dnsapi: Add DNS message parsing routines from BIND.
diff --git a/dlls/dnsapi/Makefile.in b/dlls/dnsapi/Makefile.in
index 1ff2025..2575b86 100644
--- a/dlls/dnsapi/Makefile.in
+++ b/dlls/dnsapi/Makefile.in
@@ -10,6 +10,8 @@
C_SRCS = \
main.c \
name.c \
+ ns_name.c \
+ ns_parse.c \
query.c \
record.c
diff --git a/dlls/dnsapi/dnsapi.h b/dlls/dnsapi/dnsapi.h
index 8e96f77..915b3a0 100644
--- a/dlls/dnsapi/dnsapi.h
+++ b/dlls/dnsapi/dnsapi.h
@@ -137,3 +137,8 @@
}
return dst;
}
+
+int dns_ns_initparse( const u_char *, int, ns_msg * );
+int dns_ns_parserr( ns_msg *, ns_sect, int, ns_rr * );
+int dns_ns_name_skip( const u_char **, const u_char * );
+int dns_ns_name_uncompress( const u_char *, const u_char *, const u_char *, char *, size_t );
diff --git a/dlls/dnsapi/ns_name.c b/dlls/dnsapi/ns_name.c
new file mode 100644
index 0000000..0c7c24d
--- /dev/null
+++ b/dlls/dnsapi/ns_name.c
@@ -0,0 +1,708 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+
+#include <sys/types.h>
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+# include <arpa/nameser.h>
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#ifdef HAVE_RESOLV_H
+# include <resolv.h>
+#endif
+#include <string.h>
+#include <ctype.h>
+
+/* Data. */
+
+static const char digits[] = "0123456789";
+
+/* Forward. */
+
+static int special(int);
+static int printable(int);
+static int dn_find(const u_char *, const u_char *,
+ const u_char * const *,
+ const u_char * const *);
+
+/* Public. */
+
+/*
+ * dns_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
+ */
+int
+dns_ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) {
+ const u_char *cp;
+ char *dn, *eom;
+ u_char c;
+ u_int n;
+
+ cp = src;
+ dn = dst;
+ eom = dst + dstsiz;
+
+ while ((n = *cp++) != 0) {
+ if ((n & NS_CMPRSFLGS) != 0 && n != 0x41) {
+ /* Some kind of compression pointer. */
+ return (-1);
+ }
+ if (dn != dst) {
+ if (dn >= eom) {
+ return (-1);
+ }
+ *dn++ = '.';
+ }
+
+ if (n == 0x41) {
+ n = *cp++ / 8;
+ if (dn + n * 2 + 4 >= eom) {
+ return (-1);
+ }
+ *dn++ = '\\';
+ *dn++ = '[';
+ *dn++ = 'x';
+
+ while (n-- > 0) {
+ unsigned u;
+ c = *cp++;
+ u = c >> 4;
+ *dn++ = u > 9 ? 'a' + u - 10 : '0' + u;
+ u = c & 0xf;
+ *dn++ = u > 9 ? 'a' + u - 10 : '0' + u;
+ }
+
+ *dn++ = ']';
+ continue;
+ }
+
+ if (dn + n >= eom) {
+ return (-1);
+ }
+ for ((void)NULL; n > 0; n--) {
+ c = *cp++;
+ if (special(c)) {
+ if (dn + 1 >= eom) {
+ return (-1);
+ }
+ *dn++ = '\\';
+ *dn++ = (char)c;
+ } else if (!printable(c)) {
+ if (dn + 3 >= eom) {
+ return (-1);
+ }
+ *dn++ = '\\';
+ *dn++ = digits[c / 100];
+ *dn++ = digits[(c % 100) / 10];
+ *dn++ = digits[c % 10];
+ } else {
+ if (dn >= eom) {
+ return (-1);
+ }
+ *dn++ = (char)c;
+ }
+ }
+ }
+ if (dn == dst) {
+ if (dn >= eom) {
+ return (-1);
+ }
+ *dn++ = '.';
+ }
+ if (dn >= eom) {
+ return (-1);
+ }
+ *dn++ = '\0';
+ return (dn - dst);
+}
+
+/*
+ * dns_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.
