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-rw-r--r--src/cli/ipc.c555
1 files changed, 555 insertions, 0 deletions
diff --git a/src/cli/ipc.c b/src/cli/ipc.c
new file mode 100644
index 0000000..6d555c0
--- /dev/null
+++ b/src/cli/ipc.c
@@ -0,0 +1,555 @@
+#include "../../include/cli/ipc.h"
+#include "../../include/recorder/error.h"
+#include "../../include/recorder/replay_save.h"
+#include "../../include/log.h"
+
+#define SJ_IMPL
+#include "../../external/sj.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <poll.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+
+#define GSR_IPC_MAX_REQUEST_NAME_SIZE 64
+#define GSR_IPC_MAX_ESCAPED_ERROR_MESSAGE_SIZE (GSR_IPC_MAX_ERROR_MESSAGE_SIZE*6)
+#define GSR_IPC_MAX_REPLY_SIZE (GSR_IPC_MAX_ESCAPED_ERROR_MESSAGE_SIZE + 128)
+#define GSR_IPC_SEND_TIMEOUT_MILLISECONDS 1000
+#define GSR_IPC_SOCKET_MODE 0600
+
+typedef struct {
+ int64_t id;
+ char name[GSR_IPC_MAX_REQUEST_NAME_SIZE];
+ sj_Value data;
+ bool has_data;
+} gsr_ipc_request;
+
+static void json_escape_string(char *buffer, size_t buffer_size, const char *str) {
+ char escape_buffer[8];
+ size_t offset = 0;
+ buffer[0] = '\0';
+
+ for(size_t i = 0; str[i] != '\0'; ++i) {
+ const unsigned char c = str[i];
+ const char *escaped = escape_buffer;
+ switch(c) {
+ case '"': escaped = "\\\""; break;
+ case '\\': escaped = "\\\\"; break;
+ case '\n': escaped = "\\n"; break;
+ case '\r': escaped = "\\r"; break;
+ case '\t': escaped = "\\t"; break;
+ default: {
+ if(c < 0x20)
+ snprintf(escape_buffer, sizeof(escape_buffer), "\\u%04x", c);
+ else
+ snprintf(escape_buffer, sizeof(escape_buffer), "%c", c);
+ break;
+ }
+ }
+
+ const size_t escaped_size = strlen(escaped);
+ if(offset + escaped_size >= buffer_size)
+ break;
+
+ memcpy(buffer + offset, escaped, escaped_size);
+ offset += escaped_size;
+ buffer[offset] = '\0';
+ }
+}
+
+static bool json_string_equals(const sj_Value *value, const char *str) {
+ const size_t value_size = value->end - value->start;
+ return strlen(str) == value_size && memcmp(value->start, str, value_size) == 0;
+}
+
+static bool json_number_to_int64(const sj_Value *value, int64_t *result) {
+ char buffer[32];
+ const size_t value_size = value->end - value->start;
+ if(value_size == 0 || value_size >= sizeof(buffer))
+ return false;
+
+ memcpy(buffer, value->start, value_size);
+ buffer[value_size] = '\0';
+
+ char *number_end = NULL;
+ errno = 0;
+ const long long parsed_value = strtoll(buffer, &number_end, 10);
+ if(errno != 0 || number_end != buffer + value_size)
+ return false;
+
+ *result = parsed_value;
+ return true;
+}
+
+static bool string_is_only_whitespace(const char *str, size_t size) {
+ for(size_t i = 0; i < size; ++i) {
+ if(str[i] != ' ' && str[i] != '\t' && str[i] != '\r' && str[i] != '\n')
+ return false;
+ }
+ return true;
+}
+
+static bool ipc_send_all(int fd, const char *data, size_t size) {
+ size_t offset = 0;
+ while(offset < size) {
+ const ssize_t bytes_written = send(fd, data + offset, size - offset, MSG_NOSIGNAL);
+ if(bytes_written > 0) {
+ offset += bytes_written;
+ continue;
+ }
+
+ if(bytes_written == -1 && errno == EINTR)
+ continue;
+
+ if(bytes_written == -1 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
+ struct pollfd poll_fd;
+ poll_fd.fd = fd;
+ poll_fd.events = POLLOUT;
+ poll_fd.revents = 0;
+
+ const int poll_result = poll(&poll_fd, 1, GSR_IPC_SEND_TIMEOUT_MILLISECONDS);
