From 7ed1ac6da3d6ae5bfbbf4c4bdce07a40e8113df8 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 19 Jul 2021 07:55:27 +0200 Subject: resolv: Move ns_name_pack into its own file and into libc And reformat to GNU style, and eliminate the labellen function. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- resolv/Makefile | 1 + resolv/Versions | 4 +- resolv/ns_name.c | 194 ------------------------------------------------ resolv/ns_name_pack.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 206 insertions(+), 195 deletions(-) create mode 100644 resolv/ns_name_pack.c (limited to 'resolv') diff --git a/resolv/Makefile b/resolv/Makefile index 7839e1f..8bb2585 100644 --- a/resolv/Makefile +++ b/resolv/Makefile @@ -33,6 +33,7 @@ routines := \ inet_ntop \ inet_pton \ ns_name_ntop \ + ns_name_pack \ ns_name_pton \ ns_name_skip \ ns_name_uncompress \ diff --git a/resolv/Versions b/resolv/Versions index 770a2b8..8ea42da 100644 --- a/resolv/Versions +++ b/resolv/Versions @@ -26,6 +26,7 @@ libc { } GLIBC_2.9 { ns_name_ntop; + ns_name_pack; ns_name_pton; ns_name_skip; ns_name_uncompress; @@ -39,6 +40,7 @@ libc { getaddrinfo_a; %endif ns_name_ntop; + ns_name_pack; ns_name_pton; ns_name_skip; ns_name_uncompress; @@ -52,6 +54,7 @@ libc { __inet_aton_exact; __inet_pton_length; __ns_name_ntop; + __ns_name_pack; __ns_name_pton; __ns_name_skip; __ns_name_uncompress; @@ -154,7 +157,6 @@ libresolv { ns_msg_getflag; ns_name_compress; ns_name_ntol; - ns_name_pack; ns_name_pton; ns_name_rollback; ns_name_skip; diff --git a/resolv/ns_name.c b/resolv/ns_name.c index 9f7ca4a..f1a84ad 100644 --- a/resolv/ns_name.c +++ b/resolv/ns_name.c @@ -31,9 +31,6 @@ /* Forward. */ -static int dn_find(const u_char *, const u_char *, - const u_char * const *, - const u_char * const *); static int labellen(const u_char *); /* Public. */ @@ -93,118 +90,6 @@ ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) } /*% - * Pack domain name 'domain' into 'comp_dn'. - * - * return: - *\li Size of the compressed name, or -1. - * - * notes: - *\li 'dnptrs' is an array of pointers to previous compressed names. - *\li dnptrs[0] is a pointer to the beginning of the message. The array - * ends with NULL. - *\li 'lastdnptr' is a pointer to the end of the array pointed to - * by 'dnptrs'. - * - * Side effects: - *\li 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 { - int l0; - - n = *srcp; - if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { - __set_errno (EMSGSIZE); - return (-1); - } - if ((l0 = labellen(srcp)) < 0) { - __set_errno (EINVAL); - return(-1); - } - l += l0 + 1; - if (l > MAXCDNAME) { - __set_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 = 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) == NS_CMPRSFLGS) { - /* Should not happen. */ - goto cleanup; - } - n = labellen(srcp); - if (n + 1 > eob - dstp) { - 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); -} -libresolv_hidden_def (ns_name_pack) - -/*% * Compress a domain name into wire format, using compression pointers. * * return: @@ -250,85 +135,6 @@ ns_name_rollback(const u_char *src, const u_char **dnptrs, /* Private. */ -/*% - * 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); -} - -/*% - * Search for the counted-label name in an array of compressed names. - * - * return: - *\li offset from msg if found, or -1. - * - * notes: - *\li dnptrs is the pointer to the first name on the list, - *\li 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 */ - 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 */ - __set_errno (EMSGSIZE); - return (-1); - } - } - next: ; - sp += *sp + 1; - } - } - __set_errno (ENOENT); - return (-1); -} - /* Return the length of the encoded label starting at LP, or -1 for compression references and extended label types. */ static int diff --git a/resolv/ns_name_pack.c b/resolv/ns_name_pack.c new file mode 100644 index 0000000..3200b78 --- /dev/null +++ b/resolv/ns_name_pack.c @@ -0,0 +1,202 @@ +/* Compression of DNS domain names. + * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") + * 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 ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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 +#include +#include +#include + +/* 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 >= 'A' && ch <= 'Z') + return ch - 'A' + 'a'; + return ch; +} + +/* Search for the counted-label name in an array of compressed names. + Returns the offset from MSG if found, or -1. + + 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 unsigned char *domain, const unsigned char *msg, + const unsigned char **dnptrs, + const unsigned char **lastdnptr) +{ + const unsigned char *dn, *cp, *sp; + const unsigned char **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. */ + if (n != *dn++) + goto next; + + for (; 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: ; + sp += *sp + 1; + } + } + __set_errno (ENOENT); + return -1; +} + +/* Packs domain name SRC into DST. Returns size of the compressed + name, or -1. + + 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'. + + The list of pointers in DNPTRS is updated for labels inserted into + the message as we compress the name. If DNPTRS is NULL, we don't + try to compress names. If LASTDNPTR is NULL, we don't update the + list. */ +int +___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++) + ; + 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 >= 64) + { + __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, dnptrs, lpp); + if (l >= 0) + { + if (eob - dstp <= 1) + 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 >= 64) + /* Should not happen. */ + goto cleanup; + if (n + 1 > eob - dstp) + 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; +} +versioned_symbol (libc, ___ns_name_pack, ns_name_pack, GLIBC_2_34); +versioned_symbol (libc, ___ns_name_pack, __ns_name_pack, GLIBC_PRIVATE); +libc_hidden_ver (___ns_name_pack, __ns_name_pack) + +#if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34) +compat_symbol (libresolv, ___ns_name_pack, ns_name_pack, GLIBC_2_9); +#endif -- cgit v1.1