/* * Copyright (c) 1985, 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. * 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. */ /* * Portions Copyright (c) 1993 by Digital Equipment Corporation. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies, and that * the name of Digital Equipment Corporation not be used in advertising or * publicity pertaining to distribution of the document or software without * specific, written prior permission. * * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS * SOFTWARE. */ /* * Portions Copyright (c) 1996-1999 by Internet Software Consortium. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS * SOFTWARE. */ /* Original copyright ISC as above. * Code modified specifically for ircd use from the following orginal files * in bind ... * * res_comp.c * ns_name.c * ns_netint.c * res_init.c * * - Dianora */ #include "stdinc.h" #include "ircd_defs.h" #include "common.h" #include "ircd.h" #include "res.h" #include "reslib.h" #include "match.h" #include "logger.h" #define NS_TYPE_ELT 0x40 /* EDNS0 extended label type */ #define DNS_LABELTYPE_BITSTRING 0x41 #define DNS_MAXLINE 128 /* $Id: reslib.c 1695 2006-06-27 15:11:23Z jilles $ */ /* from Hybrid Id: reslib.c 177 2005-10-22 09:05:05Z michael $ */ struct rb_sockaddr_storage irc_nsaddr_list[IRCD_MAXNS]; int irc_nscount = 0; char irc_domain[IRCD_RES_HOSTLEN + 1]; static const char digitvalue[256] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/ }; static int parse_resvconf(void); static void add_nameserver(const char *); static const char digits[] = "0123456789"; static int labellen(const unsigned char *lp); static int special(int ch); static int printable(int ch); static int irc_decode_bitstring(const char **cpp, char *dn, const char *eom); static int irc_ns_name_compress(const char *src, unsigned char *dst, size_t dstsiz, const unsigned char **dnptrs, const unsigned char **lastdnptr); static int irc_dn_find(const unsigned char *, const unsigned char *, const unsigned char * const *, const unsigned char * const *); static int irc_encode_bitsring(const char **, const char *, unsigned char **, unsigned char **, const char *); static int irc_ns_name_uncompress(const unsigned char *, const unsigned char *, const unsigned char *, char *, size_t); static int irc_ns_name_unpack(const unsigned char *, const unsigned char *, const unsigned char *, unsigned char *, size_t); static int irc_ns_name_ntop(const char *, char *, size_t); static int irc_ns_name_skip(const unsigned char **, const unsigned char *); static int mklower(int ch); int irc_res_init(void) { irc_nscount = 0; parse_resvconf(); if (irc_nscount == 0) add_nameserver("127.0.0.1"); return 0; } /* parse_resvconf() * * inputs - NONE * output - -1 if failure 0 if success * side effects - fills in irc_nsaddr_list */ static int parse_resvconf(void) { char *p; char *opt; char *arg; char input[DNS_MAXLINE]; FILE *file; /* XXX "/etc/resolv.conf" should be from a define in setup.h perhaps * for cygwin support etc. this hardcodes it to unix for now -db */ if ((file = fopen("/etc/resolv.conf", "r")) == NULL) return -1; while (fgets(input, sizeof(input), file) != NULL) { /* blow away any newline */ if ((p = strpbrk(input, "\r\n")) != NULL) *p = '\0'; p = input; /* skip until something thats not a space is seen */ while (IsSpace(*p)) p++; /* if at this point, have a '\0' then continue */ if (*p == '\0') continue; /* Ignore comment lines immediately */ if (*p == '#' || *p == ';') continue; /* skip until a space is found */ opt = p; while (!IsSpace(*p) && *p != '\0') p++; if (*p == '\0') continue; /* no arguments?.. ignore this line */ /* blow away the space character */ *p++ = '\0'; /* skip these spaces