[tarantool-patches] [PATCH v2 1/3] Configurable syslog destination

[Olga Arkhangelskaia <arkholga@tarantool.org>]

Added server option to syslog configuration.
Server option is responsible for log destination. At the momemt
there is two ways of usage:server=unix:/path/to/socket or
server=ipv4:port. If port is not set default udp port 514 is used.
If logging to syslog is set, however there is no sever options -
default location is used: Linux /dev/log and Mac /var/run/syslog.

Issue: #3487
---
https://github.com/tarantool/tarantool/issues/3487

Branch:https: OKriw/gh-3487-syslog-conf-dest
---
https://github.com/tarantool/tarantool/tree/OKriw/gh-3487-syslog-conf-dest

gh-3487-syslog-conf-dest 
 src/say.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 src/say.h |  14 ++++++++-
 2 files changed, 112 insertions(+), 8 deletions(-)

diff --git a/src/say.c b/src/say.c
index 43124083c..50416c08d 100644
--- a/src/say.c
+++ b/src/say.c
@@ -36,6 +36,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
+#include <netdb.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -52,6 +53,8 @@ enum say_format log_format = SF_PLAIN;
 /** List of logs to rotate */
 static RLIST_HEAD(log_rotate_list);
 
+static const char syslog_syntax_remainder[] =
+        "expecting syslog: or syslog:server=ip:potr or syslog:server=unix:/path";
 static const char logger_syntax_reminder[] =
 	"expecting a file name or a prefix, such as '|', 'pipe:', 'syslog:'";
 /**
@@ -473,16 +476,80 @@ syslog_connect_unix(const char *path)
 	return fd;
 }
 
+/**
+ * Connect to remote syslogd using server:port.
+ * @param ip address of remote host.
+ * @param port on remote host.
+ * @retval not 0 Socket descriptor.
+ * @retval    -1 Socket error.
+ */
+static int
+syslog_connect_remote(const char *server_address)
+{
+	/* IPv4 */
+	struct addrinfo *inf, hints, *ptr;
+	const char *remote;
+	char *portnum, *copy;
+	int fd = -1;
+
+	copy = strdup(server_address);
+	if (copy == NULL) {
+		diag_set(OutOfMemory, strlen(server_address), "malloc",
+			 copy);
+		return fd;
+	}
+	portnum = copy;
+	remote = strsep(&portnum, ":");
+	if (!remote) {
+		diag_set(IllegalParams,syslog_syntax_remainder);
+		free(copy);
+		return fd;
+	}
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = IPPROTO_UDP;
+	hints.ai_flags = AI_DEFAULT;
+
+	if (getaddrinfo(remote, portnum, NULL, &inf) < 0) {
+		free(copy);
+		return -1;
+	}
+	for (ptr = inf; ptr; ptr = ptr->ai_next) {
+		fd = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);
+		if (fd < 0) {
+			continue;
+		}
+
+		if (connect(fd, inf->ai_addr, inf->ai_addrlen) != 0) {
+			close(fd);
+			fd = -1;
+			continue;
+		}
+		break;
+	}
+	freeaddrinfo(inf);
+	free(copy);
+	return fd;
+}
+
 static inline int
 log_syslog_connect(struct log *log)
 {
+
 	/*
-	 * Try two locations: '/dev/log' for Linux and
+	 * If server option is not set use '/dev/log' for Linux and
 	 * '/var/run/syslog' for Mac.
 	 */
-	log->fd = syslog_connect_unix("/dev/log");
-	if (log->fd < 0)
-		log->fd = syslog_connect_unix("/var/run/syslog");
+	if (log->server_type == SAY_SYSLOG_LOCAL) {
+		log->fd = syslog_connect_unix("/dev/log");
+			if (log->fd < 0)
+				log->fd = syslog_connect_unix("/var/run/syslog");
+	} else if (log->server_type == SAY_SYSLOG_UNIX) {
+		log->fd = syslog_connect_unix(log->path);
+	} else {
+		log->fd = syslog_connect_remote(log->path);
+	}
 	return log->fd;
 }
 