+ */
+
+int
+dns_ns_name_pton(const char *src, u_char *dst, size_t dstsiz) {
+ u_char *label, *bp, *eom;
+ int c, n, escaped;
+ char *cp;
+
+ escaped = 0;
+ bp = dst;
+ eom = dst + dstsiz;
+ label = bp++;
+
+ while ((c = *src++) != 0) {
+ if (escaped) {
+ if ((cp = strchr(digits, c)) != NULL) {
+ n = (cp - digits) * 100;
+ if ((c = *src++) == 0 ||
+ (cp = strchr(digits, c)) == NULL) {
+ return (-1);
+ }
+ n += (cp - digits) * 10;
+ if ((c = *src++) == 0 ||
+ (cp = strchr(digits, c)) == NULL) {
+ return (-1);
+ }
+ n += (cp - digits);
+ if (n > 255) {
+ return (-1);
+ }
+ c = n;
+ } else if (c == '[' && label == bp - 1 && *src == 'x') {
+ /* Theoretically we would have to handle \[o
+ as well but we do not since we do not need
+ it internally. */
+ *label = 0x41;
+ label = bp++;
+ ++src;
+ while (isxdigit (*src)) {
+ n = *src > '9' ? *src - 'a' + 10 : *src - '0';
+ ++src;
+ if (! isxdigit(*src)) {
+ return (-1);
+ }
+ n <<= 4;
+ n += *src > '9' ? *src - 'a' + 10 : *src - '0';
+ if (bp + 1 >= eom) {
+ return (-1);
+ }
+ *bp++ = n;
+ ++src;
+ }
+ *label = (bp - label - 1) * 8;
+ if (*src++ != ']' || *src++ != '.') {
+ return (-1);
+ }
+ escaped = 0;
+ label = bp++;
+ if (bp >= eom) {
+ return (-1);
+ }
+ continue;
+ }
+ escaped = 0;
+ } else if (c == '\\') {
+ escaped = 1;
+ continue;
+ } else if (c == '.') {
+ c = (bp - label - 1);
+ if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
+ return (-1);
+ }
+ if (label >= eom) {
+ return (-1);
+ }
+ *label = c;
+ /* Fully qualified ? */
+ if (*src == '\0') {
+ if (c != 0) {
+ if (bp >= eom) {
+ return (-1);
+ }
+ *bp++ = '\0';
+ }
+ if ((bp - dst) > MAXCDNAME) {
+ return (-1);
+ }
+ return (1);
+ }
+ if (c == 0 || *src == '.') {
+ return (-1);
+ }
+ label = bp++;
+ continue;
+ }
+ if (bp >= eom) {
+ return (-1);
+ }
+ *bp++ = (u_char)c;
+ }
+ c = (bp - label - 1);
+ if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
+ return (-1);
+ }
+ if (label >= eom) {
+ return (-1);
+ }
+ *label = c;
+ if (c != 0) {
+ if (bp >= eom) {
+ return (-1);
+ }
+ *bp++ = 0;
+ }
+ if ((bp - dst) > MAXCDNAME) { /* src too big */
+ return (-1);
+ }
+ return (0);
+}
+
+/*
+ * ns_name_ntol(src, dst, dstsiz)
+ * Convert a network strings labels into all lowercase.
+ * return:
+ * Number of bytes written to buffer, or -1 (with errno set)
+ * notes:
+ * Enforces label and domain length limits.
+ */
+
+int
+ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) {
+ const u_char *cp;
+ u_char *dn, *eom;
+ u_char c;
+ u_int n;
+
+ cp = src;
+ dn = dst;
+ eom = dst + dstsiz;
+
+ while ((n = *cp++) != 0) {
+ if ((n & NS_CMPRSFLGS) != 0) {
+ /* Some kind of compression pointer. */
+ return (-1);
+ }
+ *dn++ = n;
+ if (dn + n >= eom) {
+ return (-1);
+ }
+ for ((void)NULL; n > 0; n--) {
+ c = *cp++;
+ if (isupper(c))
+ *dn++ = tolower(c);
+ else
+ *dn++ = c;
+ }
+ }
+ *dn++ = '\0';
+ return (dn - dst);
+}
+
+/*
+ * dns_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.
