X-Git-Url: https://git.distorted.org.uk/~mdw/termux-packages/blobdiff_plain/27ce01e83bf0264b9aed9595226ef84f07ca0f52..382cfb780ca9a40f80e3932544bd32aeccb66e5a:/packages/termux-api/termux-api.c diff --git a/packages/termux-api/termux-api.c b/packages/termux-api/termux-api.c index f1eaa711..27e4ae70 100644 --- a/packages/termux-api/termux-api.c +++ b/packages/termux-api/termux-api.c @@ -24,151 +24,132 @@ #include // Function which execs "am broadcast ..". -void exec_am_broadcast(int argc, char** argv, char* input_address_string, char* output_address_string) +_Noreturn void exec_am_broadcast(int argc, char** argv, char* input_address_string, char* output_address_string) { - // Redirect stdout to /dev/null (but leave stderr open): - close(STDOUT_FILENO); - open("/dev/null", O_RDONLY); - // Close stdin: - close(STDIN_FILENO); - - char const* const file = "/system/bin/am"; - // Avoid the system am binary from linking to wrong libraries: - unsetenv("LD_LIBRARY_PATH"); - // Ensure /system/bin/app_process is in path, which is needed by am in some systems: - putenv("PATH=/system/bin"); - - // The user is calculated from the uid in android.os.UserHandle#getUserId(int uid) as "uid / 100000", so we do the same: - uid_t current_uid = getuid(); - int android_user_id = current_uid / 100000; - char* android_user_id_string; - if (asprintf(&android_user_id_string, "%d", android_user_id) == -1) { - fprintf(stderr, "asprintf() error"); - return; - } - - int const extra_args = 15; // Including ending NULL. - char** child_argv = malloc((sizeof(char*)) * (argc + extra_args)); - - child_argv[0] = "am"; - child_argv[1] = "broadcast"; - child_argv[2] = "--user"; - child_argv[3] = android_user_id_string; - child_argv[4] = "-n"; - child_argv[5] = "com.termux.api/.TermuxApiReceiver"; - child_argv[6] = "--es"; - // Input/output are reversed for the java process (our output is its input): - child_argv[7] = "socket_input"; - child_argv[8] = output_address_string; - child_argv[9] = "--es"; - child_argv[10] = "socket_output"; - child_argv[11] = input_address_string; - child_argv[12] = "--es"; - child_argv[13] = "api_method"; - child_argv[14] = argv[1]; - - // Copy the remaining arguments -2 for first binary and second api name: - memcpy(child_argv + extra_args, argv + 2, (argc-1) * sizeof(char*)); - - // End with NULL: - child_argv[argc + extra_args] = NULL; - - execv(file, child_argv); - perror("execv(\"/system/bin/am\")"); - exit(1); + // Redirect stdout to /dev/null (but leave stderr open): + close(STDOUT_FILENO); + open("/dev/null", O_RDONLY); + // Close stdin: + close(STDIN_FILENO); + + int const extra_args = 15; // Including ending NULL. + char** child_argv = malloc((sizeof(char*)) * (argc + extra_args)); + + child_argv[0] = "am"; + child_argv[1] = "broadcast"; + child_argv[2] = "--user"; + child_argv[3] = "0"; + child_argv[4] = "-n"; + child_argv[5] = "com.termux.api/.TermuxApiReceiver"; + child_argv[6] = "--es"; + // Input/output are reversed for the java process (our output is its input): + child_argv[7] = "socket_input"; + child_argv[8] = output_address_string; + child_argv[9] = "--es"; + child_argv[10] = "socket_output"; + child_argv[11] = input_address_string; + child_argv[12] = "--es"; + child_argv[13] = "api_method"; + child_argv[14] = argv[1]; + + // Copy the remaining arguments -2 for first binary and second api name: + memcpy(child_argv + extra_args, argv + 2, (argc-1) * sizeof(char*)); + + // End with NULL: + child_argv[argc + extra_args] = NULL; + + // Use an a executable taking care of PATH and LD_LIBRARY_PATH: + execv("/data/data/com.termux/files/usr/bin/am", child_argv); + + perror("execv(\"/data/data/com.termux/files/usr/bin/am\")"); + exit(1); } void generate_uuid(char* str) { - sprintf(str, "%x%x-%x-%x-%x-%x%x%x", - rand(), rand(), // Generates a 64-bit Hex number - (uint32_t) getpid(), // Generates a 32-bit Hex number - ((rand() & 0x0fff) | 0x4000), // Generates a 32-bit Hex number of the form 4xxx (4 indicates the UUID version) - rand() % 0x3fff + 0x8000, // Generates a 32-bit Hex number in the range [0x8000, 0xbfff] - rand(), rand(), rand()); // Generates a 96-bit Hex number + sprintf(str, "%x%x-%x-%x-%x-%x%x%x", + arc4random(), arc4random(), // Generates a 64-bit Hex number + (uint32_t) getpid(), // Generates a 32-bit Hex number + ((arc4random() & 0x0fff) | 0x4000), // Generates a 32-bit Hex number of the form 4xxx (4 indicates the UUID version) + arc4random() % 0x3fff + 0x8000, // Generates a 32-bit Hex number in the range [0x8000, 0xbfff] + arc4random(), arc4random(), arc4random()); // Generates a 96-bit Hex number } // Thread function which reads from stdin and writes to socket. void* transmit_stdin_to_socket(void* arg) { - int output_server_socket = *((int*) arg); - struct sockaddr_un remote_addr; - socklen_t addrlen = sizeof(remote_addr); - int output_client_socket = accept(output_server_socket, (struct sockaddr*) &remote_addr, &addrlen); - - int len; - char buffer[1024]; - while (len = read(STDIN_FILENO, &buffer, sizeof(buffer)-1), len > 0) { - if (write(output_client_socket, buffer, len) < 0) break; - } - // Close output socket on end of input: - close(output_client_socket); - return NULL; + int output_server_socket = *((int*) arg); + struct sockaddr_un remote_addr; + socklen_t addrlen = sizeof(remote_addr); + int output_client_socket = accept(output_server_socket, (struct sockaddr*) &remote_addr, &addrlen); + + ssize_t len; + char buffer[1024]; + while (len = read(STDIN_FILENO, &buffer, sizeof(buffer)), len > 0) { + if (write(output_client_socket, buffer, len) < 0) break; + } + // Close output socket on end of input: + close(output_client_socket); + return NULL; } // Main thread function which reads from input socket and writes to stdout. void transmit_socket_to_stdout(int input_socket_fd) { - int len; - char buffer[1024]; - while ((len = read(input_socket_fd, &buffer, sizeof(buffer)-1)) > 0) { - buffer[len] = 0; - write(STDOUT_FILENO, buffer, len); - } - if (len < 0) perror("read()"); + ssize_t len; + char buffer[1024]; + while ((len = read(input_socket_fd, &buffer, sizeof(buffer))) > 0) { + write(STDOUT_FILENO, buffer, len); + } + if (len < 0) perror("read()"); } int main(int argc, char** argv) { - // Do not transform children into zombies when they terminate: - struct sigaction sigchld_action = { .sa_handler = SIG_DFL, .sa_flags = SA_RESTART | SA_NOCLDSTOP | SA_NOCLDWAIT }; - sigaction(SIGCHLD, &sigchld_action, NULL); - - char input_address_string[100]; // This program reads from it. - char output_address_string[100]; // This program writes to it. - - // Seed the random number generator: - struct timeval time; - gettimeofday(&time,NULL); - srand((time.tv_sec * 1000) + (time.tv_usec / 1000)); - - generate_uuid(input_address_string); - generate_uuid(output_address_string); - - struct sockaddr_un input_address = { .sun_family = AF_UNIX }; - struct sockaddr_un output_address = { .sun_family = AF_UNIX }; - // Leave struct sockaddr_un.sun_path[0] as 0 and use the UUID string as abstract linux namespace: - strncpy(&input_address.sun_path[1], input_address_string, strlen(input_address_string)); - strncpy(&output_address.sun_path[1], output_address_string, strlen(output_address_string)); - - int