Bernhard Reutner-Fischer | 2c99851 | 2006-04-12 18:09:26 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
Bernhard Reutner-Fischer | dac7ff1 | 2006-04-12 17:55:51 +0000 | [diff] [blame] | 2 | /* |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 3 | * Simple telnet server |
| 4 | * Bjorn Wesen, Axis Communications AB (bjornw@axis.com) |
| 5 | * |
Rob Landley | 1ec5b29 | 2006-05-29 07:42:02 +0000 | [diff] [blame] | 6 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 7 | * |
| 8 | * --------------------------------------------------------------------------- |
| 9 | * (C) Copyright 2000, Axis Communications AB, LUND, SWEDEN |
| 10 | **************************************************************************** |
| 11 | * |
| 12 | * The telnetd manpage says it all: |
| 13 | * |
| 14 | * Telnetd operates by allocating a pseudo-terminal device (see pty(4)) for |
| 15 | * a client, then creating a login process which has the slave side of the |
| 16 | * pseudo-terminal as stdin, stdout, and stderr. Telnetd manipulates the |
| 17 | * master side of the pseudo-terminal, implementing the telnet protocol and |
| 18 | * passing characters between the remote client and the login process. |
| 19 | * |
| 20 | * Vladimir Oleynik <dzo@simtreas.ru> 2001 |
| 21 | * Set process group corrections, initial busybox port |
| 22 | */ |
| 23 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 24 | #define DEBUG 0 |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 25 | |
Denis Vlasenko | b6adbf1 | 2007-05-26 19:00:18 +0000 | [diff] [blame] | 26 | #include "libbb.h" |
Bernhard Reutner-Fischer | f470196 | 2008-01-27 12:50:12 +0000 | [diff] [blame] | 27 | #include <syslog.h> |
Rob Landley | 099ed50 | 2006-08-28 09:41:49 +0000 | [diff] [blame] | 28 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 29 | #if DEBUG |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 30 | #define TELCMDS |
| 31 | #define TELOPTS |
| 32 | #endif |
| 33 | #include <arpa/telnet.h> |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 34 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 35 | /* Structure that describes a session */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 36 | struct tsession { |
| 37 | struct tsession *next; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 38 | int sockfd_read, sockfd_write, ptyfd; |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 39 | int shell_pid; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 40 | |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 41 | /* two circular buffers */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 42 | /*char *buf1, *buf2;*/ |
| 43 | /*#define TS_BUF1 ts->buf1*/ |
| 44 | /*#define TS_BUF2 TS_BUF2*/ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 45 | #define TS_BUF1 ((unsigned char*)(ts + 1)) |
| 46 | #define TS_BUF2 (((unsigned char*)(ts + 1)) + BUFSIZE) |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 47 | int rdidx1, wridx1, size1; |
| 48 | int rdidx2, wridx2, size2; |
| 49 | }; |
| 50 | |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 51 | /* Two buffers are directly after tsession in malloced memory. |
| 52 | * Make whole thing fit in 4k */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 53 | enum { BUFSIZE = (4 * 1024 - sizeof(struct tsession)) / 2 }; |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 54 | |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 55 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 56 | /* Globals */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 57 | static int maxfd; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 58 | static struct tsession *sessions; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 59 | #if ENABLE_LOGIN |
| 60 | static const char *loginpath = "/bin/login"; |
| 61 | #else |
| 62 | static const char *loginpath = DEFAULT_SHELL; |
| 63 | #endif |
| 64 | static const char *issuefile = "/etc/issue.net"; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 65 | |
| 66 | |
| 67 | /* |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 68 | Remove all IAC's from buf1 (received IACs are ignored and must be removed |
| 69 | so as to not be interpreted by the terminal). Make an uninterrupted |
| 70 | string of characters fit for the terminal. Do this by packing |
| 71 | all characters meant for the terminal sequentially towards the end of buf. |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 72 | |
| 73 | Return a pointer to the beginning of the characters meant for the terminal. |
| 74 | and make *num_totty the number of characters that should be sent to |
| 75 | the terminal. |
| 76 | |