that are before the argument */ while (IsSpace(*p)) p++; /* Now arg should be right where p is pointing */ arg = p; if ((p = strpbrk(arg, " \t")) != NULL) *p = '\0'; /* take the first word */ if (irccmp(opt, "domain") == 0) rb_strlcpy(irc_domain, arg, sizeof(irc_domain)); else if (irccmp(opt, "nameserver") == 0) add_nameserver(arg); } fclose(file); return 0; } /* add_nameserver() * * input - either an IPV4 address in dotted quad * or an IPV6 address in : format * output - NONE * side effects - entry in irc_nsaddr_list is filled in as needed */ static void add_nameserver(const char *arg) { struct addrinfo hints, *res; /* Done max number of nameservers? */ if (irc_nscount >= IRCD_MAXNS) { ilog (L_MAIN, "Too many nameservers, ignoring %s", arg); return; } memset(&hints, 0, sizeof(hints)); hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST; if (getaddrinfo(arg, "domain", &hints, &res)) return; if (res == NULL) return; memcpy(&irc_nsaddr_list[irc_nscount], res->ai_addr, res->ai_addrlen); SET_SS_LEN(&irc_nsaddr_list[irc_nscount], res->ai_addrlen); irc_nscount++; freeaddrinfo(res); } /* * Expand compressed domain name 'comp_dn' to full domain name. * 'msg' is a pointer to the begining of the message, * 'eomorig' points to the first location after the message, * 'exp_dn' is a pointer to a buffer of size 'length' for the result. * Return size of compressed name or -1 if there was an error. */ int irc_dn_expand(const unsigned char *msg, const unsigned char *eom, const unsigned char *src, char *dst, int dstsiz) { int n = irc_ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz); if (n > 0 && dst[0] == '.') dst[0] = '\0'; return(n); } /* * irc_ns_name_uncompress(msg, eom, src, dst, dstsiz) * Expand compressed domain name to presentation format. * return: * Number of bytes read out of `src', or -1 (with errno set). * note: * Root domain returns as "." not "". */ static int irc_ns_name_uncompress(const unsigned char *msg, const unsigned char *eom, const unsigned char *src, char *dst, size_t dstsiz) { unsigned char tmp[NS_MAXCDNAME]; int n; if ((n = irc_ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1) return(-1); if (irc_ns_name_ntop((char*)tmp, dst, dstsiz) == -1) return(-1); return(n); } /* * irc_ns_name_unpack(msg, eom, src, dst, dstsiz) * Unpack a domain name from a message, source may be compressed. * return: * -1 if it fails, or consumed octets if it succeeds. */ static int irc_ns_name_unpack(const unsigned char *msg, const unsigned char *eom, const unsigned char *src, unsigned char *dst, size_t dstsiz) { const unsigned char *srcp, *dstlim; unsigned char *dstp; int n, len, checked, l; len = -1; checked = 0; dstp = dst; srcp = src; dstlim = dst + dstsiz; if (srcp < msg || srcp >= eom) { errno = EMSGSIZE; return (-1); } /* Fetch next label in domain name. */ while ((n = *srcp++) != 0) { /* Check for indirection. */ switch (n & NS_CMPRSFLGS) { case 0: case NS_TYPE_ELT: /* Limit checks. */ if ((l = labellen(srcp - 1)) < 0) { errno = EMSGSIZE; return(-1); } if (dstp + l + 1 >= dstlim || srcp + l >= eom) { errno = EMSGSIZE; return (-1); } checked += l + 1; *dstp++ = n; memcpy(dstp, srcp, l); dstp += l; srcp += l; break; case NS_CMPRSFLGS: if (srcp >= eom) { errno = EMSGSIZE; return (-1); } if (len < 0) len = srcp - src + 1; srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff)); if (srcp < msg || srcp >= eom) { /* Out of range. */ errno = EMSGSIZE; return (-1); } checked += 2; /* * Check for loops in the compressed name; * if we've looked at the whole message, * there must be a loop. */ if (checked >= eom - msg) { errno = EMSGSIZE; return (-1); } break; default: errno = EMSGSIZE; return (-1); /* flag error */ } } *dstp = '\0'; if (len < 