MINOR: log: Extract some code to send syslog messages.

This patch extracts the code of __send_log() responsible of sending a syslog
message to a syslog destination represented as a logsrv struct to define
__do_send_log() function. __send_log() calls __do_send_log() for each syslog
destination of a proxy after having prepared some of its parameters.

src/log.c

@@ -1310,13 +1310,16 @@ void send_log(struct proxy *p, int level, const char *format, ...)
 }
 
 /*
- * This function sends a syslog message.
+ * This function sends a syslog message to <logsrv>.
- * It doesn't care about errors nor does it report them.
+ * <pid_str> is the string to be used for the PID of the caller, <pid_size> is length.
+ * Same thing for <sd> and <sd_size> which are used for the structured-data part
+ * in RFC5424 formatted syslog messages, and <tag_str> and <tag_size> the syslog tag.
  * It overrides the last byte of the message vector with an LF character.
- * The arguments <sd> and <sd_size> are used for the structured-data part
+ * Does not return any error,
- * in RFC5424 formatted syslog messages.
  */
-void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd, size_t sd_size)
+static inline void __do_send_log(struct logsrv *logsrv, int nblogger, char *pid_str, size_t pid_size,
+                                 int level, char *message, size_t size, char *sd, size_t sd_size,
+                                 char *tag_str, size_t tag_size)
 {
 	static THREAD_LOCAL struct iovec iovec[NB_MSG_IOVEC_ELEMENTS] = { };
 	static THREAD_LOCAL struct msghdr msghdr = {
@@ -1326,48 +1329,11 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 	static THREAD_LOCAL int logfdunix = -1;	/* syslog to AF_UNIX socket */
 	static THREAD_LOCAL int logfdinet = -1;	/* syslog to AF_INET socket */
 	static THREAD_LOCAL char *dataptr = NULL;
-	int fac_level;
+	time_t time = date.tv_sec;
-	struct list *logsrvs = NULL;
-	struct logsrv *tmp = NULL;
-	int nblogger;
 	char *hdr, *hdr_ptr;
 	size_t hdr_size;
-	time_t time = date.tv_sec;
 	struct buffer *tag = &global.log_tag;
-	static THREAD_LOCAL int curr_pid;
+	int fac_level;
-	static THREAD_LOCAL char pidstr[100];
-	static THREAD_LOCAL struct buffer pid;
-
-	msghdr.msg_iov = iovec;
-
-	dataptr = message;
-
-	if (p == NULL) {
-		if (!LIST_ISEMPTY(&global.logsrvs)) {
-			logsrvs = &global.logsrvs;
-		}
-	} else {
-		if (!LIST_ISEMPTY(&p->logsrvs)) {
-			logsrvs = &p->logsrvs;
-		}
-		if (p->log_tag.area) {
-			tag = &p->log_tag;
-		}
-	}
-
-	if (!logsrvs)
-		return;
-
-	if (unlikely(curr_pid != getpid())) {
-		curr_pid = getpid();
-		ltoa_o(curr_pid, pidstr, sizeof(pidstr));
-		chunk_initstr(&pid, pidstr);
-	}
-
-	/* Send log messages to syslog server. */
-	nblogger = 0;
-	list_for_each_entry(tmp, logsrvs, list) {
-		const struct logsrv *logsrv = tmp;
 	int *plogfd;
 	char *pid_sep1 = "", *pid_sep2 = "";
 	char logheader_short[3];
@@ -1376,16 +1342,13 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 	int hdr_max = 0;
 	int tag_max = 0;
 	int pid_sep1_max = 0;
-		int pid_max = 0;
 	int pid_sep2_max = 0;
 	int sd_max = 0;
 	int max = 0;
 
-		nblogger++;
+	msghdr.msg_iov = iovec;
 
