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-rw-r--r--resolv/ns_name.c636
1 files changed, 636 insertions, 0 deletions
diff --git a/resolv/ns_name.c b/resolv/ns_name.c
new file mode 100644
index 0000000000..b75f731c44
--- /dev/null
+++ b/resolv/ns_name.c
@@ -0,0 +1,636 @@
+/*
+ * 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.
+ */
+
+#ifndef lint
+static const char rcsid[] = "$Id$";
+#endif
+
+#include <sys/types.h>
+
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+
+#include <errno.h>
+#include <resolv.h>
+#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. */
+
+/*
+ * 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
+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) {
+ /* Some kind of compression pointer. */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ if (dn != dst) {
+ if (dn >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = '.';
+ }
+ if (dn + n >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ for ((void)NULL; n > 0; n--) {
+ c = *cp++;
+ if (special(c)) {
+ if (dn + 1 >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = '\\';
+ *dn++ = (char)c;
+ } else if (!printable(c)) {
+ if (dn + 3 >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = '\\';
+ *dn++ = digits[c / 100];
+ *dn++ = digits[(c % 100) / 10];
+ *dn++ = digits[c % 10];
+ } else {
+ if (dn >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = (char)c;
+ }
+ }
+ }
+ if (dn == dst) {
+ if (dn >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = '.';
+ }
+ if (dn >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = '\0';
+ return (dn - dst);
+}
+
+/*
+ * 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
+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) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ n += (cp - digits) * 10;
+ if ((c = *src++) == 0 ||
+ (cp = strchr(digits, c)) == NULL) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ n += (cp - digits);
+ if (n > 255) {
+ __set_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. */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ if (label >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *label = c;
+ /* Fully qualified ? */
+ if (*src == '\0') {
+ if (c != 0) {
+ if (bp >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *bp++ = '\0';
+ }
+ if ((bp - dst) > MAXCDNAME) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ return (1);
+ }
+ if (c == 0 || *src == '.') {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ label = bp++;
+ continue;
+ }
+ if (bp >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *bp++ = (u_char)c;
+ }
+ c = (bp - label - 1);
+ if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ if (label >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *label = c;
+ if (c != 0) {
+ if (bp >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *bp++ = 0;
+ }
+ if ((bp - dst) > MAXCDNAME) { /* src too big */
+ __set_errno (EMSGSIZE);
+ 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. */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ *dn++ = n;
+ if (dn + n >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ for ((void)NULL; n > 0; n--) {
+ c = *cp++;
+ if (isupper(c))
+ *dn++ = tolower(c);
+ else
+ *dn++ = c;
+ }
+ }
+ *dn++ = '\0';
+ return (dn - dst);
+}
+
+/*
+ * 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
+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) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ /* Fetch next label in domain name. */
+ while ((n = *srcp++) != 0) {
+ /* Check for indirection. */
+ switch (n & NS_CMPRSFLGS) {
+ case 0:
+ /* Limit checks. */
+ if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ checked += n + 1;
+ *dstp++ = n;
+ memcpy(dstp, srcp, n);
+ dstp += n;
+ srcp += n;
+ break;
+
+ case NS_CMPRSFLGS:
+ if (srcp >= eom) {
+ __set_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. */
+ __set_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) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ break;
+
+ default:
+ __set_errno (EMSGSIZE);
+ 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;
+
+ 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) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ l += n + 1;
+ if (l > MAXCDNAME) {
+ __set_errno (EMSGSIZE);
+ 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 && 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) {
+ *cpp++ = dstp;
+ *cpp = NULL;
+ }
+ }
+ /* copy label to buffer */
+ if (n & NS_CMPRSFLGS) { /* Should not happen. */
+ goto cleanup;
+ }
+ 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;
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ return (dstp - dst);
+}
+
+/*
+ * 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
+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 = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
+ return (-1);
+ if (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 (ns_name_pton(src, tmp, sizeof tmp) == -1)
+ return (-1);
+ return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
+}
+
+/*
+ * 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
+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 */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ break;
+ }
+ if (cp > eom) {
+ __set_errno (EMSGSIZE);
+ 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++) {
+ dn = domain;
+ sp = cp = *cpp;
+ 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 */
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ }
+ next: ;
+ }
+ __set_errno (ENOENT);
+ return (-1);
+}
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