add feature to enable/disable markers
[ust.git] / libustcomm / ustcomm.c
index 0275a736b99a22b7f4b82304f5c289ca2544446d..004cdb001f340e355574c87679f5f82bedf81b41 100644 (file)
@@ -5,6 +5,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
+#include <poll.h>
 
 #include <stdio.h>
 #include <stdlib.h>
 
 #define MSG_MAX 1000
 
-static void bt(void)
+/* 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)
 {
-       void *buffer[100];
-       int result;
+       char *retval;
+
+       if(s == NULL)
+               return NULL;
+
+       retval = (char *) malloc(strlen(s)+1);
+
+       strcpy(retval, s);
 
-       result = backtrace(&buffer, 100);
-       backtrace_symbols_fd(buffer, result, STDERR_FILENO);
+       return retval;
 }
 
-static void signal_process(pid_t pid)
+static int signal_process(pid_t pid)
 {
        int result;
 
        result = kill(pid, UST_SIGNAL);
        if(result == -1) {
                PERROR("kill");
-               return;
+               return -1;
+       }
+
+       /* FIXME: should wait in a better way */
+       //sleep(1);
+
+       return 0;
+}
+
+static int send_message_fd(int fd, const char *msg)
+{
+       int result;
+
+       result = send(fd, msg, strlen(msg), 0);
+       if(result == -1) {
+               PERROR("send");
+               return -1;
+       }
+       else if(result == 0) {
+               return 0;
        }
 
-       sleep(1);
+       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;
 }
 
-int send_message_path(const char *path, const char *msg, char **reply, int signalpid)
+static int send_message_path(const char *path, const char *msg, int signalpid)
 {
        int fd;
        int result;
        struct sockaddr_un addr;
 
-       result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+       result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
        if(result == -1) {
                PERROR("socket");
                return -1;
@@ -62,51 +115,44 @@ int send_message_path(const char *path, const char *msg, char **reply, int signa
                return -1;
        }
 
-       if(signalpid >= 0)
-               signal_process(signalpid);
-
-       result = sendto(fd, msg, strlen(msg), 0, (struct sockaddr *)&addr, sizeof(addr));
-       if(result == -1) {
-               PERROR("sendto");
-               return -1;
+       if(signalpid >= 0) {
+               result = signal_process(signalpid);
+               if(result == -1) {
+                       ERR("could not signal process");
+                       return -1;
+               }
        }
 
-       if(!reply)
-               return 0;
-
-       *reply = (char *) malloc(MSG_MAX+1);
-       result = recvfrom(fd, *reply, MSG_MAX, 0, NULL, NULL);
+       result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
        if(result == -1) {
-               PERROR("recvfrom");
+               PERROR("connect");
                return -1;
        }
-       
-       (*reply)[result] = '\0';
 
-       return 0;
+       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_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;
-}
+///* 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. */
 
@@ -124,21 +170,26 @@ int ustcomm_request_consumer(pid_t pid, const char *channel)
 
        asprintf(&msg, "collect %d %s", pid, channel); 
 
-       send_message_path(path, msg, NULL, pid);
+       send_message_path(path, msg, -1);
        free(msg);
 
        return 0;
 }
 
-static int recv_message_fd(int fd, char **msg)
+/* 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)
 {
        int result;
-       struct sockaddr_un addr;
 
        *msg = (char *) malloc(MSG_MAX+1);
-       result = recvfrom(fd, *msg, MSG_MAX, 0, NULL, NULL);
+
+       result = recv(fd, *msg, MSG_MAX, 0);
        if(result == -1) {
-               PERROR("recvfrom");
+               PERROR("recv");
                return -1;
        }
 
@@ -146,19 +197,150 @@ static int recv_message_fd(int fd, char **msg)
        
        DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg));
 
-       bt();
+       if(src)
+               src->fd = fd;
+
+       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);
+       if(result < 0) {
+               ERR("error in send_message_fd");
+               return -1;
+       }
 
        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;
+       int result;
+       int retval;
+
+       for(;;) {
+               int idx = 0;
+               int n_fds = 1;
+
+               list_for_each_entry(conn, &server->connections, list) {
+                       n_fds++;
+               }
+
+               fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
+               if(fds == NULL) {
+                       ERR("malloc returned NULL");
+                       return -1;
+               }
+
+               /* special idx 0 is for listening socket */
+               fds[idx].fd = server->listen_fd;
+               fds[idx].events = POLLIN;
+               idx++;
+
+               list_for_each_entry(conn, &server->connections, list) {
+                       fds[idx].fd = conn->fd;
+                       fds[idx].events = POLLIN;
+                       idx++;
+               }
+
+               result = poll(fds, n_fds, timeout);
+               if(result == -1) {
+                       PERROR("poll");
+                       return -1;
+               }
+
+               if(result == 0)
+                       return 0;
+
+               if(fds[0].revents) {
+                       struct ustcomm_connection *newconn;
+                       int newfd;
+
+                       result = newfd = accept(server->listen_fd, NULL, NULL);
+                       if(result == -1) {
+                               PERROR("accept");
+                               return -1;
+                       }
+
+                       newconn = (struct ustcomm_connection *) malloc(sizeof(struct ustcomm_connection));
+                       if(newconn == NULL) {
+                               ERR("malloc returned NULL");
+                               return -1;
+                       }
+
+                       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);
+
+                                       list_for_each_entry(conn, &server->connections, list) {
+                                               if(conn->fd == fds[idx].fd) {
+                                                       list_del(&conn->list);
+                                                       break;
+                                               }
+                                       }
+                               }
+                               else {
+                                       goto free_fds_return;
+                               }
+                       }
+               }
+
+               free(fds);
+       }
+
+free_fds_return:
+       free(fds);
+       return retval;
+}
+
+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_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg)
+int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout)
 {
-       return recv_message_fd(ustd->fd, msg);
+       return ustcomm_recv_message(&app->server, msg, src, timeout);
 }
 
