| 1 | /* |
| 2 | * Main program. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <stddef.h> |
| 8 | #include <stdarg.h> |
| 9 | #include <signal.h> |
| 10 | #include <string.h> |
| 11 | #include <errno.h> |
| 12 | |
| 13 | #include <unistd.h> |
| 14 | #include <sys/types.h> |
| 15 | #include <sys/wait.h> |
| 16 | |
| 17 | #include "sel.h" |
| 18 | #include "pty.h" |
| 19 | #include "telnet.h" |
| 20 | |
| 21 | int signalpipe[2]; |
| 22 | |
| 23 | sel *asel; |
| 24 | sel_rfd *netr, *ptyr, *sigr; |
| 25 | int ptyfd; |
| 26 | sel_wfd *netw, *ptyw; |
| 27 | Telnet telnet; |
| 28 | |
| 29 | #define BUF 65536 |
| 30 | |
| 31 | void sigchld(int signum) |
| 32 | { |
| 33 | write(signalpipe[1], "C", 1); |
| 34 | } |
| 35 | |
| 36 | void fatal(const char *fmt, ...) |
| 37 | { |
| 38 | va_list ap; |
| 39 | fprintf(stderr, "FIXME: "); |
| 40 | va_start(ap, fmt); |
| 41 | vfprintf(stderr, fmt, ap); |
| 42 | va_end(ap); |
| 43 | fprintf(stderr, "\n"); |
| 44 | exit(1); |
| 45 | } |
| 46 | |
| 47 | void net_readdata(sel_rfd *rfd, void *data, size_t len) |
| 48 | { |
| 49 | if (len == 0) |
| 50 | exit(0); /* EOF on network - client went away */ |
| 51 | telnet_from_net(telnet, data, len); |
| 52 | if (sel_write(netw, NULL, 0) > BUF) |
| 53 | sel_rfd_freeze(ptyr); |
| 54 | if (sel_write(ptyw, NULL, 0) > BUF) |
| 55 | sel_rfd_freeze(netr); |
| 56 | } |
| 57 | |
| 58 | void net_readerr(sel_rfd *rfd, int error) |
| 59 | { |
| 60 | fprintf(stderr, "standard input: read: %s\n", strerror(errno)); |
| 61 | exit(1); |
| 62 | } |
| 63 | |
| 64 | void net_written(sel_wfd *wfd, size_t bufsize) |
| 65 | { |
| 66 | if (bufsize < BUF) |
| 67 | sel_rfd_unfreeze(ptyr); |
| 68 | } |
| 69 | |
| 70 | void net_writeerr(sel_wfd *wfd, int error) |
| 71 | { |
| 72 | fprintf(stderr, "standard input: write: %s\n", strerror(errno)); |
| 73 | exit(1); |
| 74 | } |
| 75 | |
| 76 | void pty_readdata(sel_rfd *rfd, void *data, size_t len) |
| 77 | { |
| 78 | if (len == 0) |
| 79 | exit(0); /* EOF on pty */ |
| 80 | telnet_from_pty(telnet, data, len); |
| 81 | if (sel_write(netw, NULL, 0) > BUF) |
| 82 | sel_rfd_freeze(ptyr); |
| 83 | if (sel_write(ptyw, NULL, 0) > BUF) |
| 84 | sel_rfd_freeze(netr); |
| 85 | } |
| 86 | |
| 87 | void pty_readerr(sel_rfd *rfd, int error) |
| 88 | { |
| 89 | if (error == EIO) /* means EOF, on a pty */ |
| 90 | exit(0); |
| 91 | fprintf(stderr, "pty: read: %s\n", strerror(errno)); |
| 92 | exit(1); |
| 93 | } |
| 94 | |
| 95 | void pty_written(sel_wfd *wfd, size_t bufsize) |
| 96 | { |
| 97 | if (bufsize < BUF) |
| 98 | sel_rfd_unfreeze(netr); |
| 99 | } |
| 100 | |
| 101 | void pty_writeerr(sel_wfd *wfd, int error) |
| 102 | { |
| 103 | fprintf(stderr, "pty: write: %s\n", strerror(errno)); |
| 104 | exit(1); |
| 105 | } |
| 106 | |
| 107 | void sig_readdata(sel_rfd *rfd, void *data, size_t len) |
| 108 | { |
| 109 | char *p = data; |
| 110 | |
| 111 | while (len > 0) { |
| 112 | if (*p == 'C') { |
| 113 | int status; |
| 114 | pid_t pid = waitpid(-1, &status, WNOHANG); |
| 115 | if (WIFEXITED(status) || WIFSIGNALED(status)) |
| 116 | exit(0); /* child process vanished */ |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | void sig_readerr(sel_rfd *rfd, int error) |
| 122 | { |
| 123 | fprintf(stderr, "signal pipe: read: %s\n", strerror(errno)); |
| 124 | exit(1); |
| 125 | } |
| 126 | |
| 127 | int main(int argc, char **argv) |
| 128 | { |
| 129 | int ret; |
| 130 | int shell_started = 0; |
| 131 | char *directory = NULL; |
| 132 | char **program_args = NULL; |
| 133 | |
| 134 | if (argc > 1 && argv[1][0]) { |
| 135 | directory = argv[1]; |
| 136 | argc--, argv++; |
| 137 | } |
| 138 | if (argc > 1) { |
| 139 | program_args = argv + 1; |
| 140 | } |
| 141 | |
| 142 | pty_preinit(); |
| 143 | |
| 144 | asel = sel_new(NULL); |
| 145 | netr = sel_rfd_add(asel, 0, net_readdata, net_readerr, NULL); |
| 146 | netw = sel_wfd_add(asel, 1, net_written, net_writeerr, NULL); |
| 147 | ptyr = sel_rfd_add(asel, -1, pty_readdata, pty_readerr, NULL); |
| 148 | ptyw = sel_wfd_add(asel, -1, pty_written, pty_writeerr, NULL); |
| 149 | |
| 150 | telnet = telnet_new(netw, ptyw); |
| 151 | |
| 152 | if (pipe(signalpipe) < 0) { |
| 153 | perror("pipe"); |
| 154 | return 1; |
| 155 | } |
| 156 | sigr = sel_rfd_add(asel, signalpipe[0], sig_readdata, |
| 157 | sig_readerr, NULL); |
| 158 | |
| 159 | signal(SIGCHLD, sigchld); |
| 160 | |
| 161 | do { |
| 162 | struct shell_data shdata; |
| 163 | |
| 164 | ret = sel_iterate(asel, -1); |
| 165 | if (!shell_started && telnet_shell_ok(telnet, &shdata)) { |
| 166 | ptyfd = run_program_in_pty(&shdata, directory, program_args); |
| 167 | sel_rfd_setfd(ptyr, ptyfd); |
| 168 | sel_wfd_setfd(ptyw, ptyfd); |
| 169 | shell_started = 1; |
| 170 | } |
| 171 | } while (ret == 0); |
| 172 | |
| 173 | return 0; |
| 174 | } |