#include <unistd.h>
// 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;
}
~mdw / termux-packages / blobdiff