| 77 | Note - If an IAC (3 byte quantity) starts before (bf + len) but extends |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 78 | past (bf + len) then that IAC will be left unprocessed and *processed |
| 79 | will be less than len. |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 80 | |
| 81 | FIXME - if we mean to send 0xFF to the terminal then it will be escaped, |
| 82 | what is the escape character? We aren't handling that situation here. |
| 83 | |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 84 | CR-LF ->'s CR mapping is also done here, for convenience. |
| 85 | |
| 86 | NB: may fail to remove iacs which wrap around buffer! |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 87 | */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 88 | static unsigned char * |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 89 | remove_iacs(struct tsession *ts, int *pnum_totty) |
| 90 | { |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 91 | unsigned char *ptr0 = TS_BUF1 + ts->wridx1; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 92 | unsigned char *ptr = ptr0; |
| 93 | unsigned char *totty = ptr; |
| 94 | unsigned char *end = ptr + MIN(BUFSIZE - ts->wridx1, ts->size1); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 95 | int num_totty; |
| 96 | |
| 97 | while (ptr < end) { |
| 98 | if (*ptr != IAC) { |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 99 | char c = *ptr; |
| 100 | |
| 101 | *totty++ = c; |
| 102 | ptr++; |
Eric Andersen | 3752d33 | 2003-12-19 11:30:13 +0000 | [diff] [blame] | 103 | /* We now map \r\n ==> \r for pragmatic reasons. |
| 104 | * Many client implementations send \r\n when |
| 105 | * the user hits the CarriageReturn key. |
| 106 | */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 107 | if (c == '\r' && ptr < end && (*ptr == '\n' || *ptr == '\0')) |
Eric Andersen | 3752d33 | 2003-12-19 11:30:13 +0000 | [diff] [blame] | 108 | ptr++; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 109 | } else { |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 110 | /* |
| 111 | * TELOPT_NAWS support! |
| 112 | */ |
| 113 | if ((ptr+2) >= end) { |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 114 | /* only the beginning of the IAC is in the |
| 115 | buffer we were asked to process, we can't |
| 116 | process this char. */ |
| 117 | break; |
| 118 | } |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 119 | |
| 120 | /* |
| 121 | * IAC -> SB -> TELOPT_NAWS -> 4-byte -> IAC -> SE |
| 122 | */ |
| 123 | else if (ptr[1] == SB && ptr[2] == TELOPT_NAWS) { |
| 124 | struct winsize ws; |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 125 | |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 126 | if ((ptr+8) >= end) |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame] | 127 | break; /* incomplete, can't process */ |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 128 | ws.ws_col = (ptr[3] << 8) | ptr[4]; |
| 129 | ws.ws_row = (ptr[5] << 8) | ptr[6]; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 130 | ioctl(ts->ptyfd, TIOCSWINSZ, (char *)&ws); |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 131 | ptr += 9; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 132 | } else { |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 133 | /* skip 3-byte IAC non-SB cmd */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 134 | #if DEBUG |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 135 | fprintf(stderr, "Ignoring IAC %s,%s\n", |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 136 | TELCMD(ptr[1]), TELOPT(ptr[2])); |
Glenn L McGrath | 90ed9a0 | 2004-02-22 09:45:57 +0000 | [diff] [blame] | 137 | #endif |
| 138 | ptr += 3; |
| 139 | } |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 140 | } |
| 141 | } |
| 142 | |
Denis Vlasenko | 0de37e1 | 2007-10-17 11:08:53 +0000 | [diff] [blame] | 143 | num_totty = totty - ptr0; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 144 | *pnum_totty = num_totty; |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 145 | /* the difference between ptr and totty is number of iacs |
| 146 | we removed from the stream. Adjust buf1 accordingly. */ |
| 147 | if ((ptr - totty) == 0) /* 99.999% of cases */ |
| 148 | return ptr0; |
| 149 | ts->wridx1 += ptr - totty; |
| 150 | ts->size1 -= ptr - totty; |
| 151 | /* move chars meant for the terminal towards the end of the buffer */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 152 | return memmove(ptr - num_totty, ptr0, num_totty); |
| 153 | } |
| 154 | |
| 155 | |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 156 | static struct tsession * |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 157 | make_new_session( |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 158 | USE_FEATURE_TELNETD_STANDALONE(int sock) |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 159 | SKIP_FEATURE_TELNETD_STANDALONE(void) |
