Add non-root support for UST tracing

User-space tracing can now be used without root access meaning that the
session daemon can run with the user credentials and trace his own
applications.

This adds the LTTNG_HOME_RUNDIR which is located, under non privileged
user, in $HOME/.lttng. It contains all the control and consumers
sockets. It is cleanup when lttng-sessiond dies.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>

diff --git a/include/lttng-consumerd.h b/include/lttng-consumerd.h
index 1cd78571bba2704f4c42c1e157c95ef5836646ef..e42b2fea5b9eddc9ec2cd5300c5606b25999aeaa 100644 (file)
--- a/include/lttng-consumerd.h
+++ b/include/lttng-consumerd.h
@@ -20,18 +20,20 @@
 #ifndef _LTTNG_CONSUMERD_H
 #define _LTTNG_CONSUMERD_H
 
+#define CONSUMERD_RUNDIR                    "%s"
+
 /* Kernel consumer path */
-#define KCONSUMERD_PATH                     LTTNG_RUNDIR "/kconsumerd"
+#define KCONSUMERD_PATH                     CONSUMERD_RUNDIR "/kconsumerd"
 #define KCONSUMERD_CMD_SOCK_PATH            KCONSUMERD_PATH "/command"
 #define KCONSUMERD_ERR_SOCK_PATH            KCONSUMERD_PATH "/error"
 
 /* UST 64-bit consumer path */
-#define USTCONSUMERD64_PATH                 LTTNG_RUNDIR "/ustconsumerd64"
+#define USTCONSUMERD64_PATH                 CONSUMERD_RUNDIR "/ustconsumerd64"
 #define USTCONSUMERD64_CMD_SOCK_PATH        USTCONSUMERD64_PATH "/command"
 #define USTCONSUMERD64_ERR_SOCK_PATH        USTCONSUMERD64_PATH "/error"
 
 /* UST 32-bit consumer path */
-#define USTCONSUMERD32_PATH                 LTTNG_RUNDIR "/ustconsumerd32"
+#define USTCONSUMERD32_PATH                 CONSUMERD_RUNDIR "/ustconsumerd32"
 #define USTCONSUMERD32_CMD_SOCK_PATH        USTCONSUMERD32_PATH "/command"
 #define USTCONSUMERD32_ERR_SOCK_PATH        USTCONSUMERD32_PATH "/error"
 

diff --git a/include/lttng-sessiond-comm.h b/include/lttng-sessiond-comm.h
index 3d31ff842c4f0fcc0015b894b72ff1a7d557b63d..74d7dc99cef1385c518e13286f6085313292da3a 100644 (file)
--- a/include/lttng-sessiond-comm.h
+++ b/include/lttng-sessiond-comm.h
@@ -30,12 +30,13 @@
 #include <lttng/lttng.h>
 
 #define LTTNG_RUNDIR                        "/var/run/lttng"
+#define LTTNG_HOME_RUNDIR                   "%s/.lttng"
 
 /* Default unix socket path */
 #define DEFAULT_GLOBAL_CLIENT_UNIX_SOCK     LTTNG_RUNDIR "/client-lttng-sessiond"
 #define DEFAULT_GLOBAL_APPS_UNIX_SOCK       LTTNG_RUNDIR "/apps-lttng-sessiond"
-#define DEFAULT_HOME_APPS_UNIX_SOCK         "%s/.apps-lttng-sessiond"
-#define DEFAULT_HOME_CLIENT_UNIX_SOCK       "%s/.client-lttng-sessiond"
+#define DEFAULT_HOME_APPS_UNIX_SOCK         LTTNG_HOME_RUNDIR "/apps-lttng-sessiond"
+#define DEFAULT_HOME_CLIENT_UNIX_SOCK       LTTNG_HOME_RUNDIR "/client-lttng-sessiond"
 
