X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libustcomm%2Fustcomm.c;h=cb72db65733eb5353c7d10a74018ff856874c648;hb=69c37f741b8bd8aea95019e1debf5e3bfa9d7fff;hp=d6e5346d26e468a73addc6b6fc8eca369d6e58b3;hpb=8cefc1450e2d929de5d2878518e7b8b2b77ff755;p=ust.git diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c index d6e5346..cb72db6 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 @@ -13,13 +31,12 @@ #include #include "ustcomm.h" -#include "localerr.h" +#include "usterr.h" +#include "share.h" #define UNIX_PATH_MAX 108 -#define SOCK_DIR "/tmp/socks" -#define UST_SIGNAL SIGIO -#define MSG_MAX 1000 +#define MSG_MAX 10000 /* FIXME: ustcomm blocks on message sending, which might be problematic in * some cases. Fix the poll() usage so sends are buffered until they don't @@ -35,6 +52,55 @@ // backtrace_symbols_fd(buffer, result, STDERR_FILENO); //} +static int mkdir_p(const char *path, mode_t mode) +{ + const char *path_p; + char *tmp; + + int retval = 0; + int result; + + tmp = malloc(strlen(path) + 1); + if (tmp == NULL) + return -1; + + /* skip first / */ + path_p = path+1; + + for(;;) { + while (*path_p != '/') { + if(*path_p == 0) + break; + ++path_p; + } + if (*path_p == '/') { + strncpy(tmp, path, path_p - path); + tmp[path_p-path] = '\0'; + if (tmp[path_p - path - 1] != '/') { + result = mkdir(tmp, mode); + if(result == -1) { + if (!(errno == EEXIST || errno == EACCES || errno == EROFS)) { + /* Then this is a real error */ + retval = -1; + break; + } + } + } + /* pass / */ + path_p++; + } else { + /* last component */ + result = mkdir(path, mode); + if (result == -1) + retval = -1; + break; + } + } + + free(tmp); + return retval; +} + char *strdup_malloc(const char *s) { char *retval; @@ -49,151 +115,188 @@ char *strdup_malloc(const char *s) return retval; } -static void signal_process(pid_t pid) +static int signal_process(pid_t pid) { - int result; + return 0; +} - result = kill(pid, UST_SIGNAL); - if(result == -1) { - PERROR("kill"); - return; - } +void ustcomm_init_connection(struct ustcomm_connection *conn) +{ + conn->recv_buf = NULL; + conn->recv_buf_size = 0; + conn->recv_buf_alloc = 0; +} - /* FIXME: should wait in a better way */ - sleep(1); +int pid_is_online(pid_t pid) { + return 1; } +/* Send a message + * + * @fd: file descriptor to send to + * @msg: a null-terminated string containing the message to send + * + * Return value: + * -1: error + * 0: connection closed + * 1: success + */ + static int send_message_fd(int fd, const char *msg) { int result; - result = send(fd, msg, strlen(msg), 0); + /* Send including the final \0 */ + result = patient_send(fd, msg, strlen(msg)+1, MSG_NOSIGNAL); if(result == -1) { - PERROR("send"); + if(errno != EPIPE) + PERROR("send"); return -1; } else if(result == 0) { return 0; } + DBG("sent message \"%s\"", 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) - signal_process(signalpid); + 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 - * returns 0 to indicate no message was received (cannot happen) + * returns 0 to indicate no message was received (end of stream) * returns -1 to indicate an error */ -static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src) +#define RECV_INCREMENT 1000 +#define RECV_INITIAL_BUF_SIZE 10 + +static int recv_message_fd(int fd, char **recv_buf, int *recv_buf_size, int *recv_buf_alloc, char **msg) { int result; - *msg = (char *) malloc(MSG_MAX+1); + /* 1. Check if there is a message in the buf */ + /* 2. If not, do: + 2.1 receive chunk and put it in buffer + 2.2 process full message if there is one + -- while no message arrived + */ - result = recv(fd, *msg, MSG_MAX, 0); - if(result == -1) { - PERROR("recv"); - return -1; - } + for(;;) { + int i; + int nulfound = 0; + + /* Search for full message in buffer */ + for(i=0; i<*recv_buf_size; i++) { + if((*recv_buf)[i] == '\0') { + nulfound = 1; + break; + } + } - (*msg)[result] = '\0'; - - DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg)); + /* Process found message */ + if(nulfound == 1) { + char *newbuf; + + if(i == 0) { + /* problem */ + WARN("received empty message"); + } + *msg = strndup(*recv_buf, i); + + /* Remove processed message from buffer */ + newbuf = (char *) malloc(*recv_buf_size - (i+1)); + memcpy(newbuf, *recv_buf + (i+1), *recv_buf_size - (i+1)); + free(*recv_buf); + *recv_buf = newbuf; + *recv_buf_size -= (i+1); + *recv_buf_alloc -= (i+1); + + return 