| 160 | ) { |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 161 | const char *login_argv[2]; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 162 | struct termios termbuf; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 163 | int fd, pid; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 164 | char tty_name[32]; |
Rob Landley | 1ec5b29 | 2006-05-29 07:42:02 +0000 | [diff] [blame] | 165 | struct tsession *ts = xzalloc(sizeof(struct tsession) + BUFSIZE * 2); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 166 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 167 | /*ts->buf1 = (char *)(ts + 1);*/ |
| 168 | /*ts->buf2 = ts->buf1 + BUFSIZE;*/ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 169 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 170 | /* Got a new connection, set up a tty. */ |
| 171 | fd = getpty(tty_name, 32); |
| 172 | if (fd < 0) { |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 173 | bb_error_msg("can't create pty"); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 174 | return NULL; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 175 | } |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 176 | if (fd > maxfd) |
| 177 | maxfd = fd; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 178 | ts->ptyfd = fd; |
| 179 | ndelay_on(fd); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 180 | #if ENABLE_FEATURE_TELNETD_STANDALONE |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 181 | ts->sockfd_read = sock; |
| 182 | ndelay_on(sock); |
Denis Vlasenko | 9e23767 | 2007-10-17 11:18:49 +0000 | [diff] [blame] | 183 | if (!sock) { /* We are called with fd 0 - we are in inetd mode */ |
| 184 | sock++; /* so use fd 1 for output */ |
| 185 | ndelay_on(sock); |
| 186 | } |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 187 | ts->sockfd_write = sock; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 188 | if (sock > maxfd) |
| 189 | maxfd = sock; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 190 | #else |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 191 | /* ts->sockfd_read = 0; - done by xzalloc */ |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 192 | ts->sockfd_write = 1; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 193 | ndelay_on(0); |
| 194 | ndelay_on(1); |
| 195 | #endif |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 196 | /* Make the telnet client understand we will echo characters so it |
| 197 | * should not do it locally. We don't tell the client to run linemode, |
| 198 | * because we want to handle line editing and tab completion and other |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 199 | * stuff that requires char-by-char support. */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 200 | { |
| 201 | static const char iacs_to_send[] ALIGN1 = { |
| 202 | IAC, DO, TELOPT_ECHO, |
| 203 | IAC, DO, TELOPT_NAWS, |
| 204 | IAC, DO, TELOPT_LFLOW, |
| 205 | IAC, WILL, TELOPT_ECHO, |
| 206 | IAC, WILL, TELOPT_SGA |
| 207 | }; |
| 208 | memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send)); |
| 209 | ts->rdidx2 = sizeof(iacs_to_send); |
| 210 | ts->size2 = sizeof(iacs_to_send); |
| 211 | } |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 212 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 213 | fflush(NULL); /* flush all streams */ |
| 214 | pid = vfork(); /* NOMMU-friendly */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 215 | if (pid < 0) { |
| 216 | free(ts); |
| 217 | close(fd); |
Denis Vlasenko | 23c8128 | 2007-10-16 22:01:23 +0000 | [diff] [blame] | 218 | /* sock will be closed by caller */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 219 | bb_perror_msg("vfork"); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 220 | return NULL; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 221 | } |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 222 | if (pid > 0) { |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 223 | /* Parent */ |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 224 | ts->shell_pid = pid; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 225 | return ts; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 226 | } |
Denis Vlasenko | f7996f3 | 2007-01-11 17:20:00 +0000 | [diff] [blame] | 227 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 228 | /* Child */ |
| 229 | /* Careful - we are after vfork! */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 230 | |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 231 | /* make new session and process group */ |