 /* Queue size of listen(2) */
 #define LTTNG_SESSIOND_COMM_MAX_LISTEN 64

diff --git a/lttng-consumerd/lttng-consumerd.c b/lttng-consumerd/lttng-consumerd.c
index dce188aced643c282f71f4f7d114ad92f05374e8..cf515a9df7cae5090f4f2537b1fda39342fcfffc 100644 (file)
--- a/lttng-consumerd/lttng-consumerd.c
+++ b/lttng-consumerd/lttng-consumerd.c
@@ -251,13 +251,16 @@ int main(int argc, char **argv)
        if (strlen(command_sock_path) == 0) {
                switch (opt_type) {
                case LTTNG_CONSUMER_KERNEL:
-                       strcpy(command_sock_path, KCONSUMERD_CMD_SOCK_PATH);
+                       snprintf(command_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH,
+                                       LTTNG_RUNDIR);
                        break;
                case LTTNG_CONSUMER64_UST:
-                       strcpy(command_sock_path, USTCONSUMERD64_CMD_SOCK_PATH);
+                       snprintf(command_sock_path, PATH_MAX,
+                                       USTCONSUMERD64_CMD_SOCK_PATH, LTTNG_RUNDIR);
                        break;
                case LTTNG_CONSUMER32_UST:
-                       strcpy(command_sock_path, USTCONSUMERD32_CMD_SOCK_PATH);
+                       snprintf(command_sock_path, PATH_MAX,
+                                       USTCONSUMERD32_CMD_SOCK_PATH, LTTNG_RUNDIR);
                        break;
                default:
                        WARN("Unknown consumerd type");
@@ -275,13 +278,16 @@ int main(int argc, char **argv)
        if (strlen(error_sock_path) == 0) {
                switch (opt_type) {
                case LTTNG_CONSUMER_KERNEL:
-                       strcpy(error_sock_path, KCONSUMERD_ERR_SOCK_PATH);
+                       snprintf(error_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH,
+                                       LTTNG_RUNDIR);
                        break;
                case LTTNG_CONSUMER64_UST:
-                       strcpy(error_sock_path, USTCONSUMERD64_ERR_SOCK_PATH);
+                       snprintf(error_sock_path, PATH_MAX,
+                                       USTCONSUMERD64_ERR_SOCK_PATH, LTTNG_RUNDIR);
                        break;
                case LTTNG_CONSUMER32_UST:
-                       strcpy(error_sock_path, USTCONSUMERD32_ERR_SOCK_PATH);
+                       snprintf(error_sock_path, PATH_MAX,
+                                       USTCONSUMERD32_ERR_SOCK_PATH, LTTNG_RUNDIR);
                        break;
                default:
                        WARN("Unknown consumerd type");

diff --git a/lttng-sessiond/main.c b/lttng-sessiond/main.c
index ec45c6676bed50b8934287130011a93b55fef0f8..227f0c2f7f41a0cac7325248d1f5072e6f07494d 100644 (file)
--- a/lttng-sessiond/main.c
+++ b/lttng-sessiond/main.c
@@ -94,6 +94,7 @@ static int opt_sig_parent;
 static int opt_daemon;
 static int is_root;                    /* Set to 1 if the daemon is running as root */
 static pid_t ppid;          /* Parent PID for --sig-parent option */
+static char *rundir;
 
 /* Consumer daemon specific control data */
 static struct consumer_data kconsumer_data = {
@@ -423,19 +424,18 @@ static void cleanup(void)
 
        DBG("Cleaning up");
 
-       if (is_root) {
-               DBG("Removing %s directory", LTTNG_RUNDIR);
-               ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
-               if (ret < 0) {
-                       ERR("asprintf failed. Something is really wrong!");
-               }
+       DBG("Removing %s directory", rundir);
+       ret = asprintf(&cmd, "rm -rf %s", rundir);
+       if (ret < 0) {
+               ERR("asprintf failed. Something is really wrong!");
+       }
 
-               /* Remove lttng run directory */
-               ret = system(cmd);
-               if (ret < 0) {
-                       ERR("Unable to clean " LTTNG_RUNDIR);
-               }
+       /* Remove lttng run directory */
+       ret = system(cmd);
+       if (ret < 0) {
+               ERR("Unable to clean %s", rundir);
        }
+       free(cmd);
 
