Fix: Lib lttng-ctl on error returns lttng code

The library was returning negative value that were NOT a lttng error
code documented in lttng-error.h. This was problematic because the
lttng_strerror() could not recognized the returned code and thus the
caller was clueless about the error.

This patch makes sure every lttng-ctl calls return either the correct
documented positive value or a negative lttng error code on error that
can be directly translate by lttng_strerror() which takes a negative
lttng code.

Small fix: enable event command, when hitting a loglevel error now
returns a lttng error code and does not print the help anymore.

Fixes #337

Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/include/lttng/lttng-error.h b/include/lttng/lttng-error.h
index 3c28d160337bd3fd0f6de29cc0b1b8bb2b3b949c..0eeb74616a210f60c630ca176be87a7a24a6fe3e 100644 (file)
--- a/include/lttng/lttng-error.h
+++ b/include/lttng/lttng-error.h
@@ -39,7 +39,7 @@ enum lttng_error_code {
        LTTNG_ERR_NO_SESSION             = 16,  /* No session found */
        LTTNG_ERR_CREATE_DIR_FAIL        = 17,  /* Create directory fail */
        LTTNG_ERR_SESSION_FAIL           = 18,  /* Create session fail */
-       /* 19 */
+       LTTNG_ERR_NO_SESSIOND            = 19,  /* No session daemon available */
        /* 20 */
        /* 21 */
        /* 22 */

diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
index 0bd96eb303680cc715dced1bda4eb845d74c75eb..51388298954768d35990b38e540617fc008e4020 100644 (file)
--- a/src/bin/lttng/commands/enable_events.c
+++ b/src/bin/lttng/commands/enable_events.c
@@ -358,7 +358,7 @@ static int enable_events(char *session_name)
                                ev.loglevel = loglevel_str_to_value(opt_loglevel);
                                if (ev.loglevel == -1) {
                                        ERR("Unknown loglevel %s", opt_loglevel);
-                                       ret = -1;
+                                       ret = -LTTNG_ERR_INVALID;
                                        goto error;
                                }
                        } else {
@@ -546,7 +546,7 @@ static int enable_events(char *session_name)
                                ev.loglevel = loglevel_str_to_value(opt_loglevel);
                                if (ev.loglevel == -1) {
                                        ERR("Unknown loglevel %s", opt_loglevel);
-                                       ret = -1;
+                                       ret = -LTTNG_ERR_INVALID;
                                        goto error;
                                }
                        } else {

diff --git a/src/common/error.c b/src/common/error.c
index d5403d804d5c9dc658fcff946a1e74c074bf97a5..ce11bf208ad7e05a3292eb790d56885916aa66d7 100644 (file)
--- a/src/common/error.c
+++ b/src/common/error.c
@@ -98,6 +98,7 @@ static const char *error_string_array[] = {
        [ ERROR_INDEX(LTTNG_ERR_FILTER_NOMEM) ] = "Not enough memory for filter bytecode",
        [ ERROR_INDEX(LTTNG_ERR_FILTER_EXIST) ] = "Filter already exist",
        [ ERROR_INDEX(LTTNG_ERR_NO_CONSUMER) ] = "Consumer not found for tracing session",
+       [ ERROR_INDEX(LTTNG_ERR_NO_SESSIOND) ] = "No session daemon is available",
 
        /* Last element */
        [ ERROR_INDEX(LTTNG_ERR_NR) ] = "Unknown error code"

diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index e4560bb7fb927895d5b11fd84db2338001b0507b..edaebf59c8654515ac7872d0888e4a84dd6ab0ad 100644 (file)
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -253,7 +253,7 @@ static int send_session_msg(struct lttcomm_session_msg *lsm)
        int ret;
 
        if (!connected) {
-               ret = -ENOTCONN;
+               ret = -LTTNG_ERR_NO_SESSIOND;
                goto end;
        }
 