Denis Vlasenko | 9af7c9d | 2007-01-19 21:19:35 +0000 | [diff] [blame] | 232 | setsid(); |
Denis Vlasenko | 9af7c9d | 2007-01-19 21:19:35 +0000 | [diff] [blame] | 233 | |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 234 | /* Restore default signal handling */ |
Denis Vlasenko | 25591c3 | 2008-02-16 22:58:56 +0000 | [diff] [blame] | 235 | bb_signals((1 << SIGCHLD) + (1 << SIGPIPE), SIG_DFL); |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 236 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 237 | /* open the child's side of the tty. */ |
Denis Vlasenko | 9af7c9d | 2007-01-19 21:19:35 +0000 | [diff] [blame] | 238 | /* NB: setsid() disconnects from any previous ctty's. Therefore |
| 239 | * we must open child's side of the tty AFTER setsid! */ |
| 240 | fd = xopen(tty_name, O_RDWR); /* becomes our ctty */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 241 | dup2(fd, 0); |
| 242 | dup2(fd, 1); |
| 243 | dup2(fd, 2); |
| 244 | while (fd > 2) close(fd--); |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 245 | tcsetpgrp(0, getpid()); /* switch this tty's process group to us */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 246 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 247 | /* The pseudo-terminal allocated to the client is configured to operate in |
| 248 | * cooked mode, and with XTABS CRMOD enabled (see tty(4)). */ |
| 249 | tcgetattr(0, &termbuf); |
| 250 | termbuf.c_lflag |= ECHO; /* if we use readline we dont want this */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 251 | termbuf.c_oflag |= ONLCR | XTABS; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 252 | termbuf.c_iflag |= ICRNL; |
| 253 | termbuf.c_iflag &= ~IXOFF; |
| 254 | /*termbuf.c_lflag &= ~ICANON;*/ |
| 255 | tcsetattr(0, TCSANOW, &termbuf); |
| 256 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 257 | /* Uses FILE-based I/O to stdout, but does fflush(stdout), |
| 258 | * so should be safe with vfork. |
| 259 | * I fear, though, that some users will have ridiculously big |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 260 | * issue files, and they may block writing to fd 1, |
| 261 | * (parent is supposed to read it, but parent waits |
| 262 | * for vforked child to exec!) */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 263 | print_login_issue(issuefile, NULL); |
| 264 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 265 | /* Exec shell / login / whatever */ |
Denis Vlasenko | 88308fe | 2007-06-25 10:35:11 +0000 | [diff] [blame] | 266 | login_argv[0] = loginpath; |
| 267 | login_argv[1] = NULL; |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 268 | /* exec busybox applet (if PREFER_APPLETS=y), if that fails, |
| 269 | * exec external program */ |
| 270 | BB_EXECVP(loginpath, (char **)login_argv); |
| 271 | /* _exit is safer with vfork, and we shouldn't send message |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 272 | * to remote clients anyway */ |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 273 | _exit(1); /*bb_perror_msg_and_die("execv %s", loginpath);*/ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 274 | } |
| 275 | |
Denis Vlasenko | e87b868 | 2007-10-17 14:33:31 +0000 | [diff] [blame] | 276 | /* Must match getopt32 string */ |
| 277 | enum { |
| 278 | OPT_WATCHCHILD = (1 << 2), /* -K */ |
| 279 | OPT_INETD = (1 << 3) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -i */ |
| 280 | OPT_PORT = (1 << 4) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -p */ |
| 281 | OPT_FOREGROUND = (1 << 6) * ENABLE_FEATURE_TELNETD_STANDALONE, /* -F */ |
| 282 | }; |
| 283 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 284 | #if ENABLE_FEATURE_TELNETD_STANDALONE |
| 285 | |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 286 | static void |
| 287 | free_session(struct tsession *ts) |
| 288 | { |
| 289 | struct tsession *t = sessions; |
| 290 | |
Denis Vlasenko | e87b868 | 2007-10-17 14:33:31 +0000 | [diff] [blame] | 291 | if (option_mask32 & OPT_INETD) |
| 292 | exit(0); |
| 293 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 294 | /* Unlink this telnet session from the session list */ |
Mike Frysinger | 731f81c | 2006-05-10 15:23:12 +0000 | [diff] [blame] | 295 | if (t == ts) |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 296 | sessions = ts->next; |
| 297 | else { |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 298 | while (t->next != ts) |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 299 | t = t->next; |
| 300 | t->next = ts->next; |
| 301 | } |
| 302 | |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 303 | #if 0 |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 304 | /* It was said that "normal" telnetd just closes ptyfd, |