+ if(poll_result == -1 && errno == EINTR)
+ continue;
+
+ if(poll_result <= 0)
+ return false;
+
+ continue;
+ }
+
+ return false;
+ }
+ return true;
+}
+
+static bool ipc_client_send_reply(gsr_ipc_client *client, int64_t id, bool success, const char *error_message) {
+ char reply[GSR_IPC_MAX_REPLY_SIZE];
+ int reply_size = 0;
+
+ if(success) {
+ reply_size = snprintf(reply, sizeof(reply), "{\"id\":%" PRIi64 ",\"result\":\"ok\"}\n", id);
+ } else {
+ char escaped_error_message[GSR_IPC_MAX_ESCAPED_ERROR_MESSAGE_SIZE];
+ json_escape_string(escaped_error_message, sizeof(escaped_error_message), error_message ? error_message : "");
+ reply_size = snprintf(reply, sizeof(reply), "{\"id\":%" PRIi64 ",\"result\":\"error\",\"data\":\"%s\"}\n", id, escaped_error_message);
+ }
+
+ if(reply_size < 0 || reply_size >= (int)sizeof(reply)) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc: failed to create a reply to request %" PRIi64, id);
+ return false;
+ }
+
+ return ipc_send_all(client->fd, reply, reply_size);
+}
+
+static bool ipc_request_parse(char *data, size_t size, gsr_ipc_request *request, char *error_message, size_t error_message_size) {
+ memset(request, 0, sizeof(*request));
+
+ sj_Reader reader = sj_reader(data, size);
+ const sj_Value root = sj_read(&reader);
+ if(root.type != SJ_OBJECT) {
+ snprintf(error_message, error_message_size, "expected the request to be a json object");
+ return false;
+ }
+
+ sj_Value id_value;
+ sj_Value name_value;
+ bool has_id = false;
+ bool has_name = false;
+
+ sj_Value key;
+ sj_Value value;
+ while(sj_iter_object(&reader, root, &key, &value)) {
+ if(json_string_equals(&key, "id")) {
+ id_value = value;
+ has_id = true;
+ } else if(json_string_equals(&key, "name")) {
+ name_value = value;
+ has_name = true;
+ } else if(json_string_equals(&key, "data")) {
+ request->data = value;
+ request->has_data = true;
+ }
+ }
+
+ if(reader.error) {
+ snprintf(error_message, error_message_size, "failed to parse the request: %s", reader.error);
+ return false;
+ }
+
+ if(!has_id) {
+ snprintf(error_message, error_message_size, "the request is missing the 'id' field");
+ return false;
+ }
+
+ if(id_value.type != SJ_NUMBER || !json_number_to_int64(&id_value, &request->id)) {
+ snprintf(error_message, error_message_size, "expected 'id' to be an integer");
+ return false;
+ }
+
+ if(!has_name) {
+ snprintf(error_message, error_message_size, "the request is missing the 'name' field");
+ return false;
+ }
+
+ if(name_value.type != SJ_STRING) {
+ snprintf(error_message, error_message_size, "expected 'name' to be a string");
+ return false;
+ }
+
+ snprintf(request->name, sizeof(request->name), "%.*s", (int)(name_value.end - name_value.start), name_value.start);
+ return true;
+}
+
+static bool ipc_request_get_save_replay_seconds(const gsr_ipc_request *request, int *seconds, char *error_message, size_t error_message_size) {
+ *seconds = GSR_SAVE_REPLAY_SECONDS_FULL;
+ if(!request->has_data || request->data.type == SJ_NULL)
+ return true;
+
+ int64_t data_seconds = 0;
+ if(request->data.type != SJ_NUMBER || !json_number_to_int64(&request->data, &data_seconds) || data_seconds <= 0 || data_seconds > INT_MAX) {
+ snprintf(error_message, error_message_size, "expected 'data' to be the number of seconds to save, which has to be larger than 0");
+ return false;
+ }
+
+ *seconds = data_seconds;
+ return true;
+}
+
