X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libustcomm%2Fustcomm.c;h=0d2ab339485cb666ba033b24d9896840a7d1c311;hb=da000ba4a6841b1bd55344c75c595aabdd830cd7;hp=0a5ab6aaaf1110d8e66a44b123f81f4d9829c878;hpb=69ba01560f9193dbf4ad2fc8361efb725704807c;p=ust.git diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c index 0a5ab6a..0d2ab33 100644 --- a/libustcomm/ustcomm.c +++ b/libustcomm/ustcomm.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -30,13 +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 @@ -68,156 +68,156 @@ char *strdup_malloc(const char *s) static int signal_process(pid_t pid) { - int result; - - result = kill(pid, UST_SIGNAL); - if(result == -1) { - PERROR("kill"); - return -1; - } - - /* FIXME: should wait in a better way */ - //sleep(1); - return 0; } +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) { - 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 - * 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 1 +#define RECV_INITIAL_BUF_SIZE 10 + +static int recv_message_fd(int fd, char **msg) { int result; + int buf_alloc_size = 0; + char *buf = NULL; + int buf_used_size = 0; - *msg = (char *) malloc(MSG_MAX+1); + buf = malloc(RECV_INITIAL_BUF_SIZE); + buf_alloc_size = RECV_INITIAL_BUF_SIZE; - result = recv(fd, *msg, MSG_MAX, 0); - if(result == -1) { - PERROR("recv"); - return -1; - } + for(;;) { + if(buf_used_size + RECV_INCREMENT > buf_alloc_size) { + char *new_buf; + buf_alloc_size *= 2; + new_buf = (char *) realloc(buf, buf_alloc_size); + if(new_buf == NULL) { + ERR("realloc returned NULL"); + free(buf); + return -1; + } + buf = new_buf; + } - (*msg)[result] = '\0'; - - DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg)); + /* FIXME: this is really inefficient; but with count>1 we would + * need a buffering mechanism */ + result = recv(fd, buf+buf_used_size, RECV_INCREMENT, 0); + if(result == -1) { + free(buf); + if(errno != ECONNRESET) + PERROR("recv"); + return -1; + } + if(result == 0) { + if(buf_used_size) + goto ret; + else { + free(buf); + return 0; + } + } + + buf_used_size += result; + + if(buf[buf_used_size-1] == 0) { + goto ret; + } + } - if(src) - src->fd = fd; +ret: + *msg = buf; + DBG("received message \"%s\"", buf); return 1; + } int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src) @@ -233,6 +233,23 @@ 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 @@ -305,7 +322,10 @@ int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustco for(idx=1; idxfd = fds[idx].fd; + if(**msg == 0) { /* connection finished */ close(fds[idx].fd); @@ -361,7 +381,7 @@ 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; @@ -403,8 +423,7 @@ 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; @@ -415,35 +434,40 @@ 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_fd(conn->fd, 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) +int ustcomm_connect_path(const char *path, struct ustcomm_connection *conn, pid_t signalpid) { int fd; int result; @@ -473,7 +497,7 @@ int ustcomm_connect_path(char *path, struct ustcomm_connection *conn, pid_t sign result = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); if(result == -1) { - PERROR("connect"); + PERROR("connect (path=%s)", path); return -1; } @@ -495,19 +519,49 @@ 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) +static int ensure_dir_exists(const char *dir) { - close(conn->fd); + 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 */ + char buf[200]; + int result; + + result = snprintf(buf, sizeof(buf), "mkdir -p \"%s\"", dir); + if(result >= sizeof(buf)) { + ERR("snprintf buffer overflow"); + return -1; + } + result = system(buf); + if(result != 0) { + ERR("executing command %s", buf); + 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; @@ -519,9 +573,15 @@ 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); @@ -535,34 +595,72 @@ 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 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) +static const char *find_tok(const char *str) { while(*str == ' ') { str++; @@ -574,7 +672,7 @@ 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++; @@ -586,11 +684,11 @@ 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); @@ -615,12 +713,12 @@ 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);