X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libustcomm%2Fustcomm.c;h=8b459df32975499a4c1137ee379fb9d40600b231;hb=34b460e6b2180ef5e42cdc0455b3ac1a0afd912c;hp=e445ed96b55339a52f98bd3c98238bd4bc490206;hpb=811e4b93ba6acb72226a9243ae9a525f444e7e80;p=ust.git diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c index e445ed9..8b459df 100644 --- a/libustcomm/ustcomm.c +++ b/libustcomm/ustcomm.c @@ -1,3 +1,20 @@ +/* Copyright (C) 2009 Pierre-Marc Fournier + * + * 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; either + * version 2.1 of the License, or (at your option) any later version. + * + * 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 + */ + #define _GNU_SOURCE #include #include @@ -6,6 +23,7 @@ #include #include #include +#include #include #include @@ -16,8 +34,6 @@ #include "localerr.h" #define UNIX_PATH_MAX 108 -#define SOCK_DIR "/tmp/socks" -#define UST_SIGNAL SIGIO #define MSG_MAX 1000 @@ -35,96 +51,54 @@ // backtrace_symbols_fd(buffer, result, STDERR_FILENO); //} -static void signal_process(pid_t pid) -{ - int result; - - result = kill(pid, UST_SIGNAL); - if(result == -1) { - PERROR("kill"); - return; - } - - sleep(1); -} - -int send_message_fd(int fd, const char *msg, char **reply) +char *strdup_malloc(const char *s) { - int result; + char *retval; - result = send(fd, msg, strlen(msg), 0); - if(result == -1) { - PERROR("send"); - return -1; - } + if(s == NULL) + return NULL; - if(!reply) - return 0; + retval = (char *) malloc(strlen(s)+1); - *reply = (char *) malloc(MSG_MAX+1); - result = recv(fd, *reply, MSG_MAX, 0); - if(result == -1) { - PERROR("recv"); - return -1; - } - - (*reply)[result] = '\0'; + strcpy(retval, s); - return 0; + return retval; } -int send_message_path(const char *path, const char *msg, char **reply, int signalpid) +static int signal_process(pid_t pid) { - int fd; int result; - struct sockaddr_un addr; - result = fd = socket(PF_UNIX, SOCK_STREAM, 0); + result = kill(pid, UST_SIGNAL); if(result == -1) { - PERROR("socket"); - return -1; - } - - 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"); + PERROR("kill"); return -1; } - if(signalpid >= 0) - signal_process(signalpid); + /* FIXME: should wait in a better way */ + //sleep(1); - result = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); - if(result == -1) { - PERROR("connect"); - return -1; - } - - return send_message_fd(fd, msg, reply); + return 0; } -/* 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 pid_is_online(pid_t pid) { + return kill(pid, UST_SIGNAL) != -1; +} -int send_message(pid_t pid, const char *msg, char **reply) +static int send_message_fd(int fd, const char *msg) { 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"); + result = send(fd, msg, strlen(msg), 0); + if(result == -1) { + PERROR("send"); return -1; } + else if(result == 0) { + return 0; + } - send_message_path(path, msg, reply, pid); - - return 0; + return 1; } /* Called by an app to ask the consumer daemon to connect to it. */ @@ -133,23 +107,55 @@ int ustcomm_request_consumer(pid_t pid, const char *channel) { char path[UNIX_PATH_MAX]; int result; - char *msg; + char *msg=NULL; + int retval = 0; + struct ustcomm_connection conn; + char *explicit_daemon_socket_path; + + 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); + } - result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR); if(result >= UNIX_PATH_MAX) { - fprintf(stderr, "string overflow allocating socket name"); + ERR("string overflow allocating socket name"); return -1; } asprintf(&msg, "collect %d %s", pid, channel); - send_message_path(path, msg, NULL, -1); + /* don't signal it because it's the daemon */ + result = ustcomm_connect_path(path, &conn, -1); + if(result == -1) { + WARN("ustcomm_connect_path failed"); + retval = -1; + goto del_string; + } + + result = ustcomm_send_request(&conn, msg, NULL); + if(result == -1) { + WARN("ustcomm_send_request failed"); + retval = -1; + goto disconnect; + } + + disconnect: + ustcomm_disconnect(&conn); + del_string: free(msg); - return 0; + return retval; } - +/* returns 1 to indicate a message was received + * returns 0 to indicate no message was received (cannot happen) + * returns -1 to indicate an error + */ static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src) { @@ -159,7 +165,7 @@ static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src) result = recv(fd, *msg, MSG_MAX, 0); if(result == -1) { - PERROR("recvfrom"); + PERROR("recv"); return -1; } @@ -170,15 +176,15 @@ static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src) if(src) src->fd = fd; - return 0; + return 1; } int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src) { int result; - result = send_message_fd(src->fd, msg, NULL); - if(result) { + result = send_message_fd(src->fd, msg); + if(result < 0) { ERR("error in send_message_fd"); return -1; } @@ -186,7 +192,31 @@ int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_ return 0; } -int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustcomm_source *src) +/* 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 + * returns 0 to indicate no message was received + * returns -1 to indicate an error + */ + +int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustcomm_source *src, int timeout) { struct pollfd *fds; struct ustcomm_connection *conn; @@ -218,12 +248,16 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco idx++; } - result = poll(fds, n_fds, -1); + while((result = poll(fds, n_fds, timeout)) == -1 && errno == EINTR) + /* nothing */; if(result == -1) { PERROR("poll"); return -1; } + if(result == 0) + return 0; + if(fds[0].revents) { struct ustcomm_connection *newconn; int newfd; @@ -273,17 +307,37 @@ free_fds_return: return retval; } -int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src) +int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src, int timeout) +{ + return ustcomm_recv_message(&ustd->server, msg, src, timeout); +} + +int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout) { - return ustcomm_recv_message(&ustd->server, msg, src); + return ustcomm_recv_message(&app->server, msg, src, timeout); } -int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src) +/* This removes src from the list of active connections of app. + */ + +int ustcomm_app_detach_client(struct ustcomm_app *app, struct ustcomm_source *src) { - return ustcomm_recv_message(&app->server, msg, src); + struct ustcomm_server *server = (struct ustcomm_server *)app; + struct ustcomm_connection *conn; + + list_for_each_entry(conn, &server->connections, list) { + if(conn->fd == src->fd) { + list_del(&conn->list); + goto found; + } + } + + return -1; +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; @@ -325,8 +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; @@ -337,6 +390,109 @@ 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), MSG_NOSIGNAL); + if(result == -1) { + if(errno != ECONNRESET) + PERROR("send"); + return -1; + } + + if(!reply) + return 1; + + *reply = (char *) malloc(MSG_MAX+1); + result = recv(conn->fd, *reply, MSG_MAX, 0); + if(result == -1) { + if(errno != ECONNRESET) + PERROR("recv"); + return -1; + } + else if(result == 0) { + return 0; + } + + (*reply)[result] = '\0'; + + return 1; +} + +int ustcomm_connect_path(const char *path, struct ustcomm_connection *conn, pid_t signalpid) +{ + int fd; + int result; + struct sockaddr_un addr; + + result = fd = socket(PF_UNIX, SOCK_STREAM, 0); + if(result == -1) { + PERROR("socket"); + return -1; + } + + 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; + } + } + + result = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); + if(result == -1) { + PERROR("connect"); + return -1; + } + + conn->fd = fd; + + return 0; +} + +int ustcomm_disconnect(struct ustcomm_connection *conn) +{ + return close(conn->fd); +} + +int ustcomm_connect_app(pid_t pid, struct ustcomm_connection *conn) +{ + int result; + char path[UNIX_PATH_MAX]; + + + result = snprintf(path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid); + if(result >= UNIX_PATH_MAX) { + ERR("string overflow allocating socket name"); + return -1; + } + + return ustcomm_connect_path(path, conn, pid); +} + +/* 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) { int result; @@ -364,31 +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"); + 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)