        DBG("Cleaning up all session");
 
@@ -3996,14 +3996,16 @@ static int create_apps_cmd_pipe(void)
 /*
  * Create the lttng run directory needed for all global sockets and pipe.
  */
-static int create_lttng_rundir(void)
+static int create_lttng_rundir(const char *rundir)
 {
        int ret;
 
-       ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
+       DBG3("Creating LTTng run directory: %s", rundir);
+
+       ret = mkdir(rundir, S_IRWXU | S_IRWXG );
        if (ret < 0) {
                if (errno != EEXIST) {
-                       ERR("Unable to create " LTTNG_RUNDIR);
+                       ERR("Unable to create %s", rundir);
                        goto error;
                } else {
                        ret = 0;
@@ -4018,20 +4020,21 @@ error:
  * Setup sockets and directory needed by the kconsumerd communication with the
  * session daemon.
  */
-static int set_consumer_sockets(struct consumer_data *consumer_data)
+static int set_consumer_sockets(struct consumer_data *consumer_data,
+               const char *rundir)
 {
        int ret;
-       const char *path;
+       char path[PATH_MAX];
 
-       switch (consumer_data->type) {
+    switch (consumer_data->type) {
        case LTTNG_CONSUMER_KERNEL:
-               path = KCONSUMERD_PATH;
+               snprintf(path, PATH_MAX, KCONSUMERD_PATH, rundir);
                break;
        case LTTNG_CONSUMER64_UST:
-               path = USTCONSUMERD64_PATH;
+               snprintf(path, PATH_MAX, USTCONSUMERD64_PATH, rundir);
                break;
        case LTTNG_CONSUMER32_UST:
-               path = USTCONSUMERD32_PATH;
+               snprintf(path, PATH_MAX, USTCONSUMERD32_PATH, rundir);
                break;
        default:
                ERR("Consumer type unknown");
@@ -4039,6 +4042,8 @@ static int set_consumer_sockets(struct consumer_data *consumer_data)
                goto error;
        }
 
+       DBG2("Creating consumer directory: %s", path);
+
        ret = mkdir(path, S_IRWXU | S_IRWXG);
        if (ret < 0) {
                if (errno != EEXIST) {
@@ -4062,7 +4067,7 @@ static int set_consumer_sockets(struct consumer_data *consumer_data)
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
        if (ret < 0) {
                ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
-               perror("chmod");
+               PERROR("chmod");
                goto error;
        }
 
@@ -4189,7 +4194,10 @@ int main(int argc, char **argv)
        is_root = !getuid();
 
        if (is_root) {
-               ret = create_lttng_rundir();
+               rundir = strdup(LTTNG_RUNDIR);
+
+               /* Create global run dir with root access */
+               ret = create_lttng_rundir(rundir);
                if (ret < 0) {
                        goto error;
                }
@@ -4209,6 +4217,17 @@ int main(int argc, char **argv)
                        snprintf(wait_shm_path, PATH_MAX,
                                        DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
                }
+
+               /* Setup kernel consumerd path */
+               snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX,
+                               KCONSUMERD_ERR_SOCK_PATH, rundir);
+               snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX,
+                               KCONSUMERD_CMD_SOCK_PATH, rundir);
+
+               DBG2("Kernel consumer err path: %s",
+                               kconsumer_data.err_unix_sock_path);
+               DBG2("Kernel consumer cmd path: %s",
+                               kconsumer_data.cmd_unix_sock_path);
        } else {
                home_path = get_home_dir();
                if (home_path == NULL) {
@@ -4218,6 +4237,21 @@ int main(int argc, char **argv)
                        goto error;
                }
 
+               /*
+                * Create rundir from home path. This will create something like
+                * $HOME/.lttng
+                */
+               ret = asprintf(&rundir, LTTNG_HOME_RUNDIR, home_path);
+               if (ret < 0) {
+                       ret = -ENOMEM;
+                       goto error;
+               }
+
+               ret = create_lttng_rundir(rundir);
+               if (ret < 0) {
+                       goto error;
+               }
+
                if (strlen(apps_unix_sock_path) == 0) {
                        snprintf(apps_unix_sock_path, PATH_MAX,
                                        DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
@@ -4238,6 +4272,29 @@ int main(int argc, char **argv)
 