0) len = srcp - src; return (len); } /* * irc_ns_name_ntop(src, dst, dstsiz) * Convert an encoded domain name to printable ascii as per RFC1035. * return: * Number of bytes written to buffer, or -1 (with errno set) * notes: * The root is returned as "." * All other domains are returned in non absolute form */ static int irc_ns_name_ntop(const char *src, char *dst, size_t dstsiz) { const char *cp; char *dn, *eom; unsigned char c; unsigned int n; int l; cp = src; dn = dst; eom = dst + dstsiz; while ((n = *cp++) != 0) { if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* Some kind of compression pointer. */ errno = EMSGSIZE; return (-1); } if (dn != dst) { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '.'; } if ((l = labellen((const unsigned char*)(cp - 1))) < 0) { errno = EMSGSIZE; /* XXX */ return(-1); } if (dn + l >= eom) { errno = EMSGSIZE; return (-1); } if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) { int m; if (n != DNS_LABELTYPE_BITSTRING) { /* XXX: labellen should reject this case */ errno = EINVAL; return(-1); } if ((m = irc_decode_bitstring(&cp, dn, eom)) < 0) { errno = EMSGSIZE; return(-1); } dn += m; continue; } for ((void)NULL; l > 0; l--) { c = *cp++; if (special(c)) { if (dn + 1 >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\\'; *dn++ = (char)c; } else if (!printable(c)) { if (dn + 3 >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\\'; *dn++ = digits[c / 100]; *dn++ = digits[(c % 100) / 10]; *dn++ = digits[c % 10]; } else { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = (char)c; } } } if (dn == dst) { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '.'; } if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\0'; return (dn - dst); } /* * Pack domain name 'exp_dn' in presentation form into 'comp_dn'. * Return the size of the compressed name or -1. * 'length' is the size of the array pointed to by 'comp_dn'. */ static int irc_dn_comp(const char *src, unsigned char *dst, int dstsiz, const unsigned char **dnptrs, const unsigned char **lastdnptr) { return(irc_ns_name_compress(src, dst, (size_t)dstsiz, (const unsigned char **)dnptrs, (const unsigned char **)lastdnptr)); } /* * Skip over a compressed domain name. Return the size or -1. */ int irc_dn_skipname(const unsigned char *ptr, const unsigned char *eom) { const unsigned char *saveptr = ptr; if (irc_ns_name_skip(&ptr, eom) == -1) return(-1); return(ptr - saveptr); } /* * ns_name_skip(ptrptr, eom) * Advance *ptrptr to skip over the compressed name it points at. * return: * 0 on success, -1 (with errno set) on failure. */ static int irc_ns_name_skip(const unsigned char **ptrptr, const unsigned char *eom) { const unsigned char *cp; unsigned int n; int l; cp = *ptrptr; while (cp < eom && (n = *cp++) != 0) { /* Check for indirection. */ switch (n & NS_CMPRSFLGS) { case 0: /* normal case, n == len */ cp += n; continue; case NS_TYPE_ELT: /* EDNS0 extended label */ if ((l = labellen(cp - 1)) < 0) { errno = EMSGSIZE; /* XXX */ return(-1); } cp += l; continue; case NS_CMPRSFLGS: /* indirection */ cp++; break; default: /* illegal type */ errno = EMSGSIZE; return(-1); } break; } if (cp > eom) { errno = EMSGSIZE; return (-1); } *ptrptr = cp; return(0); } unsigned int irc_ns_get16(const unsigned char *src) { unsigned int dst; IRC_NS_GET16(dst, src); return(dst); } unsigned long irc_ns_get32(const unsigned char *src) { unsigned long dst; IRC_NS_GET32(dst, src); return(dst); } void irc_ns_put16(unsigned int src, unsigned char *dst) { IRC_NS_PUT16(src, dst); } void irc_ns_put32(unsigned long src, unsigned char *dst) { IRC_NS_PUT32(src, dst); } /* From ns_name.c */ /* * special(ch) * Thinking in noninternationalized USASCII (per the DNS spec), * is this