/* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)utility.c 8.2 (Berkeley) 12/15/93"; #endif static const char rcsid[] = "$FreeBSD: src/libexec/telnetd/utility.c,v 1.15 2001/07/20 15:14:03 ru Exp $"; #endif /* not lint */ #ifdef __FreeBSD__ #include #include #endif #define PRINTOPTIONS #include "telnetd.h" /* * utility functions performing io related tasks */ /* * ttloop * * A small subroutine to flush the network output buffer, get some data * from the network, and pass it through the telnet state machine. We * also flush the pty input buffer (by dropping its data) if it becomes * too full. */ void ttloop() { DIAG(TD_REPORT, output_data("td: ttloop\r\n")); if (nfrontp - nbackp > 0) { netflush(); } ncc = read(net, netibuf, sizeof netibuf); if (ncc < 0) { syslog(LOG_INFO, "ttloop: read: %m"); exit(1); } else if (ncc == 0) { syslog(LOG_INFO, "ttloop: peer died: %m"); exit(1); } DIAG(TD_REPORT, output_data("td: ttloop read %d chars\r\n", ncc)); netip = netibuf; telrcv(); /* state machine */ if (ncc > 0) { pfrontp = pbackp = ptyobuf; telrcv(); } } /* end of ttloop */ /* * Check a descriptor to see if out of band data exists on it. */ int stilloob(s) int s; /* socket number */ { static struct timeval timeout = { 0 }; fd_set excepts; int value; do { FD_ZERO(&excepts); FD_SET(s, &excepts); memset((char *)&timeout, 0, sizeof timeout); value = select(s+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout); } while ((value == -1) && (errno == EINTR)); if (value < 0) { fatalperror(pty, "select"); } if (FD_ISSET(s, &excepts)) { return 1; } else { return 0; } } void ptyflush() { int n; if ((n = pfrontp - pbackp) > 0) { DIAG(TD_REPORT | TD_PTYDATA, output_data("td: ptyflush %d chars\r\n", n)); DIAG(TD_PTYDATA, printdata("pd", pbackp, n)); n = write(pty, pbackp, n); } if (n < 0) { if (errno == EWOULDBLOCK || errno == EINTR) return; cleanup(0); } pbackp += n; if (pbackp == pfrontp) pbackp = pfrontp = ptyobuf; } /* * nextitem() * * Return the address of the next "item" in the TELNET data * stream. This will be the address of the next character if * the current address is a user data character, or it will * be the address of the character following the TELNET command * if the current address is a TELNET IAC ("I Am a Command") * character. */ char * nextitem(current) char *current; { if ((*current&0xff) != IAC) { return current+1; } switch (*(current+1)&0xff) { case DO: case DONT: case WILL: case WONT: return current+3; case SB: /* loop forever looking for the SE */ { register char *look = current+2; for (;;) { if ((*look++&0xff) == IAC) { if ((*look++&0xff) == SE) { return look; } } } } default: return current+2; } } /* end of nextitem */ /* * netclear() * * We are about to do a TELNET SYNCH operation. Clear * the path to the network. * * Things are a bit tricky since we may have sent the first * byte or so of a previous TELNET command into the network. * So, we have to scan the network buffer from the beginning * until we are up to where we want to be. * * A side effect of what we do, just to keep things * simple, is to clear the urgent data pointer. The principal * caller should be setting the urgent data pointer AFTER calling * us in any case. */ void netclear() { register char *thisitem, *next; char *good; #define wewant(p) ((nfrontp > p) && ((*p&0xff) == IAC) && \ ((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL)) thisitem = netobuf; while ((next = nextitem(thisitem)) <= nbackp) { thisitem = next; } /* Now, thisitem is first