* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+/* API used by UST components to communicate with each other via sockets. */
+
#define _GNU_SOURCE
#include <sys/types.h>
#include <signal.h>
#include <sys/un.h>
#include <unistd.h>
#include <poll.h>
+#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <execinfo.h>
#include "ustcomm.h"
-#include "localerr.h"
+#include "usterr.h"
+#include "share.h"
+#include "multipoll.h"
#define UNIX_PATH_MAX 108
-#define MSG_MAX 1000
-
-/* 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
- * block.
- */
-
-//static void bt(void)
-//{
-// void *buffer[100];
-// int result;
-//
-// result = backtrace(&buffer, 100);
-// backtrace_symbols_fd(buffer, result, STDERR_FILENO);
-//}
-
-char *strdup_malloc(const char *s)
+static int mkdir_p(const char *path, mode_t mode)
{
- char *retval;
+ const char *path_p;
+ char *tmp;
+
+ int retval = 0;
+ int result;
+ mode_t old_umask;
- if(s == NULL)
- return NULL;
+ tmp = zmalloc(strlen(path) + 1);
+ if (tmp == NULL)
+ return -1;
- retval = (char *) malloc(strlen(s)+1);
+ /* skip first / */
+ path_p = path+1;
- strcpy(retval, s);
+ old_umask = umask(0);
+ 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);
+ umask(old_umask);
return retval;
}
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;
}
+void ustcomm_init_connection(struct ustcomm_connection *conn)
+{
+ conn->recv_buf = NULL;
+ conn->recv_buf_size = 0;
+ conn->recv_buf_alloc = 0;
+}
+
int pid_is_online(pid_t pid) {
- return kill(pid, UST_SIGNAL) != -1;
+ 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;
}
}
/* 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);
- if(src)
- src->fd = fd;
+ /* 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);
+ }
+
+ result = recv(fd, *recv_buf+*recv_buf_size, RECV_INCREMENT, 0);
+ if(result == -1) {
+ if(errno == ECONNRESET) {
+ *recv_buf_size = 0;
+ return 0;
+ }
+ else if(errno == EINTR) {
+ return -1;
+ }
+ else {
+ 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)
list_for_each_entry(conn, &server->connections, list) {
free(deletable_conn);
deletable_conn = conn;
- close(conn->fd);
+ ustcomm_close_app(conn);
list_del(&conn->list);
}
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;
n_fds++;
}
- fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
+ fds = (struct pollfd *) zmalloc(n_fds * sizeof(struct pollfd));
if(fds == NULL) {
- ERR("malloc returned NULL");
+ ERR("zmalloc returned NULL");
return -1;
}
+ conn_table = (struct ustcomm_connection **) zmalloc(n_fds * sizeof(struct ustcomm_connection *));
+ if(conn_table == NULL) {
+ ERR("zmalloc 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;
list_for_each_entry(conn, &server->connections, list) {
fds[idx].fd = conn->fd;
fds[idx].events = POLLIN;
+ conn_table[idx] = conn;
idx++;
}
- while((result = poll(fds, n_fds, timeout)) == -1 && errno == EINTR)
- /* nothing */;
- if(result == -1) {
+ result = poll(fds, n_fds, timeout);
+ if(result == -1 && errno == EINTR) {
+ /* That's ok. ustd receives signals to notify it must shutdown. */
+ retval = -1;
+ goto free_conn_table_return;
+ }
+ else if(result == -1) {
PERROR("poll");
- return -1;
+ retval = -1;
+ goto free_conn_table_return;
+ }
+ else if(result == 0) {
+ retval = 0;
+ goto free_conn_table_return;
}
-
- if(result == 0)
- return 0;
if(fds[0].revents) {
struct ustcomm_connection *newconn;
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));
+ newconn = (struct ustcomm_connection *) zmalloc(sizeof(struct ustcomm_connection));
if(newconn == NULL) {
- ERR("malloc returned NULL");
+ ERR("zmalloc returned NULL");
return -1;
}
+ ustcomm_init_connection(newconn);
newconn->fd = newfd;
list_add(&newconn->list, &server->connections);
for(idx=1; idx<n_fds; idx++) {
if(fds[idx].revents) {
- retval = recv_message_fd(fds[idx].fd, msg, src);
- if(**msg == 0) {
- /* connection finished */
- close(fds[idx].fd);
+ retval = recv_message_conn(conn_table[idx], msg);
+ if(src)
+ src->fd = 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;
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));
}
if(path_out) {
- *path_out = "";
- *path_out = strdupa(addr.sun_path);
+ *path_out = strdup(addr.sun_path);
}
return fd;
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);
- 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;
}
+/* 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");
result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
if(result == -1) {
- PERROR("connect");
+ PERROR("connect (path=%s)", path);
return -1;
}
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;
return ustcomm_connect_path(path, conn, pid);
}
+/* 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;
+
+ /* mkdir mode to 0777 */
+ result = mkdir_p(dir, S_IRWXU | S_IRWXG | S_IRWXO);
+ 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.