+ */
+int
+dns_ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
+ u_char *dst, size_t dstsiz)
+{
+ const u_char *srcp, *dstlim;
+ u_char *dstp;
+ int n, len, checked;
+
+ len = -1;
+ checked = 0;
+ dstp = dst;
+ srcp = src;
+ dstlim = dst + dstsiz;
+ if (srcp < msg || srcp >= eom) {
+ return (-1);
+ }
+ /* Fetch next label in domain name. */
+ while ((n = *srcp++) != 0) {
+ /* Check for indirection. */
+ switch (n & NS_CMPRSFLGS) {
+ case 0x40:
+ if (n == 0x41) {
+ if (dstp + 1 >= dstlim) {
+ return (-1);
+ }
+ *dstp++ = 0x41;
+ n = *srcp++ / 8;
+ ++checked;
+ } else {
+ return (-1); /* flag error */
+ }
+ /* FALLTHROUGH */
+ case 0:
+ /* Limit checks. */
+ if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
+ return (-1);
+ }
+ checked += n + 1;
+ dstp = memcpy(dstp, srcp - 1, n + 1);
+ dstp += n + 1;
+ srcp += n;
+ break;
+
+ case NS_CMPRSFLGS:
+ if (srcp >= eom) {
+ return (-1);
+ }
+ if (len < 0)
+ len = srcp - src + 1;
+ srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
+ if (srcp < msg || srcp >= eom) { /* Out of range. */
+ 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) {
+ return (-1);
+ }
+ break;
+
+ default:
+ return (-1); /* flag error */
+ }
+ }
+ *dstp = '\0';
+ if (len < 0)
+ len = srcp - src;
+ return (len);
+}
+
+/*
+ * 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.
+ */
+int
+ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
+ const u_char **dnptrs, const u_char **lastdnptr)
+{
+ u_char *dstp;
+ const u_char **cpp, **lpp, *eob, *msg;
+ const u_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 {
+ n = *srcp;
+ if ((n & NS_CMPRSFLGS) != 0 && n != 0x41) {
+ return (-1);
+ }
+ if (n == 0x41)
+ n = *++srcp / 8;
+ l += n + 1;
+ if (l > MAXCDNAME) {
+ return (-1);
+ }
+ srcp += n + 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 && n != 0x41 && msg != NULL) {
+ l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
+ (const u_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) != 0 && n != 0x41) { /* Should not happen. */
+ goto cleanup;
+ }
+ if (n == 0x41) {
+ n = *++srcp / 8;
+ if (dstp + 1 >= eob)
+ goto cleanup;
+ *dstp++ = 0x41;
+ }
+ 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;
+ return (-1);
+ }
+ return (dstp - dst);
+}
+
+/*
+ * dns_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 "".
+ */
+int
+dns_ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
+ char *dst, size_t dstsiz)
+{
+ u_char tmp[NS_MAXCDNAME];
+ int n;
+
+ if ((n = dns_ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
+ return (-1);
+ if (dns_ns_name_ntop(tmp, dst, dstsiz) == -1)
+ return (-1);
+ return (n);
+}
+
+/*
+ * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
+ * Compress a domain name into wire format, using compression pointers.
+ * return:
+ * Number of bytes consumed in `dst' or -1 (with errno set).
+ * notes:
+ * 'dnptrs' is an array of pointers to previous compressed names.
+ * dnptrs[0] is a pointer to the beginning of the message.
+ * The list ends with NULL. 'lastdnptr' is a pointer to the end of the
+ * array pointed to by 'dnptrs'. Side effect is to update the list of
+ * pointers 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.
+ */
+int
+ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
+ const u_char **dnptrs, const u_char **lastdnptr)
+{
+ u_char tmp[NS_MAXCDNAME];
+
+ if (dns_ns_name_pton(src, tmp, sizeof tmp) == -1)
+ return (-1);
+ return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
+}
+
+/*
+ * Reset dnptrs so that there are no active references to pointers at or
+ * after src.
+ */
+void
+ns_name_rollback(const u_char *src, const u_char **dnptrs,
+ const u_char **lastdnptr)
+{
+ while (dnptrs < lastdnptr && *dnptrs != NULL) {
+ if (*dnptrs >= src) {
+ *dnptrs = NULL;
+ break;
+ }
+ dnptrs++;
+ }
+}
+
+/*
+ * dns_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.
+ */
+int
+dns_ns_name_skip(const u_char **ptrptr, const u_char *eom) {
+ const u_char *cp;
+ u_int n;
+
+ 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_CMPRSFLGS: /* indirection */
+ cp++;
+ break;
+ default: /* illegal type */
+ return (-1);
+ }
+ break;
+ }
+ if (cp > eom) {
+ return (-1);
+ }
+ *ptrptr = cp;
+ return (0);
+}
+
+/* Private. */
+
+/*
+ * 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: /* '\\' */
+ /* Special modifiers in zone files. */
+ case 0x40: /* '@' */
+ case 0x24: /* '$' */
+ return (1);
+ default:
+ return (0);
+ }
+}
+
+/*
+ * 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);
+}
+
+/*
+ * 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);
+}
+
+/*
+ * 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
+dn_find(const u_char *domain, const u_char *msg,
+ const u_char * const *dnptrs,
+ const u_char * const *lastdnptr)
+{
+ const u_char *dn, *cp, *sp;
+ const u_char * const *cpp;
+ u_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 */
+ 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 */
+ return (-1);
+ }
+ }
+ next:
+ sp += *sp + 1;
+ }
+ }
+ return (-1);
+}
diff --git a/dlls/dnsapi/ns_parse.c b/dlls/dnsapi/ns_parse.c
new file mode 100644
index 0000000..e9a15ac
--- /dev/null
+++ b/dlls/dnsapi/ns_parse.c
@@ -0,0 +1,196 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+
+#include <sys/types.h>
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+# include <arpa/nameser.h>
+#endif
+
+#include <errno.h>
+#ifdef HAVE_RESOLV_H
+# include <resolv.h>
+#endif
+#include <string.h>
+
+/* Forward. */
+
+static void setsection(ns_msg *msg, ns_sect sect);
+
+/* Macros. */
+
+#define RETERR(err) do { return (-1); } while (0)
+
+/* Public. */
+
+/* These need to be in the same order as the nres.h:ns_flag enum. */
+struct _ns_flagdata _ns_flagdata[16] = {
+ { 0x8000, 15 }, /* qr. */
+ { 0x7800, 11 }, /* opcode. */
+ { 0x0400, 10 }, /* aa. */
+ { 0x0200, 9 }, /* tc. */
+ { 0x0100, 8 }, /* rd. */
+ { 0x0080, 7 }, /* ra. */
+ { 0x0040, 6 }, /* z. */
+ { 0x0020, 5 }, /* ad. */
+ { 0x0010, 4 }, /* cd. */
+ { 0x000f, 0 }, /* rcode. */
+ { 0x0000, 0 }, /* expansion (1/6). */
+ { 0x0000, 0 }, /* expansion (2/6). */
+ { 0x0000, 0 }, /* expansion (3/6). */
+ { 0x0000, 0 }, /* expansion (4/6). */
+ { 0x0000, 0 }, /* expansion (5/6). */
+ { 0x0000, 0 }, /* expansion (6/6). */
+};
+
+int
+ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
+ const u_char *optr = ptr;
+
+ for ((void)NULL; count > 0; count--) {
+ int b, rdlength;
+
+ b = dn_skipname(ptr, eom);
+ if (b < 0)
+ RETERR(EMSGSIZE);
+ ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
+ if (section != ns_s_qd) {
+ if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
+ RETERR(EMSGSIZE);
+ ptr += NS_INT32SZ/*TTL*/;
+ NS_GET16(rdlength, ptr);
+ ptr += rdlength/*RData*/;
+ }
+ }
+ if (ptr > eom)
+ RETERR(EMSGSIZE);
+ return (ptr - optr);
+}
+
+int
+dns_ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
+ const u_char *eom = msg + msglen;
+ int i;
+
+ memset(handle, 0x5e, sizeof *handle);
+ handle->_msg = msg;
+ handle->_eom = eom;
+ if (msg + NS_INT16SZ > eom)
+ RETERR(EMSGSIZE);
+ NS_GET16(handle->_id, msg);
+ if (msg + NS_INT16SZ > eom)
+ RETERR(EMSGSIZE);
+ NS_GET16(handle->_flags, msg);
+ for (i = 0; i < ns_s_max; i++) {
+ if (msg + NS_INT16SZ > eom)
+ RETERR(EMSGSIZE);
+ NS_GET16(handle->_counts[i], msg);
+ }
+ for (i = 0; i < ns_s_max; i++)
+ if (handle->_counts[i] == 0)
+ handle->_sections[i] = NULL;
+ else {
+ int b = ns_skiprr(msg, eom, (ns_sect)i,
+ handle->_counts[i]);
+
+ if (b < 0)
+ return (-1);
+ handle->_sections[i] = msg;
+ msg += b;
+ }
+ if (msg != eom)
+ RETERR(EMSGSIZE);
+ setsection(handle, ns_s_max);
+ return (0);
+}
+
+int
+dns_ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
+ int b;
+
+ /* Make section right. */
+ if (section < 0 || section >= ns_s_max)
+ RETERR(ENODEV);
+ if (section != handle->_sect)
+ setsection(handle, section);
+
+ /* Make rrnum right. */
+ if (rrnum == -1)
+ rrnum = handle->_rrnum;
+ if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
+ RETERR(ENODEV);
+ if (rrnum < handle->_rrnum)
+ setsection(handle, section);
+ if (rrnum > handle->_rrnum) {
+ b = ns_skiprr(handle->_ptr, handle->_eom, section,
+ rrnum - handle->_rrnum);
+
+ if (b < 0)
+ return (-1);
+ handle->_ptr += b;
+ handle->_rrnum = rrnum;
+ }
+
+ /* Do the parse. */
+ b = dn_expand(handle->_msg, handle->_eom,
+ handle->_ptr, rr->name, NS_MAXDNAME);
+ if (b < 0)
+ return (-1);
+ handle->_ptr += b;
+ if (handle->_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
+ RETERR(EMSGSIZE);
+ NS_GET16(rr->type, handle->_ptr);
+ NS_GET16(rr->rr_class, handle->_ptr);
+ if (section == ns_s_qd) {
+ rr->ttl = 0;
+ rr->rdlength = 0;
+ rr->rdata = NULL;
+ } else {
+ if (handle->_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
+ RETERR(EMSGSIZE);
+ NS_GET32(rr->ttl, handle->_ptr);
+ NS_GET16(rr->rdlength, handle->_ptr);
+ if (handle->_ptr + rr->rdlength > handle->_eom)
+ RETERR(EMSGSIZE);
+ rr->rdata = handle->_ptr;
+ handle->_ptr += rr->rdlength;
+ }
+ if (++handle->_rrnum > handle->_counts[(int)section])
+ setsection(handle, (ns_sect)((int)section + 1));
+
+ /* All done. */
+ return (0);
+}
+
+/* Private. */
+
+static void
+setsection(ns_msg *msg, ns_sect sect) {
+ msg->_sect = sect;
+ if (sect == ns_s_max) {
+ msg->_rrnum = -1;
+ msg->_ptr = NULL;
+ } else {
+ msg->_rrnum = 0;
+ msg->_ptr = msg->_sections[(int)sect];
+ }
+}
