diff options
Diffstat (limited to '')
| -rw-r--r-- | src/mds-vt.c | 136 | ||||
| -rw-r--r-- | src/mds-vt.h | 14 |
2 files changed, 138 insertions, 12 deletions
diff --git a/src/mds-vt.c b/src/mds-vt.c index 8b2f276..8948c97 100644 --- a/src/mds-vt.c +++ b/src/mds-vt.c @@ -33,7 +33,8 @@ #include <fcntl.h> #include <unistd.h> #include <signal.h> -#define reconnect_to_display() -1 +#define reconnect_fd_to_display(fd) -1 +#define reconnect_to_display() reconnect_fd_to_display(&socket_fd) @@ -104,6 +105,26 @@ static volatile sig_atomic_t switching_vt = 0; */ static char vtfile_path[PATH_MAX]; +/** + * The file descriptor for the secondary connection to the display + */ +static int secondary_socket_fd; + +/** + * Whether the secondary thread has been started + */ +static int secondary_thread_started = 0; + +/** + * The secondary thread + */ +static pthread_t secondary_thread; + +/** + * Whether the secondary thread failed + */ +static volatile sig_atomic_t secondary_thread_failed = 0; + /** @@ -186,6 +207,7 @@ int initialise_server(void) { struct vt_mode mode; char* display_env; + int primary_socket_fd; const char* const message = "Command: intercept\n" "Message ID: 0\n" @@ -193,6 +215,19 @@ int initialise_server(void) "\n" "Command: get-vt\n" "Command: configure-vt\n"; + const char* const secondary_message = + "Command: intercept\n" + "Message ID: 0\n" + "Priority: -4611686018427387904\n" /* −2⁶² */ + "Length: 22\n" + "\n" + "Command: switching-vt\n"; + + primary_socket_fd = socket_fd; + if (connect_to_display()) + return 1; + secondary_socket_fd = socket_fd; + socket_fd = primary_socket_fd; display_env = getenv("MDS_DISPLAY"); display_env = display_env ? strchr(display_env, ':') : NULL; @@ -223,7 +258,9 @@ int initialise_server(void) fail_if (vt_is_active < 0); } - if (full_send(message, strlen(message))) + if (full_send(secondary_socket_fd, secondary_message, strlen(secondary_message))) + return 1; + if (full_send(socket_fd, message, strlen(message))) return 1; fail_if (server_initialised() < 0); fail_if (mds_message_initialise(&received)); @@ -267,6 +304,10 @@ int postinitialise_server(void) return 1; } connected = 1; + + if ((errno = pthread_create(&secondary_thread, NULL, secondary_loop, NULL))) + return 1; + return 0; } @@ -281,7 +322,7 @@ int postinitialise_server(void) */ size_t marshal_server_size(void) { - size_t rc = 5 * sizeof(int) + sizeof(uint32_t); + size_t rc = 6 * sizeof(int) + sizeof(uint32_t); rc += sizeof(struct stat); rc += PATH_MAX * sizeof(char); rc += mds_message_marshal_size(&received); @@ -304,6 +345,7 @@ int marshal_server(char* state_buf) buf_set_next(state_buf, int, display_tty_fd); buf_set_next(state_buf, int, vt_is_active); buf_set_next(state_buf, struct stat, old_vt_stat); + buf_set_next(state_buf, int, secondary_socket_fd); memcpy(state_buf, vtfile_path, PATH_MAX * sizeof(char)); state_buf += PATH_MAX; mds_message_marshal(&received, state_buf); @@ -334,6 +376,7 @@ int unmarshal_server(char* state_buf) buf_get_next(state_buf, int, display_tty_fd); buf_get_next(state_buf, int, vt_is_active); buf_get_next(state_buf, struct stat, old_vt_stat); + buf_set_next(state_buf, int, secondary_socket_fd); memcpy(vtfile_path, state_buf, PATH_MAX * sizeof(char)); state_buf += PATH_MAX; r = mds_message_unmarshal(&received, state_buf); @@ -391,7 +434,7 @@ int master_loop(void) else if (errno != ECONNRESET) goto pfail; - eprint("lost connection to server."); + eprint("lost primary connection to server."); mds_message_destroy(&received); mds_message_initialise(&received); connected = 0; @@ -410,13 +453,69 @@ int master_loop(void) pfail: xperror(*argv); fail: + rc |= secondary_thread_failed; if (rc || !reexecing) mds_message_destroy(&received); + if ((errno = pthread_join(secondary_thread, NULL))) + xperror(*argv); return rc; } /** + * Wait for confirmation that we may switch virtual terminal + * + * @param data Thread input parameter, will