@@ -261,6 +261,9 @@ static int send_session_msg(struct lttcomm_session_msg *lsm)
 
        ret = lttcomm_send_creds_unix_sock(sessiond_socket, lsm,
                        sizeof(struct lttcomm_session_msg));
+       if (ret < 0) {
+               ret = -LTTNG_ERR_FATAL;
+       }
 
 end:
        return ret;
@@ -277,7 +280,7 @@ static int send_session_varlen(void *data, size_t len)
        int ret;
 
        if (!connected) {
-               ret = -ENOTCONN;
+               ret = -LTTNG_ERR_NO_SESSIOND;
                goto end;
        }
 
@@ -287,6 +290,9 @@ static int send_session_varlen(void *data, size_t len)
        }
 
        ret = lttcomm_send_unix_sock(sessiond_socket, data, len);
+       if (ret < 0) {
+               ret = -LTTNG_ERR_FATAL;
+       }
 
 end:
        return ret;
@@ -303,11 +309,14 @@ static int recv_data_sessiond(void *buf, size_t len)
        int ret;
 
        if (!connected) {
-               ret = -ENOTCONN;
+               ret = -LTTNG_ERR_NO_SESSIOND;
                goto end;
        }
 
        ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
+       if (ret < 0) {
+               ret = -LTTNG_ERR_FATAL;
+       }
 
 end:
        return ret;
@@ -378,13 +387,13 @@ static int try_connect_sessiond(const char *sock_path)
        ret = access(sock_path, F_OK);
        if (ret < 0) {
                /* Not alive */
-               return -1;
+               goto error;
        }
 
        ret = lttcomm_connect_unix_sock(sock_path);
        if (ret < 0) {
                /* Not alive */
-               return -1;
+               goto error;
        }
 
        ret = lttcomm_close_unix_sock(ret);
@@ -393,13 +402,17 @@ static int try_connect_sessiond(const char *sock_path)
        }
 
        return 0;
+
+error:
+       return -1;
 }
 
 /*
- * Set sessiond socket path by putting it in the global
- * sessiond_sock_path variable.
- * Returns 0 on success,
- * -ENOMEM on failure (the sessiond socket path is somehow too long)
+ * Set sessiond socket path by putting it in the global sessiond_sock_path
+ * variable.
+ *
+ * Returns 0 on success, negative value on failure (the sessiond socket path
+ * is somehow too long or ENOMEM).
  */
 static int set_session_daemon_path(void)
 {
@@ -437,11 +450,14 @@ static int set_session_daemon_path(void)
                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;
+                       goto error;
                }
        }
 end:
        return 0;
+
+error:
+       return -1;
 }
 
 /*
@@ -455,19 +471,22 @@ static int connect_sessiond(void)
 
        ret = set_session_daemon_path();
        if (ret < 0) {
-               return -1; /* set_session_daemon_path() returns -ENOMEM */
+               goto error;
        }
 
        /* Connect to the sesssion daemon */
        ret = lttcomm_connect_unix_sock(sessiond_sock_path);
        if (ret < 0) {
-               return ret;
+               goto error;
        }
 
        sessiond_socket = ret;
        connected = 1;
 
        return 0;
+
+error:
+       return -1;
 }
 
 /*
@@ -503,23 +522,27 @@ static int ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
 
        ret = connect_sessiond();
        if (ret < 0) {
+               ret = -LTTNG_ERR_NO_SESSIOND;
                goto end;
        }
 
        /* Send command to session daemon */
        ret = send_session_msg(lsm);
        if (ret < 0) {
+               /* Ret value is a valid lttng error code. */
                goto end;
        }
        /* Send var len data */
        ret = send_session_varlen(vardata, varlen);
        if (ret < 0) {
+               /* Ret value is a valid lttng error code. */
                goto end;
        }
 
        /* Get header from data transmission */
        ret = recv_data_sessiond(&llm, sizeof(llm));
        if (ret < 0) {
+               /* Ret value is a valid lttng error code. */
                goto end;
        }
 
