X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libustcomm%2Fustcomm.c;h=8b459df32975499a4c1137ee379fb9d40600b231;hb=34b460e6b2180ef5e42cdc0455b3ac1a0afd912c;hp=e8199b3aaf5c6b70eadb2bd2fb01083684ae9c36;hpb=772030fed323e388da467735cf4b5e8781acb710;p=ust.git diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c index e8199b3..8b459df 100644 --- a/libustcomm/ustcomm.c +++ b/libustcomm/ustcomm.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -98,101 +99,57 @@ static int send_message_fd(int fd, const char *msg) } return 1; - -// *reply = (char *) malloc(MSG_MAX+1); -// result = recv(fd, *reply, MSG_MAX, 0); -// if(result == -1) { -// PERROR("recv"); -// return -1; -// } -// else if(result == 0) { -// return 0; -// } -// -// (*reply)[result] = '\0'; -// -// return 1; } -static int send_message_path(const char *path, const char *msg, int signalpid) +/* Called by an app to ask the consumer daemon to connect to it. */ + +int ustcomm_request_consumer(pid_t pid, const char *channel) { - int fd; + char path[UNIX_PATH_MAX]; int result; - struct sockaddr_un addr; + char *msg=NULL; + int retval = 0; + struct ustcomm_connection conn; + char *explicit_daemon_socket_path; - result = fd = socket(PF_UNIX, SOCK_STREAM, 0); - if(result == -1) { - PERROR("socket"); - return -1; + explicit_daemon_socket_path = getenv("UST_DAEMON_SOCKET"); + if(explicit_daemon_socket_path) { + /* user specified explicitly a socket path */ + result = snprintf(path, UNIX_PATH_MAX, "%s", explicit_daemon_socket_path); + } + else { + /* just use the default path */ + result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR); } - addr.sun_family = AF_UNIX; - - result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s", path); if(result >= UNIX_PATH_MAX) { ERR("string overflow allocating socket name"); return -1; } - if(signalpid >= 0) { - result = signal_process(signalpid); - if(result == -1) { - ERR("could not signal process"); - return -1; - } - } + asprintf(&msg, "collect %d %s", pid, channel); - result = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); + /* don't signal it because it's the daemon */ + result = ustcomm_connect_path(path, &conn, -1); if(result == -1) { - PERROR("connect"); - return -1; + WARN("ustcomm_connect_path failed"); + retval = -1; + goto del_string; } - return send_message_fd(fd, msg); -} - -///* pid: the pid of the trace process that must receive the msg -// msg: pointer to a null-terminated message to send -// reply: location where to put the null-terminated string of the reply; -// it must be free'd after usage -// */ -// -//int send_message_pid(pid_t pid, const char *msg, char **reply) -//{ -// int result; -// char path[UNIX_PATH_MAX]; -// -// result = snprintf(path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid); -// if(result >= UNIX_PATH_MAX) { -// fprintf(stderr, "string overflow allocating socket name"); -// return -1; -// } -// -// send_message_path(path, msg, reply, pid); -// -// return 0; -//} - -/* Called by an app to ask the consumer daemon to connect to it. */ - -int ustcomm_request_consumer(pid_t pid, const char *channel) -{ - char path[UNIX_PATH_MAX]; - int result; - char *msg; - - result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR); - if(result >= UNIX_PATH_MAX) { - fprintf(stderr, "string overflow allocating socket name"); - return -1; + result = ustcomm_send_request(&conn, msg, NULL); + if(result == -1) { + WARN("ustcomm_send_request failed"); + retval = -1; + goto disconnect; } - asprintf(&msg, "collect %d %s", pid, channel); - - send_message_path(path, msg, -1); + disconnect: + ustcomm_disconnect(&conn); + del_string: free(msg); - return 0; + return retval; } /* returns 1 to indicate a message was received @@ -235,6 +192,23 @@ int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_ return 0; } +/* Called after a fork. */ + +int ustcomm_close_all_connections(struct ustcomm_server *server) +{ + struct ustcomm_connection *conn; + struct ustcomm_connection *deletable_conn = NULL; + + list_for_each_entry(conn, &server->connections, list) { + free(deletable_conn); + deletable_conn = conn; + close(conn->fd); + list_del(&conn->list); + } + + return 0; +} + /* @timeout: max blocking time in milliseconds, -1 means infinity * * returns 1 to indicate a message was received @@ -363,7 +337,7 @@ found: return src->fd; } -static int init_named_socket(char *name, char **path_out) +static int init_named_socket(const char *name, char **path_out) { int result; int fd; @@ -405,8 +379,7 @@ static int init_named_socket(char *name, char **path_out) } if(path_out) { - *path_out = ""; - *path_out = strdupa(addr.sun_path); + *path_out = strdup(addr.sun_path); } return fd; @@ -417,13 +390,24 @@ static int init_named_socket(char *name, char **path_out) return -1; } +/* + * Return value: + * 0: Success, but no reply because recv() returned 0 + * 1: Success + * -1: Error + * + * On error, the error message is printed, except on + * ECONNRESET, which is normal when the application dies. + */ + int ustcomm_send_request(struct ustcomm_connection *conn, const char *req, char **reply) { int result; - result = send(conn->fd, req, strlen(req), 0); + result = send(conn->fd, req, strlen(req), MSG_NOSIGNAL); if(result == -1) { - PERROR("send"); + if(errno != ECONNRESET) + PERROR("send"); return -1; } @@ -433,7 +417,8 @@ int ustcomm_send_request(struct ustcomm_connection *conn, const char *req, char *reply = (char *) malloc(MSG_MAX+1); result = recv(conn->fd, *reply, MSG_MAX, 0); if(result == -1) { - PERROR("recv"); + if(errno != ECONNRESET) + PERROR("recv"); return -1; } else if(result == 0) { @@ -445,7 +430,7 @@ int ustcomm_send_request(struct ustcomm_connection *conn, const char *req, char return 1; } -int ustcomm_connect_path(char *path, struct ustcomm_connection *conn, pid_t signalpid) +int ustcomm_connect_path(const char *path, struct ustcomm_connection *conn, pid_t signalpid) { int fd; int result; @@ -497,18 +482,16 @@ int ustcomm_connect_app(pid_t pid, struct ustcomm_connection *conn) result = snprintf(path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid); if(result >= UNIX_PATH_MAX) { - fprintf(stderr, "string overflow allocating socket name"); + ERR("string overflow allocating socket name"); return -1; } return ustcomm_connect_path(path, conn, pid); } -int ustcomm_disconnect_app(struct ustcomm_connection *conn) -{ - close(conn->fd); - return 0; -} +/* Called by an application to initialize its server so daemons can + * connect to it. + */ int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle) { @@ -537,31 +520,60 @@ free_name: return -1; } -int ustcomm_init_ustd(struct ustcomm_ustd *handle) +/* Used by the daemon to initialize its server so applications + * can connect to it. + */ + +int ustcomm_init_ustd(struct ustcomm_ustd *handle, const char *sock_path) { - int result; char *name; + int retval = 0; - result = asprintf(&name, "%s/%s", SOCK_DIR, "ustd"); - if(result >= UNIX_PATH_MAX) { - ERR("string overflow allocating socket name"); - return -1; + if(sock_path) { + asprintf(&name, "%s", sock_path); + } + else { + asprintf(&name, "%s/%s", SOCK_DIR, "ustd"); } handle->server.listen_fd = init_named_socket(name, &handle->server.socketpath); if(handle->server.listen_fd < 0) { ERR("error initializing named socket at %s", name); + retval = -1; goto free_name; } - free(name); INIT_LIST_HEAD(&handle->server.connections); - return 0; - free_name: free(name); - return -1; + + return retval; +} + +void ustcomm_fini_app(struct ustcomm_app *handle) +{ + int result; + struct stat st; + + /* Destroy socket */ + result = stat(handle->server.socketpath, &st); + if(result == -1) { + PERROR("stat (%s)", handle->server.socketpath); + return; + } + + /* Paranoid check before deleting. */ + result = S_ISSOCK(st.st_mode); + if(!result) { + ERR("The socket we are about to delete is not a socket."); + return; + } + + result = unlink(handle->server.socketpath); + if(result == -1) { + PERROR("unlink"); + } } static char *find_tok(char *str)