characted special ("in need of quoting") ? * return: * boolean. */ static int special(int ch) { switch (ch) { case 0x22: /* '"' */ case 0x2E: /* '.' */ case 0x3B: /* ';' */ case 0x5C: /* '\\' */ case 0x28: /* '(' */ case 0x29: /* ')' */ /* Special modifiers in zone files. */ case 0x40: /* '@' */ case 0x24: /* '$' */ return(1); default: return(0); } } static int labellen(const unsigned char *lp) { int bitlen; unsigned char l = *lp; if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* should be avoided by the caller */ return(-1); } if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) { if (l == DNS_LABELTYPE_BITSTRING) { if ((bitlen = *(lp + 1)) == 0) bitlen = 256; return((bitlen + 7 ) / 8 + 1); } return(-1); /* unknwon ELT */ } return(l); } /* * printable(ch) * Thinking in noninternationalized USASCII (per the DNS spec), * is this character visible and not a space when printed ? * return: * boolean. */ static int printable(int ch) { return(ch > 0x20 && ch < 0x7f); } static int irc_decode_bitstring(const char **cpp, char *dn, const char *eom) { const char *cp = *cpp; char *beg = dn, tc; int b, blen, plen; if ((blen = (*cp & 0xff)) == 0) blen = 256; plen = (blen + 3) / 4; plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1); if (dn + plen >= eom) return(-1); cp++; dn += sprintf(dn, "\\[x"); for (b = blen; b > 7; b -= 8, cp++) dn += sprintf(dn, "%02x", *cp & 0xff); if (b > 4) { tc = *cp++; dn += sprintf(dn, "%02x", tc & (0xff << (8 - b))); } else if (b > 0) { tc = *cp++; dn += sprintf(dn, "%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b))); } dn += sprintf(dn, "/%d]", blen); *cpp = cp; return(dn - beg); } /* * irc_ns_name_pton(src, dst, dstsiz) * Convert a ascii string into an encoded domain name as per RFC1035. * return: * -1 if it fails * 1 if string was fully qualified * 0 is string was not fully qualified * notes: * Enforces label and domain length limits. */ static int irc_ns_name_pton(const char *src, unsigned char *dst, size_t dstsiz) { unsigned char *label, *bp, *eom; char *cp; int c, n, escaped, e = 0; escaped = 0; bp = dst; eom = dst + dstsiz; label = bp++; while ((c = *src++) != 0) { if (escaped) { if (c == '[') { /* start a bit string label */ if ((cp = strchr(src, ']')) == NULL) { errno = EINVAL; /* ??? */ return(-1); } if ((e = irc_encode_bitsring(&src, cp + 2, &label, &bp, (const char *)eom)) != 0) { errno = e; return(-1); } escaped = 0; label = bp++; if ((c = *src++) == 0) goto done; else if (c != '.') { errno = EINVAL; return(-1); } continue; } else if ((cp = strchr(digits, c)) != NULL) { n = (cp - digits) * 100; if ((c = *src++) == 0 || (cp = strchr(digits, c)) == NULL) { errno = EMSGSIZE; return (-1); } n += (cp - digits) * 10; if ((c = *src++) == 0 || (cp = strchr(digits, c)) == NULL) { errno = EMSGSIZE; return (-1); } n += (cp - digits); if (n > 255) { errno = EMSGSIZE; return (-1); } c = n; } escaped = 0; } else if (c == '\\') { escaped = 1; continue; } else if (c == '.') { c = (bp - label - 1); if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ errno = EMSGSIZE; return (-1); } if (label >= eom) { errno = EMSGSIZE; return (-1); } *label = c; /* Fully qualified ? */ if (*src == '\0') { if (c != 0) { if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = '\0'; } if ((bp - dst) > NS_MAXCDNAME) { errno = EMSGSIZE; return (-1); } return (1); } if (c == 0 || *src == '.') { errno = EMSGSIZE; return (-1); } label = bp++; continue; } if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = (unsigned char)c; } c = (bp - label - 1); if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ errno = EMSGSIZE; return (-1); } done: if (label >= eom) { errno = EMSGSIZE; return (-1); } *label = c; if (c != 