@@ -553,7 +576,7 @@ static int ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
         * this point, an error is returned and data is freed.
         */
        if (buf == NULL) {
-               ret = -1;
+               ret = -LTTNG_ERR_INVALID;
                free(data);
                goto end;
        }
@@ -583,11 +606,15 @@ static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
 struct lttng_handle *lttng_create_handle(const char *session_name,
                struct lttng_domain *domain)
 {
-       struct lttng_handle *handle;
+       struct lttng_handle *handle = NULL;
+
+       if (domain == NULL) {
+               goto end;
+       }
 
        handle = malloc(sizeof(struct lttng_handle));
        if (handle == NULL) {
-               perror("malloc handle");
+               PERROR("malloc handle");
                goto end;
        }
 
@@ -621,6 +648,10 @@ int lttng_register_consumer(struct lttng_handle *handle,
 {
        struct lttcomm_session_msg lsm;
 
+       if (handle == NULL || socket_path == NULL) {
+               return -LTTNG_ERR_INVALID;
+       }
+
        lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
        copy_string(lsm.session.name, handle->session_name,
                        sizeof(lsm.session.name));
@@ -640,7 +671,7 @@ int lttng_start_tracing(const char *session_name)
        struct lttcomm_session_msg lsm;
 
        if (session_name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_START_TRACE;
@@ -659,7 +690,7 @@ int lttng_stop_tracing(const char *session_name)
        struct lttcomm_session_msg lsm;
 
        if (session_name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_STOP_TRACE;
@@ -685,7 +716,7 @@ int lttng_add_context(struct lttng_handle *handle,
 
        /* Safety check. Both are mandatory */
        if (handle == NULL || ctx == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -721,7 +752,7 @@ int lttng_enable_event(struct lttng_handle *handle,
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL || ev == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -767,7 +798,7 @@ int lttng_set_event_filter(struct lttng_handle *handle,
 
        /* Safety check. */
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        if (!filter_expression) {
@@ -895,7 +926,7 @@ int lttng_disable_event(struct lttng_handle *handle, const char *name,
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -936,7 +967,7 @@ int lttng_enable_channel(struct lttng_handle *handle,
         * NULL arguments are forbidden. No default values.
         */
        if (handle == NULL || chan == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -963,7 +994,7 @@ int lttng_disable_channel(struct lttng_handle *handle, const char *name)
 
        /* Safety check. Both are mandatory */
        if (handle == NULL || name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -994,7 +1025,7 @@ int lttng_list_tracepoints(struct lttng_handle *handle,
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
@@ -1021,7 +1052,7 @@ int lttng_list_tracepoint_fields(struct lttng_handle *handle,
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
@@ -1056,7 +1087,7 @@ int lttng_create_session(const char *name, const char *url)
        struct lttng_uri *uris = NULL;
 
        if (name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -1067,7 +1098,7 @@ int lttng_create_session(const char *name, const char *url)
        /* There should never be a data URL */
        size = parse_str_urls_to_uri(url, NULL, &uris);
        if (size < 0) {
-               return LTTNG_ERR_INVALID;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.u.uri.size = size;
@@ -1085,7 +1116,7 @@ int lttng_destroy_session(const char *session_name)
        struct lttcomm_session_msg lsm;
 
        if (session_name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_DESTROY_SESSION;
@@ -1128,7 +1159,7 @@ int lttng_list_domains(const char *session_name,
        struct lttcomm_session_msg lsm;
 
        if (session_name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_LIST_DOMAINS;
@@ -1156,7 +1187,7 @@ int lttng_list_channels(struct lttng_handle *handle,
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_LIST_CHANNELS;
@@ -1187,7 +1218,7 @@ int lttng_list_events(struct lttng_handle *handle,
 