before/at boundary. */ good = netobuf; /* where the good bytes go */ while (nfrontp > thisitem) { if (wewant(thisitem)) { int length; next = thisitem; do { next = nextitem(next); } while (wewant(next) && (nfrontp > next)); length = next-thisitem; bcopy(thisitem, good, length); good += length; thisitem = next; } else { thisitem = nextitem(thisitem); } } nbackp = netobuf; nfrontp = good; /* next byte to be sent */ neturg = 0; } /* end of netclear */ /* * netflush * Send as much data as possible to the network, * handling requests for urgent data. */ void netflush() { int n; extern int not42; while ((n = nfrontp - nbackp) > 0) { #if 0 /* XXX This causes output_data() to recurse and die */ DIAG(TD_REPORT, { n += output_data("td: netflush %d chars\r\n", n); }); #endif /* * if no urgent data, or if the other side appears to be an * old 4.2 client (and thus unable to survive TCP urgent data), * write the entire buffer in non-OOB mode. */ if ((neturg == 0) || (not42 == 0)) { n = write(net, nbackp, n); /* normal write */ } else { n = neturg - nbackp; /* * In 4.2 (and 4.3) systems, there is some question about * what byte in a sendOOB operation is the "OOB" data. * To make ourselves compatible, we only send ONE byte * out of band, the one WE THINK should be OOB (though * we really have more the TCP philosophy of urgent data * rather than the Unix philosophy of OOB data). */ if (n > 1) { n = send(net, nbackp, n-1, 0); /* send URGENT all by itself */ } else { n = send(net, nbackp, n, MSG_OOB); /* URGENT data */ } } if (n == -1) { if (errno == EWOULDBLOCK || errno == EINTR) continue; cleanup(0); /* NOTREACHED */ } nbackp += n; if (nbackp >= neturg) { neturg = 0; } if (nbackp == nfrontp) { nbackp = nfrontp = netobuf; } } return; } /* end of netflush */ /* * miscellaneous functions doing a variety of little jobs follow ... */ void fatal(f, msg) int f; char *msg; { char buf[BUFSIZ]; (void) snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg); (void) write(f, buf, (int)strlen(buf)); sleep(1); /*XXX*/ exit(1); } void fatalperror(f, msg) int f; char *msg; { char buf[BUFSIZ], *strerror(); (void) snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(errno)); fatal(f, buf); } char editedhost[32]; void edithost(pat, host) register char *pat; register char *host; { register char *res = editedhost; if (!pat) pat = ""; while (*pat) { switch (*pat) { case '#': if (*host) host++; break; case '@': if (*host) *res++ = *host++; break; default: *res++ = *pat; break; } if (res == &editedhost[sizeof editedhost - 1]) { *res = '\0'; return; } pat++; } if (*host) (void) strncpy(res, host, sizeof editedhost - (res - editedhost) -1); else *res = '\0'; editedhost[sizeof editedhost - 1] = '\0'; } static char *putlocation; void putstr(s) register char *s; { while (*s) putchr(*s++); } void putchr(cc) int cc; { *putlocation++ = cc; } #ifdef __FreeBSD__ static char fmtstr[] = { "%+" }; #else /* * This is split on two lines so that SCCS will not see the M * between two % signs and expand it... */ static char fmtstr[] = { "%l:%M\ %P on %A, %d %B %Y" }; #endif void putf(cp, where) register char *cp; char *where; { char *slash; time_t t; char db[100]; #ifdef STREAMSPTY extern char *index(); #else extern char *rindex(); #endif #ifdef __FreeBSD__ static struct utsname kerninfo; if (!