+static bool ipc_handle_request(gsr_ipc *self, const gsr_ipc_request *request, char *error_message, size_t error_message_size) {
+ if(strcmp(request->name, "stop") == 0)
+ return self->handlers.stop(error_message, error_message_size, self->handlers.userdata);
+
+ if(strcmp(request->name, "toggle-pause") == 0)
+ return self->handlers.toggle_pause(error_message, error_message_size, self->handlers.userdata);
+
+ if(strcmp(request->name, "toggle-replay-recording") == 0)
+ return self->handlers.toggle_replay_recording(error_message, error_message_size, self->handlers.userdata);
+
+ if(strcmp(request->name, "save-replay") == 0) {
+ int seconds = GSR_SAVE_REPLAY_SECONDS_FULL;
+ if(!ipc_request_get_save_replay_seconds(request, &seconds, error_message, error_message_size))
+ return false;
+
+ return self->handlers.save_replay(seconds, error_message, error_message_size, self->handlers.userdata);
+ }
+
+ snprintf(error_message, error_message_size, "unknown request name '%s'", request->name);
+ return false;
+}
+
+static bool ipc_client_on_request(gsr_ipc *self, gsr_ipc_client *client) {
+ if(client->request_too_large)
+ return ipc_client_send_reply(client, 0, false, "the request is too large");
+
+ if(string_is_only_whitespace(client->request, client->request_size))
+ return ipc_client_send_reply(client, 0, false, "the request is empty");
+
+ char error_message[GSR_IPC_MAX_ERROR_MESSAGE_SIZE];
+ error_message[0] = '\0';
+
+ gsr_ipc_request request;
+ if(!ipc_request_parse(client->request, client->request_size, &request, error_message, sizeof(error_message)))
+ return ipc_client_send_reply(client, request.id, false, error_message);
+
+ if(!ipc_handle_request(self, &request, error_message, sizeof(error_message)))
+ return ipc_client_send_reply(client, request.id, false, error_message);
+
+ return ipc_client_send_reply(client, request.id, true, NULL);
+}
+
+static bool ipc_client_on_byte(gsr_ipc *self, gsr_ipc_client *client, char c) {
+ if(c != '\n') {
+ if(client->request_size < GSR_IPC_MAX_REQUEST_SIZE)
+ client->request[client->request_size++] = c;
+ else
+ client->request_too_large = true;
+ return true;
+ }
+
+ const bool keep_client = ipc_client_on_request(self, client);
+ client->request_size = 0;
+ client->request_too_large = false;
+ return keep_client;
+}
+
+static bool ipc_client_receive(gsr_ipc *self, gsr_ipc_client *client) {
+ for(;;) {
+ char buffer[1024];
+ const ssize_t bytes_read = recv(client->fd, buffer, sizeof(buffer), 0);
+ if(bytes_read == 0)
+ return false;
+
+ if(bytes_read == -1) {
+ if(errno == EINTR)
+ continue;
+
+ return errno == EAGAIN || errno == EWOULDBLOCK;
+ }
+
+ for(ssize_t i = 0; i < bytes_read; ++i) {
+ if(!ipc_client_on_byte(self, client, buffer[i]))
+ return false;
+ }
+ }
+}
+
+static bool fd_set_cloexec(int fd) {
+ const int flags = fcntl(fd, F_GETFD);
+ return flags != -1 && fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1;
+}
+
+static bool fd_set_nonblocking(int fd) {
+ const int flags = fcntl(fd, F_GETFL);
+ return flags != -1 && fcntl(fd, F_SETFL, flags | O_NONBLOCK) != -1;
+}
+
+static void ipc_add_client(gsr_ipc *self, int client_fd) {
+ if(self->num_clients == GSR_IPC_MAX_CLIENTS) {
+ gsr_log(GSR_LOG_LEVEL_WARNING, "gsr_ipc: too many ipc clients are connected, rejecting the new connection");
+ close(client_fd);
+ return;
+ }
+