1; + } + + /* Receive a chunk from the fd */ + if(*recv_buf_alloc - *recv_buf_size < RECV_INCREMENT) { + *recv_buf_alloc += RECV_INCREMENT - (*recv_buf_alloc - *recv_buf_size); + *recv_buf = (char *) realloc(*recv_buf, *recv_buf_alloc); + } - if(src) - src->fd = fd; + result = recv(fd, *recv_buf+*recv_buf_size, RECV_INCREMENT, 0); + if(result == -1) { + if(errno == ECONNRESET) { + *recv_buf_size = 0; + return 0; + } + /* real error */ + PERROR("recv"); + return -1; + } + if(result == 0) { + return 0; + } + *recv_buf_size += result; + + /* Go back to the beginning to check if there is a full message in the buffer */ + } + + DBG("received message \"%s\"", *recv_buf); return 1; + +} + +static int recv_message_conn(struct ustcomm_connection *conn, char **msg) +{ + return recv_message_fd(conn->fd, &conn->recv_buf, &conn->recv_buf_size, &conn->recv_buf_alloc, msg); } int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src) @@ -209,6 +312,23 @@ 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; + ustcomm_close_app(conn); + list_del(&conn->list); + } + + return 0; +} + /* @timeout: max blocking time in milliseconds, -1 means infinity * * returns 1 to indicate a message was received @@ -219,6 +339,7 @@ int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustcomm_source *src, int timeout) { struct pollfd *fds; + struct ustcomm_connection **conn_table; struct ustcomm_connection *conn; int result; int retval; @@ -237,6 +358,13 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco return -1; } + conn_table = (struct ustcomm_connection **) malloc(n_fds * sizeof(struct ustcomm_connection *)); + if(conn_table == NULL) { + ERR("malloc returned NULL"); + retval = -1; + goto free_fds_return; + } + /* special idx 0 is for listening socket */ fds[idx].fd = server->listen_fd; fds[idx].events = POLLIN; @@ -245,17 +373,22 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco list_for_each_entry(conn, &server->connections, list) { fds[idx].fd = conn->fd; fds[idx].events = POLLIN; + conn_table[idx] = conn; idx++; } - result = poll(fds, n_fds, timeout); + while((result = poll(fds, n_fds, timeout)) == -1 && errno == EINTR) + /* nothing */; if(result == -1) { PERROR("poll"); - return -1; + retval = -1; + goto free_conn_table_return; } - if(result == 0) - return 0; + if(result == 0) { + retval = 0; + goto free_conn_table_return; + } if(fds[0].revents) { struct ustcomm_connection *newconn; @@ -264,7 +397,8 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco result = newfd = accept(server->listen_fd, NULL, NULL); if(result == -1) { PERROR("accept"); - return -1; + retval = -1; + goto free_conn_table_return; } newconn = (struct ustcomm_connection *) malloc(sizeof(struct ustcomm_connection)); @@ -273,6 +407,7 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco return -1; } + ustcomm_init_connection(newconn); newconn->fd = newfd; list_add(&newconn->list, &server->connections); @@ -280,27 +415,33 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco for(idx=1; idxfd = fds[idx].fd; + if(retval == 0) { + /* connection finished */ list_for_each_entry(conn, &server->connections, list) { if(conn->fd == fds[idx].fd) { + ustcomm_close_app(conn); list_del(&conn->list); + free(conn); break; } } } else { - goto free_fds_return; + goto free_conn_table_return; } } } free(fds); + free(conn_table); } +free_conn_table_return: + free(conn_table); free_fds_return: free(fds); return retval; @@ -336,7 +477,7 @@ 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; @@ -362,7 +503,7 @@ static int init_named_socket(char *name, char **path_out) PERROR("unlink of socket file"); goto close_sock; } - WARN("socket already exists; overwriting"); + DBG("socket already exists; overwriting"); } result = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); @@ -378,8 +519,7 @@ 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; @@ -390,40 +530,52 @@ static int init_named_socket(char *name, char **path_out) return -1; } -int ustcomm_send_request(struct ustcomm_connection *conn, char *req, char **reply) +/* + * 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); - if(result == -1) { - PERROR("send"); - return -1; - } + /* Send including the final \0 */ + result = send_message_fd(conn->fd, req); + if(result != 1) + return result; if(!reply) return 1; - *reply = (char *) malloc(MSG_MAX+1); - result = recv(conn->fd, *reply, MSG_MAX, 0); + result = recv_message_conn(conn, reply); if(result == -1) { - PERROR("recv"); return -1; } else if(result == 0) { return 0; } - (*reply)[result] = '\0'; - return 1; } -int ustcomm_connect_path(char *path, struct ustcomm_connection *conn, pid_t signalpid) +/* Return value: + * 0: success + * -1: error + */ + +int ustcomm_connect_path(const char *path, struct ustcomm_connection *conn, pid_t signalpid) { int fd; int result; struct sockaddr_un addr; + ustcomm_init_connection(conn); + result = fd = socket(PF_UNIX, SOCK_STREAM, 0); if(result == -1) { PERROR("socket"); @@ -438,12 +590,17 @@ int ustcomm_connect_path(char *path, struct ustcomm_connection *conn, pid_t sign return -1; } - if(signalpid >= 0) - signal_process(signalpid); + 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"); + PERROR("connect (path=%s)", path); return -1; } @@ -457,6 +614,13 @@ int ustcomm_disconnect(struct ustcomm_connection *conn) return close(conn->fd); } +/* Open a connection to a traceable app. + * + * Return value: + * 0: success + * -1: error + */ + int ustcomm_connect_app(pid_t pid, struct ustcomm_connection *conn) { int result; @@ -465,19 +629,56 @@ 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 a connection to a traceable app. It frees the + * resources. It however does not free the + * ustcomm_connection itself. + */ + +int ustcomm_close_app(struct ustcomm_connection *conn) { close(conn->fd); + free(conn->recv_buf); + + return 0; +} + +static int ensure_dir_exists(const char *dir) +{ + struct stat st; + int result; + + if(!strcmp(dir, "")) + return -1; + + result = stat(dir, &st); + if(result == -1 && errno != ENOENT) { + return -1; + } + else if(result == -1) { + /* ENOENT */ + int result; + + result = mkdir_p(dir, 0777); + if(result != 0) { + ERR("executing in recursive creation of directory %s", dir); + return -1; + } + } + 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) { int result; @@ -489,9 +690,15 @@ int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle) return -1; } + result = ensure_dir_exists(SOCK_DIR); + if(result == -1) { + ERR("Unable to create socket directory %s", SOCK_DIR); + return -1; + } + 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 (%s). Check that directory exists and that it is writable.", name); goto free_name; } free(name); @@ -505,34 +712,96 @@ 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 { + int result; + + /* Only check if socket dir exists if we are using the default directory */ + result = ensure_dir_exists(SOCK_DIR); + if(result == -1) { + ERR("Unable to create socket directory %s", SOCK_DIR); + return -1; + } + + 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; +} + +static void ustcomm_fini_server(struct ustcomm_server *server, int keep_socket_file) +{ + int result; + struct stat st; + + if(!keep_socket_file) { + /* Destroy socket */ + result = stat(server->socketpath, &st); + if(result == -1) { + PERROR("stat (%s)", 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(server->socketpath); + if(result == -1) { + PERROR("unlink"); + } + } + + free(server->socketpath); + + result = close(server->listen_fd); + if(result == -1) { + PERROR("close"); + return; + } +} + +/* Free a traceable application server */ + +void ustcomm_fini_app(struct ustcomm_app *handle, int keep_socket_file) +{ + ustcomm_fini_server(&handle->server, keep_socket_file); +} + +/* Free a ustd server */ + +void ustcomm_fini_ustd(struct ustcomm_ustd *handle) +{ + ustcomm_fini_server(&handle->server, 0); } -static char *find_tok(char *str) +static const char *find_tok(const char *str) { while(*str == ' ') { str++; @@ -544,7 +813,7 @@ static char *find_tok(char *str) return str; } -static char *find_sep(char *str) +static const char *find_sep(const char *str) { while(*str != ' ') { str++; @@ -556,11 +825,11 @@ static char *find_sep(char *str) return str; } -int nth_token_is(char *str, char *token, int tok_no) +int nth_token_is(const char *str, const char *token, int tok_no) { int i; - char *start; - char *end; + const char *start; + const char *end; for(i=0; i<=tok_no; i++) { str = find_tok(str); @@ -585,12 +854,12 @@ int nth_token_is(char *str, char *token, int tok_no) return 1; } -char *nth_token(char *str, int tok_no) +char *nth_token(const char *str, int tok_no) { static char *retval = NULL; int i; - char *start; - char *end; + const char *start; + const char *end; for(i=0; i<=tok_no; i++) { str = find_tok(str);