Create all trace directories and files with client user credentials

[lttng-tools.git] / lttng-sessiond / main.c

diff --git a/lttng-sessiond/main.c b/lttng-sessiond/main.c
index 759b276a650e546e8447e1fd8f6b8442969839af..fbf8d7975330414cf6589d2aa80f707f25dde88e 100644 (file)
--- a/lttng-sessiond/main.c
+++ b/lttng-sessiond/main.c
@@ -512,7 +512,8 @@ static void clean_command_ctx(struct command_ctx **cmd_ctx)
  * Send all stream fds of kernel channel to the consumer.
  */
 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
-               int sock, struct ltt_kernel_channel *channel)
+               int sock, struct ltt_kernel_channel *channel,
+               uid_t uid, gid_t gid)
 {
        int ret;
        struct ltt_kernel_stream *stream;
@@ -544,6 +545,8 @@ static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
                lkm.u.stream.state = stream->state;
                lkm.u.stream.output = channel->channel->attr.output;
                lkm.u.stream.mmap_len = 0;      /* for kernel */
+               lkm.u.stream.uid = uid;
+               lkm.u.stream.gid = gid;
                strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
                lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
                DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
@@ -605,6 +608,8 @@ static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
                lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
                lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
                lkm.u.stream.mmap_len = 0;      /* for kernel */
+               lkm.u.stream.uid = session->uid;
+               lkm.u.stream.gid = session->gid;
                strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
                lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
                DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
@@ -621,7 +626,8 @@ static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
        }
 
        cds_list_for_each_entry(chan, &session->channel_list.head, list) {
-               ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
+               ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
+                               session->uid, session->gid);
                if (ret < 0) {
                        goto error;
                }
@@ -777,7 +783,8 @@ static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
                                 */
                                if (session->kernel_session->consumer_fds_sent == 1) {
                                        ret = send_kconsumer_channel_streams(consumer_data,
-                                                       session->kernel_session->consumer_fd, channel);
+                                                       session->kernel_session->consumer_fd, channel,
+                                                       session->uid, session->gid);
                                        if (ret < 0) {
                                                goto error;
                                        }
@@ -1871,11 +1878,10 @@ error:
  * Create an UST session and add it to the session ust list.
  */
 static int create_ust_session(struct ltt_session *session,
-               struct lttng_domain *domain, struct ucred *creds)
+               struct lttng_domain *domain)
 {
-       int ret;
-       gid_t gid;
        struct ltt_ust_session *lus = NULL;
+       int ret;
 
        switch (domain->type) {
        case LTTNG_DOMAIN_UST:
@@ -1893,16 +1899,8 @@ static int create_ust_session(struct ltt_session *session,
                goto error;
        }
 
-       /*
-        * Get the right group ID. To use the tracing group, the daemon must be
-        * running with root credentials or else it's the user GID used.
-        */
-       gid = allowed_group();
-       if (gid < 0 || !is_root) {
-               gid = creds->gid;
-       }
-
-       ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG, creds->uid, gid);
+       ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
+                       session->uid, session->gid);
        if (ret < 0) {
                if (ret != -EEXIST) {
                        ERR("Trace directory creation error");
@@ -1920,6 +1918,8 @@ static int create_ust_session(struct ltt_session *session,
                ERR("Unknown UST domain on create session %d", domain->type);
                goto error;
        }
+       lus->uid = session->uid;
+       lus->gid = session->gid;
        session->ust_session = lus;
 
        return LTTCOMM_OK;
@@ -1932,11 +1932,9 @@ error:
 /*
  * Create a kernel tracer session then create the default channel.
  */
-static int create_kernel_session(struct ltt_session *session,
-               struct ucred *creds)
+static int create_kernel_session(struct ltt_session *session)
 {
        int ret;
-       gid_t gid;
 
        DBG("Creating kernel session");
 
@@ -1951,23 +1949,16 @@ static int create_kernel_session(struct ltt_session *session,
                session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
        }
 
-       gid = allowed_group();
-       if (gid < 0) {
-               /*
-                * Use GID 0 has a fallback since kernel session is only allowed under
-                * root or the gid of the calling user
-                */
-               is_root ? (gid = 0) : (gid = creds->gid);
-       }
-
        ret = mkdir_recursive(session->kernel_session->trace_path,
-                       S_IRWXU | S_IRWXG, creds->uid, gid);
+                       S_IRWXU | S_IRWXG, session->uid, session->gid);
        if (ret < 0) {
                if (ret != -EEXIST) {
                        ERR("Trace directory creation error");
                        goto error;
                }
        }
+       session->kernel_session->uid = session->uid;
+       session->kernel_session->gid = session->gid;
 
 error:
        return ret;
@@ -2934,11 +2925,11 @@ error:
 /*
  * Command LTTNG_CREATE_SESSION processed by the client thread.
  */
-static int cmd_create_session(char *name, char *path)
+static int cmd_create_session(char *name, char *path, struct ucred *creds)
 {
        int ret;
 
-       ret = session_create(name, path);
+       ret = session_create(name, path, creds->uid, creds->gid);
        if (ret != LTTCOMM_OK) {
                goto error;
        }
@@ -3252,7 +3243,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
                /* Need a session for kernel command */
                if (need_tracing_session) {
                        if (cmd_ctx->session->kernel_session == NULL) {
-                               ret = create_kernel_session(cmd_ctx->session, &cmd_ctx->creds);
+                               ret = create_kernel_session(cmd_ctx->session);
                                if (ret < 0) {
                                        ret = LTTCOMM_KERN_SESS_FAIL;
                                        goto error;
@@ -3279,7 +3270,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
                if (need_tracing_session) {
                        if (cmd_ctx->session->ust_session == NULL) {
                                ret = create_ust_session(cmd_ctx->session,
-                                               &cmd_ctx->lsm->domain, &cmd_ctx->creds);
+                                               &cmd_ctx->lsm->domain);
                                if (ret != LTTCOMM_OK) {
                                        goto error;
                                }
@@ -3421,7 +3412,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
        case LTTNG_CREATE_SESSION:
        {
                ret = cmd_create_session(cmd_ctx->lsm->session.name,
-                               cmd_ctx->lsm->session.path);
+                               cmd_ctx->lsm->session.path, &cmd_ctx->creds);
                break;
        }
        case LTTNG_DESTROY_SESSION: