--- /dev/null
+/*
+ * 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.
+ * 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.
+ */
+
+/*
+ * 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 original files
+ * in bind ...
+ *
+ * res_comp.c
+ * ns_name.c
+ * ns_netint.c
+ * res_init.c
+ *
+ * - Dianora
+ */
+
+#include "ircd.h"
+#include "res.h"
+#include "ircd_reslib.h"
+#include "ircd_defs.h"
+#include "fileio.h"
+#include "ircd_string.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define NS_TYPE_ELT 0x40 /**< EDNS0 extended label type */
+#define DNS_LABELTYPE_BITSTRING 0x41 /**< Bitstring label */
+#define MAXLINE 128 /**< Maximum line length for resolv.conf */
+
+/** @file
+ * @brief DNS resolver library functions.
+ * @version $Id$
+ */
+
+/** Array of nameserver addresses. */
+struct irc_sockaddr irc_nsaddr_list[IRCD_MAXNS];
+/** Number of nameservers in #irc_nsaddr_list. */
+int irc_nscount;
+/** Local domain to use as a search suffix. */
+char irc_domain[HOSTLEN + 1];
+
+/** Maps hex digits to their values, or -1 for other characters. */
+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);
+
+/** Array of decimal digits, indexed by value. */
+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 mklower(int ch);
+
+/** Initialize the resolver library.
+ * @return Zero on success, non-zero on failure.
+ */
+int
+irc_res_init(void)
+{
+ return (irc_nscount == 0) ? parse_resvconf() : 0;
+}
+
+/** Read resolver configuration file for domain and nameserver lines.
+ * The "domain" line is used to overwrite #irc_domain.
+ * Addresses in "nameserver" lines are appended to #irc_nsaddr_list.
+ * @return Zero on success, non-zero on failure.
+ */
+static int
+parse_resvconf(void)
+{
+ char *p;
+ char *opt;
+ char *arg;
+ char input[MAXLINE];
+ FBFILE *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 = fbopen("/etc/resolv.conf", "r")) == NULL)
+ return(-1);
+
+ while (fbgets(input, MAXLINE, file) != NULL)
+ {
+ /* blow away any newline */
+ if ((p = strpbrk(input, "\r\n")) != NULL)
+ *p = '\0';
+
+ /* Ignore comment lines immediately */
+ if (*input == '#')
+ continue;
+
+ p = input;
+ /* skip until something that's not a space is seen */
+ while (IsSpace(*p))
+ p++;
+ /* if at this point, have a '\0' then continue */
+ if (*p == '\0')
+ continue;
+
+ /* skip until a space is found */
+ opt = input;
+ while (!IsSpace(*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 (strcasecmp(opt, "domain") == 0)
+ ircd_strncpy(irc_domain, arg, HOSTLEN);
+ else if (strcasecmp(opt, "nameserver") == 0)
+ add_nameserver(arg);
+ }
+
+ fbclose(file);
+ return(0);
+}
+
+/** Add a resolver to #irc_nsaddr_list.
+ * @param[in] arg Dotted quad or IPv6 text form of nameserver address.
+ */
+void
+add_nameserver(const char *arg)
+{
+ struct irc_sockaddr res;
+
+ /* Done max number of nameservers? */
+ if (irc_nscount >= IRCD_MAXNS)
+ return;
+
+ /* Failure converting from numeric string? */
+ if (!ircd_aton(&res.addr, arg))
+ return;
+ res.port = 53;
+ memcpy(&irc_nsaddr_list[irc_nscount], &res, sizeof(irc_nsaddr_list[irc_nscount]));
+ irc_nscount++;
+}
+
+/**
+ * Expand compressed domain name to full domain name.
+ * Like irc_ns_name_uncompress(), but checks for a well-formed result.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
+ */
+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);
+}
+
+/**
+ * Expand compressed domain name to full domain name.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
+ */
+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, (char*)dst, dstsiz) == -1)
+ return(-1);
+ return(n);
+}
+
+/**
+ * Unpack compressed domain name to uncompressed form.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
+ */
+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);
+}
+
+/**
+ * Convert RFC1035 length-prefixed tag sequence to printable ASCII.
+ * @param[in] src Input tag sequence (effectively NUL terminated).
+ * @param[out] dst Buffer for uncompressed output.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
+ */
+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 from presentation form into compressed format.
+ * @param[in] src Presentation form of name.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in,out] dnptrs Array of previously seen labels.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ * @return Number of bytes written to \a dst.
+ */
+int
+irc_dn_comp(const char *src, unsigned char *dst, int dstsiz,
+ unsigned char **dnptrs, 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.
+ * @param[in] ptr Start of compressed name.
+ * @param[in] eom End of message.
+ * @return Length of the compressed name, or -1 on error.
+ */
+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);
+}
+
+/** Advance \a ptrptr to skip over the compressed name it points at.
+ * @param[in,out] ptrptr Pointer to the compressed name.
+ * @param[in] eom End of message.
+ * @return Zero on success; non-zero (with errno set) on failure.
+ */
+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);
+}
+
+/** Read a 16-bit network-endian value from \a src.
+ * @param[in] src Input data buffer.
+ * @return Value retrieved from buffer.
+ */
+unsigned int
+irc_ns_get16(const unsigned char *src)
+{
+ unsigned int dst;
+
+ IRC_NS_GET16(dst, src);
+ return(dst);
+}
+
+/** Read a 32-bit network-endian value from \a src.
+ * @param[in] src Input data buffer.
+ * @return Value retrieved from buffer.
+ */
+unsigned long
+irc_ns_get32(const unsigned char *src)
+{
+ unsigned long dst;
+
+ IRC_NS_GET32(dst, src);
+ return(dst);
+}
+
+/** Write a 16-bit network-endian value to \a dst.
+ * @param[in] src Value to write.
+ * @param[out] dst Output buffer.
+ */
+void
+irc_ns_put16(unsigned int src, unsigned char *dst)
+{
+ IRC_NS_PUT16(src, dst);
+}
+
+/** Write a 32-bit network-endian value to \a dst.
+ * @param[in] src Value to write.
+ * @param[out] dst Output buffer.
+ */
+void
+irc_ns_put32(unsigned long src, unsigned char *dst)
+{
+ IRC_NS_PUT32(src, dst);
+}
+
+/* From ns_name.c */
+
+/** Indicate whether a character needs quoting.
+ * (What RFC does this come from?)
+ * @param[in] ch Character to check for specialness.
+ * @return Non-zero if the character should be quoted.
+ */
+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);
+ }
+}
+
+/** Calculate the length of a particular DNS label.
+ * @param[in] lp Start of label.
+ * @return Length of label, or -1 on error.
+ */
+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); /* unknown ELT */
+ }
+
+ return(l);
+}
+
+
+/** Indicate whether a character is printable.
+ * @param[in] ch Character to check for printability.
+ * @return Non-zero if the character is printable; zero if it is not.
+ */
+static int
+printable(int ch)
+{
+ return(ch > 0x20 && ch < 0x7f);
+}
+
+/** Decode a bitstring label from DNS.
+ * @param[in,out] cpp Pointer to start of label.
+ * @param[in,out] dn Output buffer.
+ * @param[in] eom End of message.
+ */
+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);
+}
+
+/** Convert an ASCII name string into an encoded domain name.
+ * This function enforces per-label and total name lengths.
+ * @param[in] src ASCII name string.
+ * @param[out] dst Destination buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return -1 on failure, 0 if \a src was not fully qualified, 1 if \a
+ * src was fully qualified.
+ */
+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);
+}
+
+/** Compress a domain name.
+ * @param[in] src List of length-prefixed labels.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in,out] dnptrs Array of pointers to previously compressed names.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ * @return Number of bytes written to \a dst.
+ */
+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);
+}
+
+/** Encode and compress an ASCII domain name.
+ * @param[in] src ASCII domain name.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in] dnptrs Array of previously compressed names.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ */
+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));
+}
+
+/** Encode a bitstring label.
+ * @param[in,out] bp Input buffer pointer.
+ * @param[in] end End of input buffer.
+ * @param[out] labelp Pointer to output label.
+ * @param[out] dst Output buffer.
+ * @param[out] eom End of output buffer.
+ */
+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 begins 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 <length> is present, the number of digits in the <bit-data>
+ * MUST be just sufficient to contain the number of bits specified
+ * by the <length>. 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);
+}
+
+/** Find a name in an array of compressed name.
+ * @param[in] domain Name to search for.
+ * @param[in] msg Start of DNS message.
+ * @param[in] dnptrs Start of compressed name array.
+ * @param[in] lastdnptr End of compressed name array.
+ * @return Non-negative offset from \a msg, or -1 if not found.
+ */
+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);
+}
+
+/** Convert a character to lowercase, assuming ASCII encoded English.
+ * @param[in] ch Character to convert.
+ * @return Lower-case version of \a ch.
+ */
+static int
+mklower(int ch)
+{
+ if (ch >= 0x41 && ch <= 0x5A)
+ return(ch + 0x20);
+
+ return(ch);
+}
+
+/* From resolv/mkquery.c */
+
+/** Form a query for \a dname in \a buf.
+ * @param[in] dname Domain name to look up.
+ * @param[in] class Query class to set in header.
+ * @param[in] type Query type to set in header.
+ * @param[out] buf Output buffer for query.
+ * @param[in] buflen Number of bytes that can be written to \a buf.
+ * @return Length of message written to \a buf, or -1 on error.
+ */
+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;
+ unsigned char *dnptrs[20], **dpp, **lastdnptr;
+
+ /*
+ * Initialize header fields.
+ */
+ if ((buf == NULL) || (buflen < HFIXEDSZ))
+ return (-1);
+ memset(buf, 0, HFIXEDSZ);
+ hp = (HEADER *) 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);
+}
projects / ircu2.10.12-pk.git / blobdiff