*kerninfo.sysname) uname(&kerninfo); #endif putlocation = where; while (*cp) { if (*cp =='\n') { putstr("\r\n"); cp++; continue; } else if (*cp != '%') { putchr(*cp++); continue; } switch (*++cp) { case 't': #ifdef STREAMSPTY /* names are like /dev/pts/2 -- we want pts/2 */ slash = index(line+1, '/'); #else slash = rindex(line, '/'); #endif if (slash == (char *) 0) putstr(line); else putstr(&slash[1]); break; case 'h': putstr(editedhost); break; case 'd': #ifdef __FreeBSD__ setlocale(LC_TIME, ""); #endif (void)time(&t); (void)strftime(db, sizeof(db), fmtstr, localtime(&t)); putstr(db); break; #ifdef __FreeBSD__ case 's': putstr(kerninfo.sysname); break; case 'm': putstr(kerninfo.machine); break; case 'r': putstr(kerninfo.release); break; case 'v': putstr(kerninfo.version); break; #endif case '%': putchr('%'); break; } cp++; } } #ifdef DIAGNOSTICS /* * Print telnet options and commands in plain text, if possible. */ void printoption(fmt, option) register char *fmt; register int option; { if (TELOPT_OK(option)) output_data("%s %s\r\n", fmt, TELOPT(option)); else if (TELCMD_OK(option)) output_data("%s %s\r\n", fmt, TELCMD(option)); else output_data("%s %d\r\n", fmt, option); return; } void printsub(direction, pointer, length) char direction; /* '<' or '>' */ unsigned char *pointer; /* where suboption data sits */ int length; /* length of suboption data */ { register int i = 0; if (!(diagnostic & TD_OPTIONS)) return; if (direction) { output_data("td: %s suboption ", direction == '<' ? "recv" : "send"); if (length >= 3) { register int j; i = pointer[length-2]; j = pointer[length-1]; if (i != IAC || j != SE) { output_data("(terminated by "); if (TELOPT_OK(i)) output_data("%s ", TELOPT(i)); else if (TELCMD_OK(i)) output_data("%s ", TELCMD(i)); else output_data("%d ", i); if (TELOPT_OK(j)) output_data("%s", TELOPT(j)); else if (TELCMD_OK(j)) output_data("%s", TELCMD(j)); else output_data("%d", j); output_data(", not IAC SE!) "); } } length -= 2; } if (length < 1) { output_data("(Empty suboption??\?)"); return; } switch (pointer[0]) { case TELOPT_TTYPE: output_data("TERMINAL-TYPE "); switch (pointer[1]) { case TELQUAL_IS: output_data("IS \"%.*s\"", length-2, (char *)pointer+2); break; case TELQUAL_SEND: output_data("SEND"); break; default: output_data( "- unknown qualifier %d (0x%x).", pointer[1], pointer[1]); } break; case TELOPT_TSPEED: output_data("TERMINAL-SPEED"); if (length < 2) { output_data(" (empty suboption??\?)"); break; } switch (pointer[1]) { case TELQUAL_IS: output_data(" IS %.*s", length-2, (char *)pointer+2); break; default: if (pointer[1] == 1) output_data(" SEND"); else output_data(" %d (unknown)", pointer[1]); for (i = 2; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; } break; case TELOPT_LFLOW: output_data("TOGGLE-FLOW-CONTROL"); if (length < 2) { output_data(" (empty suboption??\?)"); break; } switch (pointer[1]) { case LFLOW_OFF: output_data(" OFF"); break; case LFLOW_ON: output_data(" ON"); break; case LFLOW_RESTART_ANY: output_data(" RESTART-ANY"); break; case LFLOW_RESTART_XON: output_data(" RESTART-XON"); break; default: output_data(" %d (unknown)", pointer[1]); } for (i = 2; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; case TELOPT_NAWS: output_data("NAWS"); if (length < 2) { output_data(" (empty suboption??\?)"); break; } if (length == 2) { output_data(" ?%d?", pointer[1]); break; } output_data(" %d %d (%d)", pointer[1], pointer[2], (int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2]))); if (length == 4) { output_data(" ?%d?", pointer[3]); break; } output_data(" %d %d (%d)", pointer[3], pointer[4], (int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4]))); for (i = 5; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; case TELOPT_LINEMODE: output_data("LINEMODE "); if (length < 2) { output_data(" (empty suboption??