        DBG("Client socket path %s", client_unix_sock_path);
        DBG("Application socket path %s", apps_unix_sock_path);
+       DBG("LTTng run directory path: %s", rundir);
+
+       /* 32 bits consumerd path setup */
+       snprintf(ustconsumer32_data.err_unix_sock_path, PATH_MAX,
+                       USTCONSUMERD32_ERR_SOCK_PATH, rundir);
+       snprintf(ustconsumer32_data.cmd_unix_sock_path, PATH_MAX,
+                       USTCONSUMERD32_CMD_SOCK_PATH, rundir);
+
+       DBG2("UST consumer 32 bits err path: %s",
+                       ustconsumer32_data.err_unix_sock_path);
+       DBG2("UST consumer 32 bits cmd path: %s",
+                       ustconsumer32_data.cmd_unix_sock_path);
+
+       /* 64 bits consumerd path setup */
+       snprintf(ustconsumer64_data.err_unix_sock_path, PATH_MAX,
+                       USTCONSUMERD64_ERR_SOCK_PATH, rundir);
+       snprintf(ustconsumer64_data.cmd_unix_sock_path, PATH_MAX,
+                       USTCONSUMERD64_CMD_SOCK_PATH, rundir);
+
+       DBG2("UST consumer 64 bits err path: %s",
+                       ustconsumer64_data.err_unix_sock_path);
+       DBG2("UST consumer 64 bits cmd path: %s",
+                       ustconsumer64_data.cmd_unix_sock_path);
 
        /*
         * See if daemon already exist.
@@ -4260,17 +4317,7 @@ int main(int argc, char **argv)
         * kernel tracer.
         */
        if (is_root) {
-               ret = set_consumer_sockets(&kconsumer_data);
-               if (ret < 0) {
-                       goto exit;
-               }
-
-               ret = set_consumer_sockets(&ustconsumer64_data);
-               if (ret < 0) {
-                       goto exit;
-               }
-
-               ret = set_consumer_sockets(&ustconsumer32_data);
+               ret = set_consumer_sockets(&kconsumer_data, rundir);
                if (ret < 0) {
                        goto exit;
                }
@@ -4282,6 +4329,16 @@ int main(int argc, char **argv)
                set_ulimit();
        }
 
+       ret = set_consumer_sockets(&ustconsumer64_data, rundir);
+       if (ret < 0) {
+               goto exit;
+       }
+
+       ret = set_consumer_sockets(&ustconsumer32_data, rundir);
+       if (ret < 0) {
+               goto exit;
+       }
+
        if ((ret = set_signal_handler()) < 0) {
                goto exit;
        }
@@ -4415,8 +4472,9 @@ exit:
        cleanup();
        rcu_thread_offline();
        rcu_unregister_thread();
-       if (!ret)
+       if (!ret) {
                exit(EXIT_SUCCESS);
+       }
 error:
        exit(EXIT_FAILURE);
 }

diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index 2ed9d002d49f444df38662f3cf26e335d10f0b41..377600f3d2f2347ce52765b43c5fbec19ceddff7 100644 (file)
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -1160,6 +1160,7 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
                char *pathname, struct ust_app *app)
 {
        int ret = 0;
+       mode_t old_umask;
 
        if (ua_sess->metadata == NULL) {
                /* Allocate UST metadata */
@@ -1185,11 +1186,13 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
                        goto error;
                }
 
+               old_umask = umask(0);
                ret = mkdir(ua_sess->path, S_IRWXU | S_IRWXG);
                if (ret < 0) {
                        PERROR("mkdir UST metadata");
                        goto error;
                }
+               umask(old_umask);
 
                ret = snprintf(ua_sess->metadata->pathname, PATH_MAX,
                                "%s/metadata", ua_sess->path);