_log_forward, bind_conf, file, linenum, &errmsg)) {
+			if (errmsg && *errmsg) {
+				indent_msg(&errmsg, 2);
+				ha_alert("parsing [%s:%d] : '%s %s' : %s\n", file, linenum, args[0], args[1], errmsg);
+			}
+			else {
+				ha_alert("parsing [%s:%d] : '%s %s' : error encountered while parsing listening address %s.\n",
+				         file, linenum, args[0], args[1], args[2]);
+				err_code |= ERR_ALERT | ERR_FATAL;
+				goto out;
+			}
+		}
+		list_for_each_entry(l, &bind_conf->listeners, by_bind) {
+			l->maxaccept = global.tune.maxaccept ? global.tune.maxaccept : 64;
+			l->accept = session_accept_fd;
+			l->analysers |=  cfg_log_forward->fe_req_ana;
+			l->default_target = cfg_log_forward->default_target;
+			global.maxsock++;
+		}
+		cur_arg++;
+
+		while (*args[cur_arg] && (kw = bind_find_kw(args[cur_arg]))) {
+			int ret;
+
+			ret = kw->parse(args, cur_arg, cfg_log_forward, bind_conf, &errmsg);
+			err_code |= ret;
+			if (ret) {
+				if (errmsg && *errmsg) {
+					indent_msg(&errmsg, 2);
+					ha_alert("parsing [%s:%d] : %s\n", file, linenum, errmsg);
+				}
+				else
+					ha_alert("parsing [%s:%d]: error encountered while processing '%s'\n",
+					         file, linenum, args[cur_arg]);
+				if (ret & ERR_FATAL)
+					goto out;
+			}
+			cur_arg += 1 + kw->skip;
+		}
+		if (*args[cur_arg] != 0) {
+			char *kws = NULL;
+
+			if (!kws_dumped) {
+				kws_dumped = 1;
+				bind_dump_kws(&kws);
+				indent_msg(&kws, 4);
+			}
+			ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.%s%s\n",
+			         file, linenum, args[cur_arg], cursection,
+			         kws ? " Registered keywords :" : "", kws ? kws: "");
+			free(kws);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+	}
 	else if (strcmp(args[0], "dgram-bind") == 0) {
 		int cur_arg;
 		static int kws_dumped;
@@ -3685,6 +3931,40 @@ int cfg_parse_log_forward(const char *file, int linenum, char **args, int kwm)
 			goto out;
 		}
 	}
+	else if (strcmp(args[0], "timeout") == 0) {
+		const char *res;
+		unsigned timeout;
+
+		if (strcmp(args[1], "client") != 0) {
+			ha_alert("parsing [%s:%d] : unknown keyword '%s %s' in log-forward section.\n", file, linenum, args[0], args[1]);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+
+		if (*args[2] == 0) {
+			ha_alert("parsing [%s:%d] : missing timeout client value.\n", file, linenum);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+		res = parse_time_err(args[2], &timeout, TIME_UNIT_MS);
+		if (res == PARSE_TIME_OVER) {
+			memprintf(&errmsg, "timer overflow in argument '%s' to 'timeout client' (maximum value is 2147483647 ms or ~24.8 days)", args[2]);
+		}
+		else if (res == PARSE_TIME_UNDER) {
+			memprintf(&errmsg, "timer underflow in argument '%s' to 'timeout client' (minimum non-null value is 1 ms)", args[2]);
+		}
+		else if (res) {
+			memprintf(&errmsg, "unexpected character '%c' in 'timeout client'", *res);
+			return -1;
+		}
+
+		if (res) {
+			ha_alert("parsing [%s:%d] : %s : %s\n", file, linenum, args[0], errmsg);
+			err_code |= ERR_ALERT | ERR_FATAL;
+			goto out;
+		}
+		cfg_log_forward->timeout.client = MS_TO_TICKS(timeout);
+	}
 	else {
 		ha_alert("parsing [%s:%d] : unknown keyword '%s' in log-forward section.\n", file, linenum, args[0]);
 		err_code |= ERR_ALERT | ERR_ABORT;