\?)"); break; } switch (pointer[1]) { case WILL: output_data("WILL "); goto common; case WONT: output_data("WONT "); goto common; case DO: output_data("DO "); goto common; case DONT: output_data("DONT "); common: if (length < 3) { output_data("(no option??\?)"); break; } switch (pointer[2]) { case LM_FORWARDMASK: output_data("Forward Mask"); for (i = 3; i < length; i++) { output_data(" %x", pointer[i]); } break; default: output_data("%d (unknown)", pointer[2]); for (i = 3; i < length; i++) { output_data(" %d", pointer[i]); } break; } break; case LM_SLC: output_data("SLC"); for (i = 2; i < length - 2; i += 3) { if (SLC_NAME_OK(pointer[i+SLC_FUNC])) output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC])); else output_data(" %d", pointer[i+SLC_FUNC]); switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) { case SLC_NOSUPPORT: output_data(" NOSUPPORT"); break; case SLC_CANTCHANGE: output_data(" CANTCHANGE"); break; case SLC_VARIABLE: output_data(" VARIABLE"); break; case SLC_DEFAULT: output_data(" DEFAULT"); break; } output_data("%s%s%s", pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "", pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "", pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : ""); if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN| SLC_FLUSHOUT| SLC_LEVELBITS)) { output_data("(0x%x)", pointer[i+SLC_FLAGS]); } output_data(" %d;", pointer[i+SLC_VALUE]); if ((pointer[i+SLC_VALUE] == IAC) && (pointer[i+SLC_VALUE+1] == IAC)) i++; } for (; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; case LM_MODE: output_data("MODE "); if (length < 3) { output_data("(no mode??\?)"); break; } { char tbuf[32]; sprintf(tbuf, "%s%s%s%s%s", pointer[2]&MODE_EDIT ? "|EDIT" : "", pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "", pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "", pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "", pointer[2]&MODE_ACK ? "|ACK" : ""); output_data("%s", tbuf[1] ? &tbuf[1] : "0"); } if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) { output_data(" (0x%x)", pointer[2]); } for (i = 3; i < length; i++) { output_data(" ?0x%x?", pointer[i]); } break; default: output_data("%d (unknown)", pointer[1]); for (i = 2; i < length; i++) { output_data(" %d", pointer[i]); } } break; case TELOPT_STATUS: { register char *cp; register int j, k; output_data("STATUS"); switch (pointer[1]) { default: if (pointer[1] == TELQUAL_SEND) output_data(" SEND"); else output_data(" %d (unknown)", pointer[1]); for (i = 2; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; case TELQUAL_IS: output_data(" IS\r\n"); for (i = 2; i < length; i++) { switch(pointer[i]) { case DO: cp = "DO"; goto common2; case DONT: cp = "DONT"; goto common2; case WILL: cp = "WILL"; goto common2; case WONT: cp = "WONT"; goto common2; common2: i++; if (TELOPT_OK(pointer[i])) output_data(" %s %s", cp, TELOPT(pointer[i])); else output_data(" %s %d", cp, pointer[i]); output_data("\r\n"); break; case SB: output_data(" SB "); i++; j = k = i; while (j < length) { if (pointer[j] == SE) { if (j+1 == length) break; if (pointer[j+1] == SE) j++; else break; } pointer[k++] = pointer[j++]; } printsub(0, &pointer[i], k - i); if (i < length) { output_data(" SE"); i = j; } else i = j - 1; output_data("\r\n"); break; default: output_data(" %d", pointer[i]); break; } } break; } break; } case TELOPT_XDISPLOC: output_data("X-DISPLAY-LOCATION "); switch (pointer[1]) { case TELQUAL_IS: output_data("IS \"%.