@@ -498,6 +565,17 @@ log_syslog_init(struct log *log, const char *init_str)
 	if (say_parse_syslog_opts(init_str, &opts) < 0)
 		return -1;
 
+	log->server_type = opts.syslog_server;
+	if (log->server_type == SAY_SYSLOG_LOCAL)
+		log->path = NULL;
+	else {
+		log->path = strdup(opts.server);
+			if (log->path == NULL) {
+				diag_set(OutOfMemory, strlen(init_str),
+				         "malloc", "log->path");
+			return -1;
+		}
+	}
 	if (opts.identity == NULL)
 		log->syslog_ident = strdup("tarantool");
 	else
@@ -1044,6 +1122,8 @@ say_syslog_facility_by_name(const char *facility)
 int
 say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
 {
+	opts->server = NULL;
+	opts->syslog_server = SAY_SYSLOG_LOCAL;
 	opts->identity = NULL;
 	opts->facility = syslog_facility_MAX;
 	opts->copy = strdup(init_str);
@@ -1051,8 +1131,8 @@ say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
 		diag_set(OutOfMemory, strlen(init_str), "malloc", "opts->copy");
 		return -1;
 	}
-	char *ptr = opts->copy;
-	const char *option, *value;
+	char *ptr = opts->copy; 
+	const char *option, *value, *srv_str;
 
 	/* strsep() overwrites the separator with '\0' */
 	while ((option = strsep(&ptr, ","))) {
@@ -1060,7 +1140,19 @@ say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
 			break;
 
 		value = option;
-		if (say_parse_prefix(&value, "identity=")) {
+		srv_str = say_parse_prefix(&value, "server=");
+		if (srv_str != NULL) {
+			if (opts->server != NULL ||
+			    opts->syslog_server != SAY_SYSLOG_LOCAL)
+				goto duplicate;
+			if (say_parse_prefix(&srv_str, "unix:")) {
+				opts->syslog_server = SAY_SYSLOG_UNIX;
+				opts->server = srv_str;
+			} else {
+				opts->syslog_server = SAY_SYSLOG_REMOTE;
+				opts->server = srv_str;
+			}
+		} else if (say_parse_prefix(&value, "identity=")) {
 			if (opts->identity != NULL)
 				goto duplicate;
 			opts->identity = value;
diff --git a/src/say.h b/src/say.h
index ad3ba3417..a1b6c2331 100644
--- a/src/say.h
+++ b/src/say.h
@@ -79,6 +79,12 @@ say_log_level_is_enabled(int level)
 
 extern enum say_format log_format;
 
+enum say_logger_syslog_server {
+	SAY_SYSLOG_LOCAL,
+	SAY_SYSLOG_UNIX,
+	SAY_SYSLOG_REMOTE
+};
+
 enum say_logger_type {
 	/**
 	 * Before the app server core is initialized, we do not
@@ -141,7 +147,10 @@ struct log {
 	/** The current log level. */
 	int level;
 	enum say_logger_type type;
-	/** path to file if logging to file. */
+	enum say_logger_syslog_server server_type;
+	/** path to file if logging to file
+	 * or server address in case of syslog
+	 * */
 	char *path;
 	bool nonblock;
 	log_format_func_t format_func;
@@ -162,6 +171,7 @@ struct log {
 	int rotating_threads;
 	enum syslog_facility syslog_facility;
 	struct rlist in_log_list;
+	/* Server options. Either ip/port pair or unix socket address.*/
 };
 
 /**
@@ -390,6 +400,8 @@ say_parse_logger_type(const char **str, enum say_logger_type *type);
 
 /** Syslog logger initialization params */
 struct say_syslog_opts {
+	enum say_logger_syslog_server syslog_server;
+	const char *server;
 	const char *identity;
 	enum syslog_facility facility;
 	/* Input copy (content unspecified). */
-- 
2.14.3 (Apple Git-98)