always be `NULL` + * @return Thread return value, will always be `NULL` + */ +void* secondary_loop(void* data) +{ + mds_message_t secondary_received; + int r; + (void) data; + + secondary_thread_started = 1; + fail_if (mds_message_initialise(&secondary_received) < 0); + + while (!reexecing && !terminating) + { + if (r = mds_message_read(&secondary_received, secondary_socket_fd), r == 0) + r = vt_accept_switch(display_tty_fd); + if (r == 0) + continue; + + if (r == -2) + { + eprint("corrupt message received, aborting."); + goto fail; + } + else if (errno == EINTR) + continue; + else if (errno != ECONNRESET) + goto pfail; + + eprint("lost secondary connection to server."); + mds_message_destroy(&secondary_received); + mds_message_initialise(&secondary_received); + if (reconnect_fd_to_display(&secondary_socket_fd) < 0) + goto fail; + } + + goto done; + pfail: + xperror(*argv); + fail: + secondary_thread_failed = 1; + done: + secondary_thread_started = 0; + mds_message_destroy(&secondary_received); + if (!reexecing && !terminating) + pthread_kill(master_thread, SIGTERM); + return NULL; +} + + +/** * Perform a VT switch requested by the OS kernel * * @param leave_foreground Whether the display is leaving the foreground @@ -436,7 +535,7 @@ int switch_vt(int leave_foreground) message_id = message_id == UINT32_MAX ? 0 : (message_id + 1); - return -!!full_send(buf, strlen(buf)); + return -!!full_send(socket_fd, buf, strlen(buf)); } @@ -535,7 +634,7 @@ int handle_get_vt(const char* client, const char* message) message_id = message_id == UINT32_MAX ? 0 : (message_id + 1); - r = full_send(buf, strlen(buf)); + r = full_send(socket_fd, buf, strlen(buf)); return ((active < 0) || r) ? -1 : 0; } @@ -571,7 +670,23 @@ int handle_configure_vt(const char* client, const char* message, const char* gra message_id = message_id == UINT32_MAX ? 0 : (message_id + 1); - return -!!full_send(buf, strlen(buf)); + return -!!full_send(socket_fd, buf, strlen(buf)); +} + + +/** + * Send a singal to all threads except the current thread + * + * @param signo The signal + */ +void signal_all(int signo) +{ + pthread_t current_thread = pthread_self(); + + if (pthread_equal(current_thread, master_thread) == 0) + pthread_kill(master_thread, signo); + else if (secondary_thread_started) + pthread_kill(secondary_thread, signo); } @@ -591,17 +706,18 @@ void received_switch_vt(int signo) /** * Send a full message even if interrupted * + * @param socket The file descriptor for the socket to use * @param message The message to send * @param length The length of the message - * @return Non-zero on success + * @return Zero on success, -1 on error */ -int full_send(const char* message, size_t length) +int full_send(int socket, const char* message, size_t length) { size_t sent; while (length > 0) { - sent = send_message(socket_fd, message, length); + sent = send_message(socket, message, length); if (sent > length) { eprint("Sent more of a message than exists in the message, aborting."); diff --git a/src/mds-vt.h b/src/mds-vt.h index 93e05de..48683dc 100644 --- a/src/mds-vt.h +++ b/src/mds-vt.h @@ -27,6 +27,15 @@ /** + * Wait for confirmation that we may switch virtual terminal + * + * @param data Thread input parameter, will always be `NULL` + * @return Thread return value, will always be `NULL` + */ +void* secondary_loop(void* data); + + +/** * Perform a VT switch requested by the OS kernel * * @param leave_foreground Whether the display is leaving the foreground @@ -75,11 +84,12 @@ void received_switch_vt(int signo); /** * Send a full message even if interrupted * + * @param socket The file descriptor for the socket to use * @param message The message to send * @param length The length of the message - * @return Non-zero on success + * @return Zero on success, -1 on error */ -int full_send(const char* message, size_t length); +int full_send(int socket, const char* message, size_t length); /** |