*s\"", length-2, (char *)pointer+2); break; case TELQUAL_SEND: output_data("SEND"); break; default: output_data("- unknown qualifier %d (0x%x).", pointer[1], pointer[1]); } break; case TELOPT_NEW_ENVIRON: output_data("NEW-ENVIRON "); goto env_common1; case TELOPT_OLD_ENVIRON: output_data("OLD-ENVIRON"); env_common1: switch (pointer[1]) { case TELQUAL_IS: output_data("IS "); goto env_common; case TELQUAL_SEND: output_data("SEND "); goto env_common; case TELQUAL_INFO: output_data("INFO "); env_common: { register int noquote = 2; for (i = 2; i < length; i++ ) { switch (pointer[i]) { case NEW_ENV_VAR: output_data("\" VAR " + noquote); noquote = 2; break; case NEW_ENV_VALUE: output_data("\" VALUE " + noquote); noquote = 2; break; case ENV_ESC: output_data("\" ESC " + noquote); noquote = 2; break; case ENV_USERVAR: output_data("\" USERVAR " + noquote); noquote = 2; break; default: if (isprint(pointer[i]) && pointer[i] != '"') { if (noquote) { output_data("\""); noquote = 0; } output_data("%c", pointer[i]); } else { output_data("\" %03o " + noquote, pointer[i]); noquote = 2; } break; } } if (!noquote) output_data("\""); break; } } break; #if defined(AUTHENTICATION) case TELOPT_AUTHENTICATION: output_data("AUTHENTICATION"); if (length < 2) { output_data(" (empty suboption??\?)"); break; } switch (pointer[1]) { case TELQUAL_REPLY: case TELQUAL_IS: output_data(" %s ", (pointer[1] == TELQUAL_IS) ? "IS" : "REPLY"); if (AUTHTYPE_NAME_OK(pointer[2])) output_data("%s ", AUTHTYPE_NAME(pointer[2])); else output_data("%d ", pointer[2]); if (length < 3) { output_data("(partial suboption??\?)"); break; } output_data("%s|%s", ((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ? "CLIENT" : "SERVER", ((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ? "MUTUAL" : "ONE-WAY"); { char buf[512]; auth_printsub(&pointer[1], length - 1, buf, sizeof(buf)); output_data("%s", buf); } break; case TELQUAL_SEND: i = 2; output_data(" SEND "); while (i < length) { if (AUTHTYPE_NAME_OK(pointer[i])) output_data("%s ", AUTHTYPE_NAME(pointer[i])); else output_data("%d ", pointer[i]); if (++i >= length) { output_data("(partial suboption??\?)"); break; } output_data("%s|%s ", ((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ? "CLIENT" : "SERVER", ((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ? "MUTUAL" : "ONE-WAY"); ++i; } break; case TELQUAL_NAME: output_data(" NAME \"%.*s\"", length - 2, pointer + 2); break; default: for (i = 2; i < length; i++) { output_data(" ?%d?", pointer[i]); } break; } break; #endif default: if (TELOPT_OK(pointer[0])) output_data("%s (unknown)", TELOPT(pointer[0])); else output_data("%d (unknown)", pointer[i]); for (i = 1; i < length; i++) { output_data(" %d", pointer[i]); } break; } output_data("\r\n"); } /* * Dump a data buffer in hex and ascii to the output data stream. */ void printdata(tag, ptr, cnt) register char *tag; register char *ptr; register int cnt; { register int i; char xbuf[30]; while (cnt) { /* flush net output buffer if no room for new data) */ if ((&netobuf[BUFSIZ] - nfrontp) < 80) { netflush(); } /* add a line of output */ output_data("%s: ", tag); for (i = 0; i < 20 && cnt; i++) { output_data("%02x", *ptr); if (isprint(*ptr)) { xbuf[i] = *ptr; } else { xbuf[i] = '.'; } if (i % 2) { output_data(" "); } cnt--; ptr++; } xbuf[i] = '\0'; output_data(" %s\r\n", xbuf ); } } #endif /* DIAGNOSTICS */