X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Flib%2Flttng-ctl%2Flttng-ctl.c;h=36069ef2816b7906bb9f19a8c0714912a8061f31;hb=b19155c048f4cb6be12d402f1708e2e4ff80fa98;hp=c62dcfa1d4b335748f5c192fe8b712120a71decb;hpb=1c8d13c8a4111fcfd4cc00c335d47506ab98bb33;p=lttng-tools.git

diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index c62dcfa1d..36069ef28 100644
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -5,19 +5,18 @@
  *
  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
  *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #define _GNU_SOURCE
@@ -41,6 +40,18 @@ static char sessiond_sock_path[PATH_MAX];
 static char *tracing_group;
 static int connected;
 
+/* Global */
+
+/*
+ * Those two variables are used by error.h to silent or control the verbosity of
+ * error message. They are global to the library so application linking with it
+ * are able to compile correctly and also control verbosity of the library.
+ *
+ * Note that it is *not* possible to silent ERR() and PERROR() macros.
+ */
+int lttng_opt_quiet;
+int lttng_opt_verbose;
+
 /*
  * Copy string from src to dst and enforce null terminated byte.
  */
@@ -74,6 +85,7 @@ static void copy_lttng_domain(struct lttng_domain *dst, struct lttng_domain *src
 				memcpy(dst, src, sizeof(struct lttng_domain));
 				break;
 			default:
+				memset(dst, 0, sizeof(struct lttng_domain));
 				dst->type = LTTNG_DOMAIN_KERNEL;
 				break;
 		}
@@ -137,11 +149,8 @@ static int check_tracing_group(const char *grp_name)
 
 	/* Get GID of group 'tracing' */
 	grp_tracing = getgrnam(grp_name);
-	if (grp_tracing == NULL) {
-		/* NULL means not found also. getgrnam(3) */
-		if (errno != 0) {
-			perror("getgrnam");
-		}
+	if (!grp_tracing) {
+		/* If grp_tracing is NULL, the group does not exist. */
 		goto end;
 	}
 
@@ -227,35 +236,33 @@ static int set_session_daemon_path(void)
 		in_tgroup = check_tracing_group(tracing_group);
 	}
 
-	if (uid == 0) {
-		/* Root */
-		copy_string(sessiond_sock_path,
-				DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
-				sizeof(sessiond_sock_path));
-	} else if (in_tgroup) {
-		/* Tracing group */
-		copy_string(sessiond_sock_path,
-				DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
+	if ((uid == 0) || in_tgroup) {
+		copy_string(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
 				sizeof(sessiond_sock_path));
+	}
 
-		ret = try_connect_sessiond(sessiond_sock_path);
-		if (ret < 0) {
-			/* Global session daemon not available */
-			if (snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
-						DEFAULT_HOME_CLIENT_UNIX_SOCK,
-						getenv("HOME")) < 0) {
-				return -ENOMEM;
+	if (uid != 0) {
+		if (in_tgroup) {
+			/* Tracing group */
+			ret = try_connect_sessiond(sessiond_sock_path);
+			if (ret >= 0) {
+				goto end;
 			}
+			/* Global session daemon not available... */
 		}
-	} else {
-		/* Not in tracing group and not root, default */
-		if (snprintf(sessiond_sock_path, PATH_MAX,
-					DEFAULT_HOME_CLIENT_UNIX_SOCK,
-					getenv("HOME")) < 0) {
+		/* ...or not in tracing group (and not root), default */
+
+		/*
+		 * With GNU C <  2.1, snprintf returns -1 if the target buffer is too small;
+		 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
+		 */
+		ret = snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
+				DEFAULT_HOME_CLIENT_UNIX_SOCK, getenv("HOME"));
+		if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
 			return -ENOMEM;
 		}
 	}
-
+end:
 	return 0;
 }
 
@@ -468,7 +475,10 @@ int lttng_stop_tracing(const char *session_name)
 }
 
 /*
- * Add context to event or/and channel.
+ * Add context to event and/or channel.
+ * If event_name is NULL, the context is applied to all events of the channel.
+ * If channel_name is NULL, a lookup of the event's channel is done.
+ * If both are NULL, the context is applied to all events of all channels.
  *
  * Returns the size of the returned payload data or a negative error code.
  */
@@ -483,6 +493,8 @@ int lttng_add_context(struct lttng_handle *handle,
 		return -1;
 	}
 
+	memset(&lsm, 0, sizeof(lsm));
+
 	lsm.cmd_type = LTTNG_ADD_CONTEXT;
 
 	/* Copy channel name */
@@ -517,6 +529,8 @@ int lttng_enable_event(struct lttng_handle *handle,
 		return -1;
 	}
 
+	memset(&lsm, 0, sizeof(lsm));
+
 	/* If no channel name, we put the default name */
 	if (channel_name == NULL) {
 		copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
@@ -556,6 +570,8 @@ int lttng_disable_event(struct lttng_handle *handle, const char *name,
 		return -1;
 	}
 
+	memset(&lsm, 0, sizeof(lsm));
+
 	if (channel_name) {
 		copy_string(lsm.u.disable.channel_name, channel_name,
 				sizeof(lsm.u.disable.channel_name));
@@ -595,6 +611,8 @@ int lttng_enable_channel(struct lttng_handle *handle,
 		return -1;
 	}
 
+	memset(&lsm, 0, sizeof(lsm));
+
 	memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
 
 	lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
@@ -620,6 +638,8 @@ int lttng_disable_channel(struct lttng_handle *handle, const char *name)
 		return -1;
 	}
 
+	memset(&lsm, 0, sizeof(lsm));
+
 	lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
 
 	copy_string(lsm.u.disable.channel_name, name,
@@ -860,11 +880,13 @@ int lttng_calibrate(struct lttng_handle *handle,
 
 /*
  * Set default channel attributes.
- * If either or both of the arguments are null, nothing happens.
+ * If either or both of the arguments are null, attr content is zeroe'd.
  */
 void lttng_channel_set_default_attr(struct lttng_domain *domain,
 		struct lttng_channel_attr *attr)
 {
+	memset(attr, 0, sizeof(struct lttng_channel_attr));
+
 	/* Safety check */
 	if (attr == NULL || domain == NULL) {
 		return;
@@ -895,8 +917,7 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
 		attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
 		break;
 	default:
-		/* Default behavior */
-		memset(attr, 0, sizeof(struct lttng_channel_attr));
+		/* Default behavior: leave set to 0. */
 		break;
 	}
 }