0) { if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = 0; } if ((bp - dst) > NS_MAXCDNAME) { /* src too big */ errno = EMSGSIZE; return (-1); } return (0); } /* * irc_ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr) * Pack domain name 'domain' into 'comp_dn'. * return: * Size of the compressed name, or -1. * notes: * 'dnptrs' is an array of pointers to previous compressed names. * dnptrs[0] is a pointer to the beginning of the message. The array * ends with NULL. * 'lastdnptr' is a pointer to the end of the array pointed to * by 'dnptrs'. * Side effects: * The list of pointers in dnptrs is updated for labels inserted into * the message as we compress the name. If 'dnptr' is NULL, we don't * try to compress names. If 'lastdnptr' is NULL, we don't update the * list. */ static int irc_ns_name_pack(const unsigned char *src, unsigned char *dst, int dstsiz, const unsigned char **dnptrs, const unsigned char **lastdnptr) { unsigned char *dstp; const unsigned char **cpp, **lpp, *eob, *msg; const unsigned char *srcp; int n, l, first = 1; srcp = src; dstp = dst; eob = dstp + dstsiz; lpp = cpp = NULL; if (dnptrs != NULL) { if ((msg = *dnptrs++) != NULL) { for (cpp = dnptrs; *cpp != NULL; cpp++) (void)NULL; lpp = cpp; /* end of list to search */ } } else msg = NULL; /* make sure the domain we are about to add is legal */ l = 0; do { int l0; n = *srcp; if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { errno = EMSGSIZE; return (-1); } if ((l0 = labellen(srcp)) < 0) { errno = EINVAL; return(-1); } l += l0 + 1; if (l > NS_MAXCDNAME) { errno = EMSGSIZE; return (-1); } srcp += l0 + 1; } while (n != 0); /* from here on we need to reset compression pointer array on error */ srcp = src; do { /* Look to see if we can use pointers. */ n = *srcp; if (n != 0 && msg != NULL) { l = irc_dn_find(srcp, msg, (const unsigned char * const *)dnptrs, (const unsigned char * const *)lpp); if (l >= 0) { if (dstp + 1 >= eob) { goto cleanup; } *dstp++ = (l >> 8) | NS_CMPRSFLGS; *dstp++ = l % 256; return (dstp - dst); } /* Not found, save it. */ if (lastdnptr != NULL && cpp < lastdnptr - 1 && (dstp - msg) < 0x4000 && first) { *cpp++ = dstp; *cpp = NULL; first = 0; } } /* copy label to buffer */ if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* Should not happen. */ goto cleanup; } n = labellen(srcp); if (dstp + 1 + n >= eob) { goto cleanup; } memcpy(dstp, srcp, n + 1); srcp += n + 1; dstp += n + 1; } while (n != 0); if (dstp > eob) { cleanup: if (msg != NULL) *lpp = NULL; errno = EMSGSIZE; return (-1); } return(dstp - dst); } static int irc_ns_name_compress(const char *src, unsigned char *dst, size_t dstsiz, const unsigned char **dnptrs, const unsigned char **lastdnptr) { unsigned char tmp[NS_MAXCDNAME]; if (irc_ns_name_pton(src, tmp, sizeof tmp) == -1) return(-1); return(irc_ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr)); } static int irc_encode_bitsring(const char **bp, const char *end, unsigned char **labelp, unsigned char **dst, const char *eom) { int afterslash = 0; const char *cp = *bp; char *tp, c; const char *beg_blen; char *end_blen = NULL; int value = 0, count = 0, tbcount = 0, blen = 0; beg_blen = end_blen = NULL; /* a bitstring must contain at least 2 characters */ if (end - cp < 2) return(EINVAL); /* XXX: currently, only hex strings are supported */ if (*cp++ != 'x') return(EINVAL); if (!isxdigit((*cp) & 0xff)) /* reject '\[x/BLEN]' */ return(EINVAL); for (tp = (char*)(dst + 1); cp < end && tp < eom; cp++) { switch((c = *cp)) { case ']': /* end of the bitstring */ if (afterslash) { if (beg_blen == NULL) return(EINVAL); blen = (int)strtol(beg_blen, &end_blen, 10); if (*end_blen != ']') return(EINVAL); } if (count) *tp++ = ((value << 4) & 