        /* Safety check. An handle and channel name are mandatory */
        if (handle == NULL || channel_name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_LIST_EVENTS;
@@ -1214,11 +1245,11 @@ int lttng_list_events(struct lttng_handle *handle,
 int lttng_set_tracing_group(const char *name)
 {
        if (name == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        if (asprintf(&tracing_group, "%s", name) < 0) {
-               return -ENOMEM;
+               return -LTTNG_ERR_FATAL;
        }
 
        return 0;
@@ -1234,7 +1265,7 @@ int lttng_calibrate(struct lttng_handle *handle,
 
        /* Safety check. NULL pointer are forbidden */
        if (handle == NULL || calibrate == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_CALIBRATE;
@@ -1306,8 +1337,11 @@ int lttng_session_daemon_alive(void)
        }
 
        if (strlen(sessiond_sock_path) == 0) {
-               /* No socket path set. Weird error */
-               return -1;
+               /*
+                * No socket path set. Weird error which means the constructor was not
+                * called.
+                */
+               assert(0);
        }
 
        ret = try_connect_sessiond(sessiond_sock_path);
@@ -1333,7 +1367,7 @@ int lttng_set_consumer_url(struct lttng_handle *handle,
        struct lttng_uri *uris = NULL;
 
        if (handle == NULL || (control_url == NULL && data_url == NULL)) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -1346,7 +1380,7 @@ int lttng_set_consumer_url(struct lttng_handle *handle,
 
        size = parse_str_urls_to_uri(control_url, data_url, &uris);
        if (size < 0) {
-               return LTTNG_ERR_INVALID;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.u.uri.size = size;
@@ -1365,7 +1399,7 @@ int lttng_enable_consumer(struct lttng_handle *handle)
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_ENABLE_CONSUMER;
@@ -1387,7 +1421,7 @@ int lttng_disable_consumer(struct lttng_handle *handle)
        struct lttcomm_session_msg lsm;
 
        if (handle == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.cmd_type = LTTNG_DISABLE_CONSUMER;
@@ -1449,11 +1483,9 @@ static int set_health_socket_path(void)
 /*
  * Check session daemon health for a specific health component.
  *
- * Return 0 if health is OK or else 1 if BAD. A return value of -1 indicate
- * that the control library was not able to connect to the session daemon
- * health socket.
+ * Return 0 if health is OK or else 1 if BAD.
  *
- * Any other positive value is an lttcomm error which can be translate with
+ * Any other negative value is a lttng error code which can be translated with
  * lttng_strerror().
  */
 int lttng_health_check(enum lttng_health_component c)
@@ -1465,7 +1497,7 @@ int lttng_health_check(enum lttng_health_component c)
        /* Connect to the sesssion daemon */
        sock = lttcomm_connect_unix_sock(health_sock_path);
        if (sock < 0) {
-               ret = -1;
+               ret = -LTTNG_ERR_NO_SESSIOND;
                goto error;
        }
 
@@ -1474,11 +1506,13 @@ int lttng_health_check(enum lttng_health_component c)
 
        ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
        if (ret < 0) {
+               ret = -LTTNG_ERR_FATAL;
                goto close_error;
        }
 
        ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
        if (ret < 0) {
+               ret = -LTTNG_ERR_FATAL;
                goto close_error;
        }
 
@@ -1518,7 +1552,7 @@ int _lttng_create_session_ext(const char *name, const char *url,
        struct lttng_uri *uris = NULL;
 
        if (name == NULL || datetime == NULL) {
-               return -1;
+               return -LTTNG_ERR_INVALID;
        }
 
        memset(&lsm, 0, sizeof(lsm));
@@ -1529,7 +1563,7 @@ int _lttng_create_session_ext(const char *name, const char *url,
                                name, datetime);
                if (ret < 0) {
                        PERROR("snprintf session name datetime");
-                       return -1;
+                       return -LTTNG_ERR_FATAL;
                }
        } else {
                copy_string(lsm.session.name, name, sizeof(lsm.session.name));
@@ -1538,7 +1572,7 @@ int _lttng_create_session_ext(const char *name, const char *url,
        /* There should never be a data URL */
        size = parse_str_urls_to_uri(url, NULL, &uris);
        if (size < 0) {
-               return LTTNG_ERR_INVALID;
+               return -LTTNG_ERR_INVALID;
        }
 
        lsm.u.uri.size = size;
@@ -1548,7 +1582,7 @@ int _lttng_create_session_ext(const char *name, const char *url,
                                datetime);
                if (ret < 0) {
                        PERROR("snprintf uri subdir");
-                       return -1;
+                       return -LTTNG_ERR_FATAL;
                }
        }