diff options
Diffstat (limited to 'home/.bin/dtch.c')
| -rwxr-xr-x | home/.bin/dtch.c | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/home/.bin/dtch.c b/home/.bin/dtch.c deleted file mode 100755 index a37eeeeb..00000000 --- a/home/.bin/dtch.c +++ /dev/null @@ -1,254 +0,0 @@ -#if 0 -set -e -bin=$(dirname $0) -cc -Wall -Wextra -pedantic $@ -lutil -o $bin/dtch $0 -ln -f $bin/dtch $bin/atch -exit -#endif - -// Session attach and detach. - -#include <err.h> -#include <errno.h> -#include <fcntl.h> -#include <poll.h> -#include <pwd.h> -#include <stdio.h> -#include <stdlib.h> -#include <sys/ioctl.h> -#include <sys/socket.h> -#include <sys/stat.h> -#include <sys/types.h> -#include <sys/un.h> -#include <sys/wait.h> -#include <sysexits.h> -#include <termios.h> -#include <unistd.h> - -#if defined __FreeBSD__ -#include <libutil.h> -#elif defined __linux__ -#include <pty.h> -#else -#include <util.h> -#endif - -static struct passwd *getUser(void) { - uid_t uid = getuid(); - struct passwd *user = getpwuid(uid); - if (!user) err(EX_OSFILE, "/etc/passwd"); - return user; -} - -static struct sockaddr_un sockAddr(const char *home, const char *name) { - struct sockaddr_un addr = { .sun_family = AF_LOCAL }; - snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/.dtch/%s", home, name); - return addr; -} - -static ssize_t writeAll(int fd, const char *buf, size_t len) { - ssize_t writeLen; - while (0 < (writeLen = write(fd, buf, len))) { - buf += writeLen; - len -= writeLen; - } - return writeLen; -} - -char z; -struct iovec iov = { .iov_base = &z, .iov_len = 1 }; - -static ssize_t sendFd(int sock, int fd) { - size_t len = CMSG_LEN(sizeof(int)); - char buf[len]; - struct msghdr msg = { - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = buf, - .msg_controllen = len, - }; - - struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); - cmsg->cmsg_len = len; - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - *(int *)CMSG_DATA(cmsg) = fd; - - return sendmsg(sock, &msg, 0); -} - -static int recvFd(int sock) { - size_t len = CMSG_LEN(sizeof(int)); - char buf[len]; - struct msghdr msg = { - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = buf, - .msg_controllen = len, - }; - - ssize_t n = recvmsg(sock, &msg, 0); - if (n < 0) return -1; - - struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); - if (!cmsg) { errno = ENOMSG; return -1; } - if (cmsg->cmsg_type != SCM_RIGHTS) { errno = EBADMSG; return -1; } - - return *(int *)CMSG_DATA(cmsg); -} - -static struct sockaddr_un addr; - -static void unlinkAddr(void) { - unlink(addr.sun_path); -} - -static int dtch(int argc, char *argv[]) { - int error; - - struct passwd *user = getUser(); - - char *name = user->pw_name; - char *cmd = user->pw_shell; - if (argc > 2) { - name = argv[1]; - cmd = argv[2]; - argv += 2; - } else if (argc > 1) { - name = argv[1]; - argv++; - } - - int home = open(user->pw_dir, 0); - if (home < 0) err(EX_IOERR, "%s", user->pw_dir); - error = mkdirat(home, ".dtch", S_IRWXU); - if (error && errno != EEXIST) err(EX_IOERR, "%s/.dtch", user->pw_dir); - error = close(home); - if (error) err(EX_IOERR, "%s", user->pw_dir); - - int server = socket(PF_LOCAL, SOCK_STREAM, 0); - if (server < 0) err(EX_OSERR, "socket"); - - addr = sockAddr(user->pw_dir, name); - error = bind(server, (struct sockaddr *)&addr, sizeof(addr)); - if (error) err(EX_IOERR, "%s", addr.sun_path); - atexit(unlinkAddr); - - error = chmod(addr.sun_path, 0600); - if (error) err(EX_IOERR, "%s", addr.sun_path); - - int master; - pid_t pid = forkpty(&master, NULL, NULL, NULL); - if (pid < 0) err(EX_OSERR, "forkpty"); - - if (!pid) { - error = close(server); - if (error) warn("close(%d)", server); - execvp(cmd, argv); - err(EX_OSERR, "%s", cmd); - } - - error = listen(server, 0); - if (error) err(EX_OSERR, "listen"); - - for (;;) { - int client = accept(server, NULL, NULL); - if (client < 0) err(EX_IOERR, "accept(%d)", server); - - ssize_t len = sendFd(client, master); - if (len < 0) warn("sendmsg(%d)", client); - - len = recv(client, &z, sizeof(z), 0); - if (len < 0) warn("recv(%d)", client); - - error = close(client); - if (error) warn("close(%d)", client); - - pid_t dead = waitpid(pid, NULL, WNOHANG); - if (dead < 0) warn("waitpid(%d)", pid); - if (dead) exit(EX_OK); - } -} - -static struct termios saveTerm; - -static void restoreTerm(void) { - tcsetattr(STDERR_FILENO, TCSADRAIN, &saveTerm); - printf( - "\x1b[?1049l" // rmcup - "\x1b\x63\x1b[!p\x1b[?3;4l\x1b[4l\x1b>" // reset - ); -} - -static int atch(int argc, char *argv[]) { - int error; - - struct passwd *user = getUser(); - char *name = (argc > 1) ? argv[1] : user->pw_name; - - int client = socket(PF_LOCAL, SOCK_STREAM, 0); - if (client < 0) err(EX_OSERR, "socket"); - - struct sockaddr_un addr = sockAddr(user->pw_dir, name); - error = connect(client, (struct sockaddr *)&addr, sizeof(addr)); - if (error) err(EX_IOERR, "%s", addr.sun_path); - - int master = recvFd(client); - if (master < 0) err(EX_IOERR, "recvmsg(%d)", client); - - struct winsize window; - error = ioctl(STDERR_FILENO, TIOCGWINSZ, &window); - if (error) err(EX_IOERR, "ioctl(%d, TIOCGWINSZ)", STDERR_FILENO); - - error = ioctl(master, TIOCSWINSZ, &window); - if (error) err(EX_IOERR, "ioctl(%d, TIOCSWINSZ)", master); - - error = tcgetattr(STDERR_FILENO, &saveTerm); - if (error) err(EX_IOERR, "tcgetattr(%d)", STDERR_FILENO); - atexit(restoreTerm); - - struct termios raw; - cfmakeraw(&raw); - error = tcsetattr(STDERR_FILENO, TCSADRAIN, &raw); - if (error) err(EX_IOERR, "tcsetattr(%d)", STDERR_FILENO); - - char ctrlL = CTRL('L'); - ssize_t len = write(master, &ctrlL, 1); - if (len < 0) err(EX_IOERR, "write(%d)", master); - - struct pollfd fds[2] = { - { .fd = STDIN_FILENO, .events = POLLIN }, - { .fd = master, .events = POLLIN }, - }; - - while (0 < poll(fds, 2, -1)) { - char buf[4096]; - ssize_t len; - - if (fds[0].revents) { - len = read(STDIN_FILENO, buf, sizeof(buf)); - if (len < 0) err(EX_IOERR, "read(%d)", STDIN_FILENO); - - if (len && buf[0] == CTRL('Q')) exit(EX_OK); - - len = writeAll(master, buf, len); - if (len < 0) err(EX_IOERR, "write(%d)", master); - } - - if (fds[1].revents) { - len = read(master, buf, sizeof(buf)); - if (len < 0) err(EX_IOERR, "read(%d)", master); - len = writeAll(STDOUT_FILENO, buf, len); - if (len < 0) err(EX_IOERR, "write(%d)", STDOUT_FILENO); - } - } - err(EX_IOERR, "poll([%d,%d])", STDIN_FILENO, master); -} - -int main(int argc, char *argv[]) { - switch (argv[0][0]) { - case 'd': return dtch(argc, argv); - case 'a': return atch(argc, argv); - } - return EX_USAGE; -} |