| 305 | * doesn't send SIGKILL. When we close ptyfd, |
| 306 | * kernel sends SIGHUP to processes having slave side opened. */ |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 307 | kill(ts->shell_pid, SIGKILL); |
| 308 | wait4(ts->shell_pid, NULL, 0, NULL); |
| 309 | #endif |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 310 | close(ts->ptyfd); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 311 | close(ts->sockfd_read); |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 312 | /* We do not need to close(ts->sockfd_write), it's the same |
| 313 | * as sockfd_read unless we are in inetd mode. But in inetd mode |
Denis Vlasenko | e87b868 | 2007-10-17 14:33:31 +0000 | [diff] [blame] | 314 | * we do not reach this */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 315 | free(ts); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 316 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 317 | /* Scan all sessions and find new maxfd */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 318 | maxfd = 0; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 319 | ts = sessions; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 320 | while (ts) { |
| 321 | if (maxfd < ts->ptyfd) |
| 322 | maxfd = ts->ptyfd; |
| 323 | if (maxfd < ts->sockfd_read) |
| 324 | maxfd = ts->sockfd_read; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 325 | #if 0 |
| 326 | /* Again, sockfd_write == sockfd_read here */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 327 | if (maxfd < ts->sockfd_write) |
| 328 | maxfd = ts->sockfd_write; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 329 | #endif |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 330 | ts = ts->next; |
| 331 | } |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 332 | } |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 333 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 334 | #else /* !FEATURE_TELNETD_STANDALONE */ |
| 335 | |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 336 | /* Used in main() only, thus "return 0" actually is exit(0). */ |
Denis Vlasenko | e87b868 | 2007-10-17 14:33:31 +0000 | [diff] [blame] | 337 | #define free_session(ts) return 0 |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 338 | |
| 339 | #endif |
| 340 | |
Denis Vlasenko | 68404f1 | 2008-03-17 09:00:54 +0000 | [diff] [blame^] | 341 | static void handle_sigchld(int sig ATTRIBUTE_UNUSED) |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 342 | { |
| 343 | pid_t pid; |
| 344 | struct tsession *ts; |
| 345 | |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 346 | /* Looping: more than one child may have exited */ |
| 347 | while (1) { |
Denis Vlasenko | fb0eba7 | 2008-01-02 19:55:04 +0000 | [diff] [blame] | 348 | pid = wait_any_nohang(NULL); |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 349 | if (pid <= 0) |
| 350 | break; |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 351 | ts = sessions; |
| 352 | while (ts) { |
| 353 | if (ts->shell_pid == pid) { |
| 354 | ts->shell_pid = -1; |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 355 | break; |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 356 | } |
| 357 | ts = ts->next; |
| 358 | } |
| 359 | } |
| 360 | } |
| 361 | |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 362 | int telnetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Denis Vlasenko | 68404f1 | 2008-03-17 09:00:54 +0000 | [diff] [blame^] | 363 | int telnetd_main(int argc ATTRIBUTE_UNUSED, char **argv) |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 364 | { |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 365 | fd_set rdfdset, wrfdset; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 366 | unsigned opt; |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 367 | int count; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 368 | struct tsession *ts; |
| 369 | #if ENABLE_FEATURE_TELNETD_STANDALONE |
| 370 | #define IS_INETD (opt & OPT_INETD) |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 371 | int master_fd = master_fd; /* be happy, gcc */ |
Denis Vlasenko | 1385899 | 2006-10-08 12:49:22 +0000 | [diff] [blame] | 372 | unsigned portnbr = 23; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 373 | char *opt_bindaddr = NULL; |
| 374 | char *opt_portnbr; |
| 375 | #else |
| 376 | enum { |
| 377 | IS_INETD = 1, |
| 378 | master_fd = -1, |
| 379 | portnbr = 23, |
| 380 | }; |