+ if(!fd_set_cloexec(client_fd) || !fd_set_nonblocking(client_fd)) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc: failed to setup the ipc client socket, error: %s", strerror(errno));
+ close(client_fd);
+ return;
+ }
+
+ gsr_ipc_client *client = &self->clients[self->num_clients];
+ client->fd = client_fd;
+ client->request_size = 0;
+ client->request_too_large = false;
+ ++self->num_clients;
+}
+
+static void ipc_accept_client(gsr_ipc *self) {
+ const int client_fd = accept(self->socket_fd, NULL, NULL);
+ if(client_fd == -1)
+ return;
+
+ ipc_add_client(self, client_fd);
+}
+
+static void ipc_remove_client(gsr_ipc *self, int index) {
+ close(self->clients[index].fd);
+ for(int i = index; i < self->num_clients - 1; ++i) {
+ self->clients[i] = self->clients[i + 1];
+ }
+ --self->num_clients;
+}
+
+static void* ipc_thread(void *userdata) {
+ gsr_ipc *self = userdata;
+ struct pollfd poll_fds[2 + GSR_IPC_MAX_CLIENTS];
+
+ for(;;) {
+ poll_fds[0].fd = self->wakeup_pipe[0];
+ poll_fds[0].events = POLLIN;
+ poll_fds[0].revents = 0;
+ poll_fds[1].fd = self->socket_fd;
+ poll_fds[1].events = POLLIN;
+ poll_fds[1].revents = 0;
+
+ const int num_polled_clients = self->num_clients;
+ for(int i = 0; i < num_polled_clients; ++i) {
+ poll_fds[2 + i].fd = self->clients[i].fd;
+ poll_fds[2 + i].events = POLLIN;
+ poll_fds[2 + i].revents = 0;
+ }
+
+ if(poll(poll_fds, 2 + num_polled_clients, -1) == -1) {
+ if(errno == EINTR)
+ continue;
+
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc: failed to poll the ipc sockets, error: %s", strerror(errno));
+ break;
+ }
+
+ if(poll_fds[0].revents != 0)
+ break;
+
+ if(poll_fds[1].revents & POLLIN)
+ ipc_accept_client(self);
+
+ for(int i = num_polled_clients - 1; i >= 0; --i) {
+ bool keep_client = true;
+ if(poll_fds[2 + i].revents & POLLIN)
+ keep_client = ipc_client_receive(self, &self->clients[i]);
+ else if(poll_fds[2 + i].revents & (POLLHUP | POLLERR | POLLNVAL))
+ keep_client = false;
+
+ if(!keep_client)
+ ipc_remove_client(self, i);
+ }
+ }
+
+ return NULL;
+}
+
+static bool ipc_socket_filepath_in_use(const char *socket_filepath) {
+ struct sockaddr_un addr;
+ memset(&addr, 0, sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", socket_filepath);
+
+ const int fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
+ if(fd == -1)
+ return true;
+
+ const bool in_use = connect(fd, (const struct sockaddr*)&addr, sizeof(addr)) == 0;
+ close(fd);
+ return in_use;
+}
+
+static bool ipc_bind(gsr_ipc *self, const struct sockaddr_un *addr) {
+ const mode_t prev_mask = umask(0777 & ~GSR_IPC_SOCKET_MODE);
+ int bind_result = bind(self->socket_fd, (const struct sockaddr*)addr, sizeof(*addr));
+ if(bind_result == -1 && errno == EADDRINUSE && !ipc_socket_filepath_in_use(self->socket_filepath)) {
+ unlink(self->socket_filepath);
+ bind_result = bind(self->socket_fd, (const struct sockaddr*)addr, sizeof(*addr));
+ }
+ const int bind_error = errno;
+ umask(prev_mask);
+
+ if(bind_result == -1) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: failed to bind the ipc socket to \"%s\", error: %s", self->socket_filepath, strerror(bind_error));
+ return false;
+ }
+
+ self->socket_bound = true;
+ return true;
+}
+
+static void ipc_close(gsr_ipc *self) {
+ for(int i = 0; i < self->num_clients; ++i) {
+ close(self->clients[i].fd);
+ }
+ self->num_clients = 0;
+
+ for(int i = 0; i < 2; ++i) {
+ if(self->wakeup_pipe[i] != -1) {
+ close(self->wakeup_pipe[i]);
+ self->wakeup_pipe[i] = -1;