-		/* we can filter the level of the messages that are sent to each logger */
+	dataptr = message;
-		if (level > logsrv->level)
-			continue;
 
 	if (logsrv->addr.ss_family == AF_UNSPEC) {
 		/* the socket's address is a file descriptor */
@@ -1415,7 +1378,7 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 				ha_alert("socket() failed in logger #%d: %s (errno=%d)\n",
 						 nblogger, strerror(errno), errno);
 			}
-				continue;
+			return;
 		} else {
 			/* we don't want to receive anything on this socket */
 			setsockopt(*plogfd, SOL_SOCKET, SO_RCVBUF, &zero, sizeof(zero));
@@ -1458,7 +1421,7 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 		goto send;
 
 	default:
-			continue; /* must never happen */
+		return; /* must never happen */
 	}
 
 	hdr_size = hdr_ptr - hdr;
@@ -1512,14 +1475,13 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 	maxlen -= pid_sep1_max;
 
 	/* pid */
-		pid_max = pid.data;
+	if (unlikely(pid_size >= maxlen)) {
-		if (unlikely(pid_max >= maxlen)) {
+		pid_size = maxlen - 1;
-			pid_max = maxlen - 1;
 		sd_max = 0;
 		goto send;
 	}
 
-		maxlen -= pid_max;
+	maxlen -= pid_size;
 
 	/* second pid separator */
 	pid_sep2_max = log_formats[logsrv->format].pid.sep2.data;
@@ -1542,12 +1504,12 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 send:
 	iovec[0].iov_base = hdr_ptr;
 	iovec[0].iov_len  = hdr_max;
-		iovec[1].iov_base = tag->area;
+	iovec[1].iov_base = tag_str;
-		iovec[1].iov_len  = tag_max;
+	iovec[1].iov_len  = tag_size;
 	iovec[2].iov_base = pid_sep1;
 	iovec[2].iov_len  = pid_sep1_max;
-		iovec[3].iov_base = pid.area;
+	iovec[3].iov_base = pid_str;
-		iovec[3].iov_len  = pid_max;
+	iovec[3].iov_len  = pid_size;
 	iovec[4].iov_base = pid_sep2;
 	iovec[4].iov_len  = pid_sep2_max;
 	iovec[5].iov_base = sd;
@@ -1580,6 +1542,55 @@ void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd
 		}
 	}
 }
+
+/*
+ * This function sends a syslog message.
+ * It doesn't care about errors nor does it report them.
+ * The arguments <sd> and <sd_size> are used for the structured-data part
+ * in RFC5424 formatted syslog messages.
+ */
+void __send_log(struct proxy *p, int level, char *message, size_t size, char *sd, size_t sd_size)
+{
+	struct list *logsrvs = NULL;
+	struct logsrv *logsrv;
+	int nblogger;
+	static THREAD_LOCAL int curr_pid;
+	static THREAD_LOCAL char pidstr[100];
+	static THREAD_LOCAL struct buffer pid;
+	struct buffer *tag = &global.log_tag;
+
+	if (p == NULL) {
+		if (!LIST_ISEMPTY(&global.logsrvs)) {
+			logsrvs = &global.logsrvs;
+		}
+	} else {
+		if (!LIST_ISEMPTY(&p->logsrvs)) {
+			logsrvs = &p->logsrvs;
+		}
+		if (p->log_tag.area) {
+			tag = &p->log_tag;
+		}
+	}
+
+	if (!logsrvs)
+		return;
+
+	if (unlikely(curr_pid != getpid())) {
+		curr_pid = getpid();
+		ltoa_o(curr_pid, pidstr, sizeof(pidstr));
+		chunk_initstr(&pid, pidstr);
+	}
+
+	/* Send log messages to syslog server. */
+	nblogger = 0;
+	list_for_each_entry(logsrv, logsrvs, list) {
+		/* we can filter the level of the messages that are sent to each logger */
+		if (level > logsrv->level)
+			continue;
+
+		__do_send_log(logsrv, ++nblogger, pid.area, pid.data, level,
+		              message, size, sd, sd_size, tag->area, tag->data);
+	}
 }
 
 extern fd_set hdr_encode_map[];