0xff); cp++; /* skip ']' */ goto done; case '/': afterslash = 1; break; default: if (afterslash) { if (!isdigit(c&0xff)) return(EINVAL); if (beg_blen == NULL) { if (c == '0') { /* blen never begings with 0 */ return(EINVAL); } beg_blen = cp; } } else { if (!isxdigit(c&0xff)) return(EINVAL); value <<= 4; value += digitvalue[(int)c]; count += 4; tbcount += 4; if (tbcount > 256) return(EINVAL); if (count == 8) { *tp++ = value; count = 0; } } break; } } done: if (cp >= end || tp >= eom) return(EMSGSIZE); /* * bit length validation: * If a is present, the number of digits in the * MUST be just sufficient to contain the number of bits specified * by the . If there are insignificant bits in a final * hexadecimal or octal digit, they MUST be zero. * RFC 2673, Section 3.2. */ if (blen > 0) { int traillen; if (((blen + 3) & ~3) != tbcount) return(EINVAL); traillen = tbcount - blen; /* between 0 and 3 */ if (((value << (8 - traillen)) & 0xff) != 0) return(EINVAL); } else blen = tbcount; if (blen == 256) blen = 0; /* encode the type and the significant bit fields */ **labelp = DNS_LABELTYPE_BITSTRING; **dst = blen; *bp = cp; *dst = (unsigned char*)tp; return(0); } /* * dn_find(domain, msg, dnptrs, lastdnptr) * Search for the counted-label name in an array of compressed names. * return: * offset from msg if found, or -1. * notes: * dnptrs is the pointer to the first name on the list, * not the pointer to the start of the message. */ static int irc_dn_find(const unsigned char *domain, const unsigned char *msg, const unsigned char * const *dnptrs, const unsigned char * const *lastdnptr) { const unsigned char *dn, *cp, *sp; const unsigned char * const *cpp; unsigned int n; for (cpp = dnptrs; cpp < lastdnptr; cpp++) { sp = *cpp; /* * terminate search on: * root label * compression pointer * unusable offset */ while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 && (sp - msg) < 0x4000) { dn = domain; cp = sp; while ((n = *cp++) != 0) { /* * check for indirection */ switch (n & NS_CMPRSFLGS) { case 0: /* normal case, n == len */ n = labellen(cp - 1); /* XXX */ if (n != *dn++) goto next; for ((void)NULL; n > 0; n--) if (mklower(*dn++) != mklower(*cp++)) goto next; /* Is next root for both ? */ if (*dn == '\0' && *cp == '\0') return (sp - msg); if (*dn) continue; goto next; case NS_CMPRSFLGS: /* indirection */ cp = msg + (((n & 0x3f) << 8) | *cp); break; default: /* illegal type */ errno = EMSGSIZE; return (-1); } } next: ; sp += *sp + 1; } } errno = ENOENT; return (-1); } /* * * Thinking in noninternationalized USASCII (per the DNS spec), * * convert this character to lower case if it's upper case. * */ static int mklower(int ch) { if (ch >= 0x41 && ch <= 0x5A) return(ch + 0x20); return(ch); } /* From resolv/mkquery.c */ /* * Form all types of queries. * Returns the size of the result or -1. */ int irc_res_mkquery( const char *dname, /* domain name */ int class, int type, /* class and type of query */ unsigned char *buf, /* buffer to put query */ int buflen) /* size of buffer */ { HEADER *hp; unsigned char *cp; int n; const unsigned char *dnptrs[20], **dpp, **lastdnptr; /* * Initialize header fields. */ if ((buf == NULL) || (buflen < HFIXEDSZ)) return (-1); memset(buf, 0, HFIXEDSZ); hp = (HEADER *)(void *)buf; hp->id = 0; hp->opcode = QUERY; hp->rd = 1; /* recurse */ hp->rcode = NO_ERRORS; cp = buf + HFIXEDSZ; buflen -= HFIXEDSZ; dpp = dnptrs; *dpp++ = buf; *dpp++ = NULL; lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0]; if ((buflen -= QFIXEDSZ) < 0) return (-1); if ((n = irc_dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0) return (-1); cp += n; buflen -= n; IRC_NS_PUT16(type, cp); IRC_NS_PUT16(class, cp); hp->qdcount = htons(1); return (cp - buf); }