Glenn L McGrath | c2b9186 | 2003-09-12 11:27:15 +0000 | [diff] [blame] | 381 | #endif |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 382 | /* Even if !STANDALONE, we accept (and ignore) -i, thus people |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 383 | * don't need to guess whether it's ok to pass -i to us */ |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 384 | opt = getopt32(argv, "f:l:Ki" USE_FEATURE_TELNETD_STANDALONE("p:b:F"), |
Denis Vlasenko | 0e87d34 | 2006-09-22 08:50:29 +0000 | [diff] [blame] | 385 | &issuefile, &loginpath |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 386 | USE_FEATURE_TELNETD_STANDALONE(, &opt_portnbr, &opt_bindaddr)); |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 387 | if (!IS_INETD /*&& !re_execed*/) { |
| 388 | /* inform that we start in standalone mode? |
| 389 | * May be useful when people forget to give -i */ |
| 390 | /*bb_error_msg("listening for connections");*/ |
| 391 | if (!(opt & OPT_FOREGROUND)) { |
| 392 | /* DAEMON_CHDIR_ROOT was giving inconsistent |
Denis Vlasenko | 008eda2 | 2007-10-16 10:47:27 +0000 | [diff] [blame] | 393 | * behavior with/without -F, -i */ |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 394 | bb_daemonize_or_rexec(0 /*was DAEMON_CHDIR_ROOT*/, argv); |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 395 | } |
| 396 | } |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 397 | /* Redirect log to syslog early, if needed */ |
| 398 | if (IS_INETD || !(opt & OPT_FOREGROUND)) { |
| 399 | openlog(applet_name, 0, LOG_USER); |
| 400 | logmode = LOGMODE_SYSLOG; |
| 401 | } |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 402 | USE_FEATURE_TELNETD_STANDALONE( |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 403 | if (opt & OPT_PORT) |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 404 | portnbr = xatou16(opt_portnbr); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 405 | ); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 406 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 407 | /* Used to check access(loginpath, X_OK) here. Pointless. |
| 408 | * exec will do this for us for free later. */ |
Glenn L McGrath | 9e5d6c0 | 2003-01-21 20:55:56 +0000 | [diff] [blame] | 409 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 410 | #if ENABLE_FEATURE_TELNETD_STANDALONE |
| 411 | if (IS_INETD) { |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 412 | sessions = make_new_session(0); |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 413 | if (!sessions) /* pty opening or vfork problem, exit */ |
| 414 | return 1; /* make_new_session prints error message */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 415 | } else { |
Denis Vlasenko | 9de420c | 2007-01-10 09:28:01 +0000 | [diff] [blame] | 416 | master_fd = create_and_bind_stream_or_die(opt_bindaddr, portnbr); |
Denis Vlasenko | c8717cd | 2006-11-22 16:10:39 +0000 | [diff] [blame] | 417 | xlisten(master_fd, 1); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 418 | } |
Rob Landley | 00e76cb | 2005-05-10 23:53:33 +0000 | [diff] [blame] | 419 | #else |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 420 | sessions = make_new_session(); |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 421 | if (!sessions) /* pty opening or vfork problem, exit */ |
| 422 | return 1; /* make_new_session prints error message */ |
Rob Landley | 00e76cb | 2005-05-10 23:53:33 +0000 | [diff] [blame] | 423 | #endif |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 424 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 425 | /* We don't want to die if just one session is broken */ |
| 426 | signal(SIGPIPE, SIG_IGN); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 427 | |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 428 | if (opt & OPT_WATCHCHILD) |
| 429 | signal(SIGCHLD, handle_sigchld); |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 430 | else /* prevent dead children from becoming zombies */ |
| 431 | signal(SIGCHLD, SIG_IGN); |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 432 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 433 | /* |
| 434 | This is how the buffers are used. The arrows indicate the movement |
| 435 | of data. |
| 436 | +-------+ wridx1++ +------+ rdidx1++ +----------+ |
| 437 | | | <-------------- | buf1 | <-------------- | | |
| 438 | | | size1-- +------+ size1++ | | |
| 439 | | pty | | socket | |
| 440 | | | rdidx2++ +------+ wridx2++ | | |
| 441 | | | --------------> | buf2 | --------------> | | |
| 442 | +-------+ size2++ +------+ size2-- +----------+ |
| 443 | |
| 444 | size1: "how many bytes are buffered for pty between rdidx1 and wridx1?" |
| 445 | size2: "how many bytes are buffered for socket between rdidx2 and wridx2?" |
| 446 | |
| 447 | Each session has got two buffers. Buffers are circular. If sizeN == 0, |