-int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg)
+/* 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 recv_message_fd(app->fd, msg);
+       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)
@@ -168,7 +350,7 @@ static int init_named_socket(char *name, char **path_out)
 
        struct sockaddr_un addr;
        
-       result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+       result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
        if(result == -1) {
                PERROR("socket");
                return -1;
@@ -179,12 +361,29 @@ static int init_named_socket(char *name, char **path_out)
        strncpy(addr.sun_path, name, UNIX_PATH_MAX);
        addr.sun_path[UNIX_PATH_MAX-1] = '\0';
 
+       result = access(name, F_OK);
+       if(result == 0) {
+               /* file exists */
+               result = unlink(name);
+               if(result == -1) {
+                       PERROR("unlink of socket file");
+                       goto close_sock;
+               }
+               WARN("socket already exists; overwriting");
+       }
+
        result = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
        if(result == -1) {
                PERROR("bind");
                goto close_sock;
        }
 
+       result = listen(fd, 1);
+       if(result == -1) {
+               PERROR("listen");
+               goto close_sock;
+       }
+
        if(path_out) {
                *path_out = "";
                *path_out = strdupa(addr.sun_path);
@@ -198,6 +397,99 @@ static int init_named_socket(char *name, char **path_out)
        return -1;
 }
 
+int ustcomm_send_request(struct ustcomm_connection *conn, char *req, char **reply)
+{
+       int result;
+
+       result = send(conn->fd, req, strlen(req), 0);
+       if(result == -1) {
+               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) {
+               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 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) {
+               fprintf(stderr, "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;
+}
+
 int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle)
 {
        int result;
@@ -209,12 +501,15 @@ int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle)
                return -1;
        }
 
-       handle->fd = init_named_socket(name, &(handle->socketpath));
-       if(handle->fd < 0) {
+       handle->server.listen_fd = init_named_socket(name, &(handle->server.socketpath));
+       if(handle->server.listen_fd < 0) {
+               ERR("error initializing named socket");
                goto free_name;
        }
        free(name);
 
+       INIT_LIST_HEAD(&handle->server.connections);
+
        return 0;
 
 free_name:
@@ -224,9 +519,112 @@ free_name:
 
 int ustcomm_init_ustd(struct ustcomm_ustd *handle)
 {
-       handle->fd = init_named_socket("ustd", &handle->socketpath);
-       if(handle->fd < 0)
-               return handle->fd;
+       int result;
+       char *name;
+
+       result = asprintf(&name, "%s/%s", SOCK_DIR, "ustd");
+       if(result >= UNIX_PATH_MAX) {
+               ERR("string overflow allocating socket name");
+               return -1;
+       }
+
+       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);
+               goto free_name;
+       }
+       free(name);
+
+       INIT_LIST_HEAD(&handle->server.connections);
 
        return 0;
+
+free_name:
+       free(name);
+       return -1;
+}
+
+static char *find_tok(char *str)
+{
+       while(*str == ' ') {
+               str++;
+
+               if(*str == 0)
+                       return NULL;
+       }
+
+       return str;
+}
+
+static char *find_sep(char *str)
+{
+       while(*str != ' ') {
+               str++;
+
+               if(*str == 0)
+                       break;
+       }
+
+       return str;
+}
+
+int nth_token_is(char *str, char *token, int tok_no)
+{
+       int i;
+       char *start;
+       char *end;
+
+       for(i=0; i<=tok_no; i++) {
+               str = find_tok(str);
+               if(str == NULL)
+                       return -1;
+
+               start = str;
+
+               str = find_sep(str);
+               if(str == NULL)
+                       return -1;
+
+               end = str;
+       }
+
+       if(end-start != strlen(token))
+               return 0;
+
+       if(strncmp(start, token, end-start))
+               return 0;
+
+       return 1;
 }
+
+char *nth_token(char *str, int tok_no)
+{
+       static char *retval = NULL;
+       int i;
+       char *start;
+       char *end;
+
+       for(i=0; i<=tok_no; i++) {
+               str = find_tok(str);
+               if(str == NULL)
+                       return NULL;
+
+               start = str;
+
+               str = find_sep(str);
+               if(str == NULL)
+                       return NULL;
+
+               end = str;
+       }
+
+       if(retval) {
+               free(retval);
+               retval = NULL;
+       }
+
+       asprintf(&retval, "%.*s", (int)(end-start), start);
+
+       return retval;
+}
+
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