*/
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);
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");
}
return retval;
}
-static char *find_tok(char *str)
+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 const char *find_tok(const char *str)
{
while(*str == ' ') {
str++;
return str;
}
-static char *find_sep(char *str)
+static const char *find_sep(const char *str)
{
while(*str != ' ') {
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);
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);
return retval;
}
+/* Callback from multipoll.
+ * Receive a new connection on the listening socket.
+ */
+
+static int process_mp_incoming_conn(void *priv, int fd, short events)
+{
+ struct ustcomm_connection *newconn;
+ struct ustcomm_server *server = (struct ustcomm_server *) priv;
+ int newfd;
+ int result;
+
+ result = newfd = accept(server->listen_fd, NULL, NULL);
+ if(result == -1) {
+ PERROR("accept");
+ return -1;
+ }
+
+ newconn = (struct ustcomm_connection *) zmalloc(sizeof(struct ustcomm_connection));
+ if(newconn == NULL) {
+ ERR("zmalloc returned NULL");
+ return -1;
+ }
+
+ ustcomm_init_connection(newconn);
+ newconn->fd = newfd;
+
+ list_add(&newconn->list, &server->connections);
+
+ return 0;
+}
+
+/* Callback from multipoll.
+ * Receive a message on an existing connection.
+ */
+
+static int process_mp_conn_msg(void *priv, int fd, short revents)
+{
+ struct ustcomm_multipoll_conn_info *mpinfo = (struct ustcomm_multipoll_conn_info *) priv;
+ int result;
+ char *msg;
+ struct ustcomm_source src;
+
+ if(revents) {
+ src.fd = fd;
+
+ result = recv_message_conn(mpinfo->conn, &msg);
+ if(result == -1) {
+ ERR("error in recv_message_conn");
+ }
+
+ else if(result == 0) {
+ /* connection finished */
+ ustcomm_close_app(mpinfo->conn);
+ list_del(&mpinfo->conn->list);
+ free(mpinfo->conn);
+ }
+ else {
+ mpinfo->cb(msg, &src);
+ free(msg);
+ }
+ }
+
+ return 0;
+}
+
+int free_ustcomm_client_poll(void *data)
+{
+ free(data);
+ return 0;
+}
+
+void ustcomm_mp_add_app_clients(struct mpentries *ent, struct ustcomm_app *app, int (*cb)(char *recvbuf, struct ustcomm_source *src))
+{
+ struct ustcomm_connection *conn;
+
+ /* add listener socket */
+ multipoll_add(ent, app->server.listen_fd, POLLIN, process_mp_incoming_conn, &app->server, NULL);
+
+ list_for_each_entry(conn, &app->server.connections, list) {
+ struct ustcomm_multipoll_conn_info *mpinfo = (struct ustcomm_multipoll_conn_info *) zmalloc(sizeof(struct ustcomm_multipoll_conn_info));
+ mpinfo->conn = conn;
+ mpinfo->cb = cb;
+ multipoll_add(ent, conn->fd, POLLIN, process_mp_conn_msg, mpinfo, free_ustcomm_client_poll);
+ }
+}
projects / ust.git / blobdiff