tel/tel.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <errno.h>
#include <sys/poll.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <signal.h>
#include <netdb.h>
#include <fcntl.h>
#include "libtel.h"

void handle_call(int sock) {
	fcntl(0, F_SETFL, O_NONBLOCK); 
	fcntl(sock, F_SETFL, O_NONBLOCK); 
	struct pollfd fds[2];
	fds[0].fd = 0;
	fds[0].events = POLLIN | POLLERR | POLLHUP;
	fds[1].fd = sock;
	fds[1].events = POLLIN | POLLERR | POLLHUP;

	while(1) {
		char buf[1024];
		int res = poll(fds, 2, -1);
		if(res < 0) {
			perror("error polling");
			goto end_err;
		}

		if(fds[0].revents & POLLIN) {
			while((res = read(0, buf, 1024)) > 0) {
				res = tel_write_all(sock, buf, res);
				if(res < 0) {
					perror("failed to send message");
					goto end_err;
				}
			}
			if(res < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
				perror("failed to read input");
				goto end_err;
			}
		} 
		if(fds[1].revents & POLLIN) {
			int readcount = 0;
			while((res = read(sock, buf, 1024)) > 0) {
				printf("%.*s", res, buf);
				readcount++;
			}
			if(res < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
				perror("failed to receive message");
				goto end_err;
			}
			if(readcount == 0) {
				printf("peer terminated call\n");
				goto end;
			}
		}
	}
end:
	close(sock);
	exit(0);
end_err:
	close(sock);
	exit(1);
}

int connect_local_sock(char *path) {
	int res;
	int sock;
	struct sockaddr_un addr;

	memset(&addr, 0, sizeof(struct sockaddr_un));
	addr.sun_family = AF_UNIX;
	strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);

	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if(sock < 0) {
		perror("error opening local socket");
		exit(1);
	}

	res = connect(sock, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
	if(res < 0) {
		perror("error connecting to local socket");
		exit(1);
	}

	return sock;
}

void pickup(struct sockaddr *addr) {
	int res;
	int sock = connect_local_sock("/tmp/tel.sock");

	res = tel_write_u32(sock, MSG_PICKUP);
	if(res < 0) goto write_err;

	res = tel_write_sockaddr(sock, addr);
	if(res < 0) goto write_err;

	uint32_t rsp;
	res = tel_read_u32(sock, &rsp);
	if(res < 0) goto read_err;

	switch(rsp) {
		case MSG_NONE:
			printf("no incoming calls from specified address\n");
			close(sock);
			return;
		case MSG_ERROR: {
			uint32_t len;
			res = tel_read_u32(sock, &len);
			if(res < 0) goto read_err;
			char buf[len + 1];
			res = tel_read_all(sock, buf, len);
			if(res < 0) goto read_err;
			buf[len] = '\0';
			fprintf(stderr, "error in daemon: %s\n", buf);
			close(sock);
			return;
		}
		case MSG_SOCKET: {
			int fd;
			int res = tel_read_fd(sock, &fd);
			if(res < 0) {
				perror("failed to receive fd");
				return;
			} else if(res == 0) {
				fprintf(stderr, "failed to receive fd: no data\n");
				return;
			}
			close(sock);
			printf("picked up call\n");
			handle_call(fd);
			return;
		}
		default:
			close(sock);
			return;
	}

read_err:
	perror("error reading socket");
	goto end;
write_err:
	perror("error writing socket");
	goto end;
end:
	close(sock);
}

void call(struct sockaddr *addr) {
	int res;
	int sock = connect_local_sock("/tmp/tel.sock");

	res = tel_write_u32(sock, MSG_CALL);
	if(res < 0) goto write_err;

	res = tel_write_sockaddr(sock, addr);
	if(res < 0) goto write_err;

	uint32_t rsp;
	res = tel_read_u32(sock, &rsp);
	if(res < 0) goto read_err;

	switch(rsp) {
		case MSG_NONE:
			printf("none\n");
			close(sock);
			return;
		case MSG_ERROR: {
			uint32_t len;
			res = tel_read_u32(sock, &len);
			if(res < 0) goto read_err;
			char buf[len + 1];
			res = tel_read_all(sock, buf, len);
			if(res < 0) goto read_err;
			buf[len] = '\0';
			fprintf(stderr, "error in daemon: %s\n", buf);
			close(sock);
			return;
		}
		case MSG_SOCKET: {
			int fd;
			int res = tel_read_fd(sock, &fd);
			if(res < 0) {
				perror("failed to receive fd");
				return;
			} else if(res == 0) {
				fprintf(stderr, "failed to receive fd: no data\n");
				return;
			}
			close(sock);
			printf("calling...\n");
			handle_call(fd);
			return;
		}
		default:
			close(sock);
			return;
	}

read_err:
	perror("error reading socket");
	goto end;
write_err:
	perror("error writing socket");
	goto end;
end:
	close(sock);
}

void usage_exit(char *name) {
	fprintf(stderr, "usage: %s call <addr> [ip] OR %s pkup <addr> [ip]", name, name);
	exit(1);
}

int main(int argc, char **argv) {
	if(argc < 1) exit(1);
	if(argc < 2) usage_exit(argv[0]);

	if(strcmp(argv[1], "call") == 0) {
		if(argc < 3 || argc > 4) usage_exit(argv[0]);

		struct sockaddr *addr;
		socklen_t addr_len;
		int res = tel_get_addr(argv[2], (argc < 4) ? NULL : argv[3], &addr, &addr_len);
		if(res != 0) {
			fprintf(stderr, "error: %s\n", gai_strerror(res));
			exit(1);
		}

		call(addr);

	} else if(strcmp(argv[1], "pkup") == 0) {
		if(argc < 3 || argc > 4) usage_exit(argv[0]);

		struct sockaddr *addr;
		socklen_t addr_len;
		int res = tel_get_addr(argv[2], (argc < 4) ? NULL : argv[3], &addr, &addr_len);
		if(res != 0) {
			fprintf(stderr, "error: %s\n", gai_strerror(res));
			exit(1);
		}

		pickup(addr);
	} else {
		usage_exit(argv[0]);
	}
}