+ }
+ }
+
+ if(self->socket_fd != -1) {
+ close(self->socket_fd);
+ self->socket_fd = -1;
+ }
+
+ if(self->socket_bound) {
+ unlink(self->socket_filepath);
+ self->socket_bound = false;
+ }
+}
+
+int gsr_ipc_init(gsr_ipc *self, const char *socket_filepath) {
+ memset(self, 0, sizeof(*self));
+ self->socket_fd = -1;
+ self->wakeup_pipe[0] = -1;
+ self->wakeup_pipe[1] = -1;
+
+ struct sockaddr_un addr;
+ memset(&addr, 0, sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ if(snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", socket_filepath) >= (int)sizeof(addr.sun_path)) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: the ipc socket path is too long, it can be at most %d characters: \"%s\"", (int)sizeof(addr.sun_path) - 1, socket_filepath);
+ goto err;
+ }
+
+ snprintf(self->socket_filepath, sizeof(self->socket_filepath), "%s", socket_filepath);
+
+ if(pipe(self->wakeup_pipe) == -1) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: failed to create the ipc wakeup pipe, error: %s", strerror(errno));
+ self->wakeup_pipe[0] = -1;
+ self->wakeup_pipe[1] = -1;
+ goto err;
+ }
+
+ if(!fd_set_cloexec(self->wakeup_pipe[0]) || !fd_set_cloexec(self->wakeup_pipe[1])) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: failed to setup the ipc wakeup pipe, error: %s", strerror(errno));
+ goto err;
+ }
+
+ self->socket_fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
+ if(self->socket_fd == -1) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: failed to create the ipc socket, error: %s", strerror(errno));
+ goto err;
+ }
+
+ if(!ipc_bind(self, &addr))
+ goto err;
+
+ if(listen(self->socket_fd, GSR_IPC_MAX_CLIENTS) == -1) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_init: failed to listen on the ipc socket, error: %s", strerror(errno));
+ goto err;
+ }
+
+ self->initialized = true;
+ return GSR_ERROR_OK;
+
+ err:
+ ipc_close(self);
+ return GSR_ERROR_GENERIC;
+}
+
+void gsr_ipc_deinit(gsr_ipc *self) {
+ if(!self->initialized)
+ return;
+
+ gsr_ipc_stop(self);
+ ipc_close(self);
+ self->initialized = false;
+}
+
+int gsr_ipc_start(gsr_ipc *self, const gsr_ipc_handlers *handlers) {
+ if(!self->initialized)
+ return GSR_ERROR_OK;
+
+ self->handlers = *handlers;
+
+ /* Block all signals in the ipc thread to keep the signal handlers running on the main thread */
+ sigset_t all_signals;
+ sigset_t prev_signals;
+ sigfillset(&all_signals);
+ pthread_sigmask(SIG_SETMASK, &all_signals, &prev_signals);
+ const int thread_create_result = pthread_create(&self->thread, NULL, ipc_thread, self);
+ pthread_sigmask(SIG_SETMASK, &prev_signals, NULL);
+
+ if(thread_create_result != 0) {
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_start: failed to create the ipc thread, error: %s", strerror(thread_create_result));
+ return GSR_ERROR_GENERIC;
+ }
+
+ self->thread_running = true;
+ return GSR_ERROR_OK;
+}
+
+void gsr_ipc_stop(gsr_ipc *self) {
+ if(!self->thread_running)
+ return;
+
+ const char wakeup_value = 1;
+ ssize_t bytes_written = 0;
+ do {
+ bytes_written = write(self->wakeup_pipe[1], &wakeup_value, 1);
+ } while(bytes_written == -1 && errno == EINTR);
+
+ if(bytes_written == -1)
+ gsr_log(GSR_LOG_LEVEL_ERROR, "gsr_ipc_stop: failed to wake up the ipc thread, error: %s", strerror(errno));
+
+ pthread_join(self->thread, NULL);
+ self->thread_running = false;
+}
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