| 448 | buffer is empty. If sizeN == BUFSIZE, buffer is full. In both these cases |
| 449 | rdidxN == wridxN. |
| 450 | */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 451 | again: |
| 452 | FD_ZERO(&rdfdset); |
| 453 | FD_ZERO(&wrfdset); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 454 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 455 | /* Select on the master socket, all telnet sockets and their |
| 456 | * ptys if there is room in their session buffers. |
| 457 | * NB: scalability problem: we recalculate entire bitmap |
| 458 | * before each select. Can be a problem with 500+ connections. */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 459 | ts = sessions; |
| 460 | while (ts) { |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 461 | struct tsession *next = ts->next; /* in case we free ts. */ |
| 462 | if (ts->shell_pid == -1) { |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 463 | /* Child died and we detected that */ |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 464 | free_session(ts); |
| 465 | } else { |
| 466 | if (ts->size1 > 0) /* can write to pty */ |
| 467 | FD_SET(ts->ptyfd, &wrfdset); |
| 468 | if (ts->size1 < BUFSIZE) /* can read from socket */ |
| 469 | FD_SET(ts->sockfd_read, &rdfdset); |
| 470 | if (ts->size2 > 0) /* can write to socket */ |
| 471 | FD_SET(ts->sockfd_write, &wrfdset); |
| 472 | if (ts->size2 < BUFSIZE) /* can read from pty */ |
| 473 | FD_SET(ts->ptyfd, &rdfdset); |
| 474 | } |
| 475 | ts = next; |
| 476 | } |
| 477 | if (!IS_INETD) { |
| 478 | FD_SET(master_fd, &rdfdset); |
| 479 | /* This is needed because free_session() does not |
Denis Vlasenko | 018b155 | 2007-11-06 01:38:46 +0000 | [diff] [blame] | 480 | * take master_fd into account when it finds new |
Denis Vlasenko | 2450c45 | 2007-10-15 22:09:15 +0000 | [diff] [blame] | 481 | * maxfd among remaining fd's */ |
| 482 | if (master_fd > maxfd) |
| 483 | maxfd = master_fd; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 484 | } |
| 485 | |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 486 | count = select(maxfd + 1, &rdfdset, &wrfdset, NULL, NULL); |
| 487 | if (count < 0) |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 488 | goto again; /* EINTR or ENOMEM */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 489 | |
| 490 | #if ENABLE_FEATURE_TELNETD_STANDALONE |
| 491 | /* First check for and accept new sessions. */ |
| 492 | if (!IS_INETD && FD_ISSET(master_fd, &rdfdset)) { |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 493 | int fd; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 494 | struct tsession *new_ts; |
| 495 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 496 | fd = accept(master_fd, NULL, NULL); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 497 | if (fd < 0) |
| 498 | goto again; |
| 499 | /* Create a new session and link it into our active list */ |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 500 | new_ts = make_new_session(fd); |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 501 | if (new_ts) { |
| 502 | new_ts->next = sessions; |
| 503 | sessions = new_ts; |
| 504 | } else { |
| 505 | close(fd); |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 506 | } |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 507 | } |
| 508 | #endif |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 509 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 510 | /* Then check for data tunneling. */ |
| 511 | ts = sessions; |
| 512 | while (ts) { /* For all sessions... */ |
| 513 | struct tsession *next = ts->next; /* in case we free ts. */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 514 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 515 | if (/*ts->size1 &&*/ FD_ISSET(ts->ptyfd, &wrfdset)) { |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 516 | int num_totty; |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 517 | unsigned char *ptr; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 518 | /* Write to pty from buffer 1. */ |
| 519 | ptr = remove_iacs(ts, &num_totty); |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 520 | count = safe_write(ts->ptyfd, ptr, num_totty); |
| 521 | if (count < 0) { |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 522 | if (errno == EAGAIN) |
| 523 | goto skip1; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 524 | goto kill_session; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 525 | } |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 526 | ts->size1 -= count; |