input_server_socket = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); - if (input_server_socket == -1) { perror("socket()"); return 1; } - int output_server_socket = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); - if (output_server_socket == -1) { perror("socket()"); return 1; } - - if (bind(input_server_socket, (struct sockaddr*) &input_address, sizeof(sa_family_t) + strlen(input_address_string) + 1) == -1) { - perror("bind(input)"); - return 1; - } - if (bind(output_server_socket, (struct sockaddr*) &output_address, sizeof(sa_family_t) + strlen(output_address_string) + 1) == -1) { - perror("bind(output)"); - return 1; - } - - if (listen(input_server_socket, 1) == -1) { perror("listen()"); return 1; } - if (listen(output_server_socket, 1) == -1) { perror("listen()"); return 1; } - - pid_t fork_result = fork(); - switch (fork_result) { - case -1: perror("fork()"); return 1; - case 0: exec_am_broadcast(argc, argv, input_address_string, output_address_string); return 0; - } - - struct sockaddr_un remote_addr; - socklen_t addrlen = sizeof(remote_addr); - int input_client_socket = accept(input_server_socket, (struct sockaddr*) &remote_addr, &addrlen); - - pthread_t transmit_thread; - pthread_create(&transmit_thread, NULL, transmit_stdin_to_socket, &output_server_socket); - - transmit_socket_to_stdout(input_client_socket); - - return 0; + // Do not transform children into zombies when they terminate: + struct sigaction sigchld_action = { .sa_handler = SIG_DFL, .sa_flags = SA_RESTART | SA_NOCLDSTOP | SA_NOCLDWAIT }; + sigaction(SIGCHLD, &sigchld_action, NULL); + + char input_address_string[100]; // This program reads from it. + char output_address_string[100]; // This program writes to it. + + generate_uuid(input_address_string); + generate_uuid(output_address_string); + + struct sockaddr_un input_address = { .sun_family = AF_UNIX }; + struct sockaddr_un output_address = { .sun_family = AF_UNIX }; + // Leave struct sockaddr_un.sun_path[0] as 0 and use the UUID string as abstract linux namespace: + strncpy(&input_address.sun_path[1], input_address_string, strlen(input_address_string)); + strncpy(&output_address.sun_path[1], output_address_string, strlen(output_address_string)); + + int input_server_socket = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); + if (input_server_socket == -1) { perror("socket()"); return 1; } + int output_server_socket = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); + if (output_server_socket == -1) { perror("socket()"); return 1; } + + if (bind(input_server_socket, (struct sockaddr*) &input_address, sizeof(sa_family_t) + strlen(input_address_string) + 1) == -1) { + perror("bind(input)"); + return 1; + } + if (bind(output_server_socket, (struct sockaddr*) &output_address, sizeof(sa_family_t) + strlen(output_address_string) + 1) == -1) { + perror("bind(output)"); + return 1; + } + + if (listen(input_server_socket, 1) == -1) { perror("listen()"); return 1; } + if (listen(output_server_socket, 1) == -1) { perror("listen()"); return 1; } + + pid_t fork_result = fork(); + switch (fork_result) { + case -1: perror("fork()"); return 1; + case 0: exec_am_broadcast(argc, argv, input_address_string, output_address_string); + } + + struct sockaddr_un remote_addr; + socklen_t addrlen = sizeof(remote_addr); + int input_client_socket = accept(input_server_socket, (struct sockaddr*) &remote_addr, &addrlen); + + pthread_t transmit_thread; + pthread_create(&transmit_thread, NULL, transmit_stdin_to_socket, &output_server_socket); + + transmit_socket_to_stdout(input_client_socket); + + return 0; }