| 527 | ts->wridx1 += count; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 528 | if (ts->wridx1 >= BUFSIZE) /* actually == BUFSIZE */ |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 529 | ts->wridx1 = 0; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 530 | } |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 531 | skip1: |
| 532 | if (/*ts->size2 &&*/ FD_ISSET(ts->sockfd_write, &wrfdset)) { |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 533 | /* Write to socket from buffer 2. */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 534 | count = MIN(BUFSIZE - ts->wridx2, ts->size2); |
| 535 | count = safe_write(ts->sockfd_write, TS_BUF2 + ts->wridx2, count); |
| 536 | if (count < 0) { |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 537 | if (errno == EAGAIN) |
| 538 | goto skip2; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 539 | goto kill_session; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 540 | } |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 541 | ts->size2 -= count; |
| 542 | ts->wridx2 += count; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 543 | if (ts->wridx2 >= BUFSIZE) /* actually == BUFSIZE */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 544 | ts->wridx2 = 0; |
| 545 | } |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 546 | skip2: |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 547 | /* Should not be needed, but... remove_iacs is actually buggy |
| 548 | * (it cannot process iacs which wrap around buffer's end)! |
| 549 | * Since properly fixing it requires writing bigger code, |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 550 | * we rely instead on this code making it virtually impossible |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 551 | * to have wrapped iac (people don't type at 2k/second). |
| 552 | * It also allows for bigger reads in common case. */ |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 553 | if (ts->size1 == 0) { |
| 554 | ts->rdidx1 = 0; |
| 555 | ts->wridx1 = 0; |
| 556 | } |
| 557 | if (ts->size2 == 0) { |
| 558 | ts->rdidx2 = 0; |
| 559 | ts->wridx2 = 0; |
| 560 | } |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 561 | |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 562 | if (/*ts->size1 < BUFSIZE &&*/ FD_ISSET(ts->sockfd_read, &rdfdset)) { |
| 563 | /* Read from socket to buffer 1. */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 564 | count = MIN(BUFSIZE - ts->rdidx1, BUFSIZE - ts->size1); |
| 565 | count = safe_read(ts->sockfd_read, TS_BUF1 + ts->rdidx1, count); |
| 566 | if (count <= 0) { |
| 567 | if (count < 0 && errno == EAGAIN) |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 568 | goto skip3; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 569 | goto kill_session; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 570 | } |
| 571 | /* Ignore trailing NUL if it is there */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 572 | if (!TS_BUF1[ts->rdidx1 + count - 1]) { |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 573 | --count; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 574 | } |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 575 | ts->size1 += count; |
| 576 | ts->rdidx1 += count; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 577 | if (ts->rdidx1 >= BUFSIZE) /* actually == BUFSIZE */ |
| 578 | ts->rdidx1 = 0; |
| 579 | } |
| 580 | skip3: |
| 581 | if (/*ts->size2 < BUFSIZE &&*/ FD_ISSET(ts->ptyfd, &rdfdset)) { |
| 582 | /* Read from pty to buffer 2. */ |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 583 | count = MIN(BUFSIZE - ts->rdidx2, BUFSIZE - ts->size2); |
| 584 | count = safe_read(ts->ptyfd, TS_BUF2 + ts->rdidx2, count); |
| 585 | if (count <= 0) { |
| 586 | if (count < 0 && errno == EAGAIN) |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 587 | goto skip4; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 588 | goto kill_session; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 589 | } |
Denis Vlasenko | 10916c5 | 2007-10-15 17:28:00 +0000 | [diff] [blame] | 590 | ts->size2 += count; |
| 591 | ts->rdidx2 += count; |
Denis Vlasenko | 59d7c43 | 2007-10-15 15:19:36 +0000 | [diff] [blame] | 592 | if (ts->rdidx2 >= BUFSIZE) /* actually == BUFSIZE */ |
| 593 | ts->rdidx2 = 0; |
| 594 | } |
| 595 | skip4: |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 596 | ts = next; |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 597 | continue; |
| 598 | kill_session: |
| 599 | free_session(ts); |
| 600 | ts = next; |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 601 | } |
Denis Vlasenko | f472b23 | 2007-10-16 21:35:17 +0000 | [diff] [blame] | 602 | |
Denis Vlasenko | 75f8d08 | 2006-11-22 15:54:52 +0000 | [diff] [blame] | 603 | goto again; |
Eric Andersen | 08a7220 | 2002-09-30 20:52:10 +0000 | [diff] [blame] | 604 | } |