From acb98cb57d3d84f7f9410746ba82581d445158e1 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 6 May 2006 19:18:15 +0000 Subject: [PATCH] [BZ #2499] * resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Avoid possibly unaligned memory accesses. --- ChangeLog | 4 ++++ resolv/nss_dns/dns-canon.c | 16 +++++++++------- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/ChangeLog b/ChangeLog index 983502f..eec0c20 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2006-05-06 Ulrich Drepper + [BZ #2499] + * resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Avoid + possibly unaligned memory accesses. + * include/arpa/nameser.h: Also optimize NS_PUT16 and NS_PUT32. * resolv/res_mkquery.c: Use NS_PUT16 and NS_PUT32 instead of __putshort and __putlong respectively. Correct buffer overflow check for diff --git a/resolv/nss_dns/dns-canon.c b/resolv/nss_dns/dns-canon.c index 91708df..fca6cd8 100644 --- a/resolv/nss_dns/dns-canon.c +++ b/resolv/nss_dns/dns-canon.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2004 Free Software Foundation, Inc. +/* Copyright (C) 2004, 2006 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2004. @@ -40,6 +40,10 @@ typedef union querybuf } querybuf; +static const short int qtypes[] = { ns_t_a, ns_t_aaaa }; +#define nqtypes (sizeof (qtypes) / sizeof (qtypes[0])) + + enum nss_status _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen, char **result,int *errnop, int *h_errnop) @@ -53,8 +57,6 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen, unsigned char *ptr; } ansp = { .ptr = buf }; enum nss_status status = NSS_STATUS_UNAVAIL; - int qtypes[] = { ns_t_a, ns_t_aaaa }; -#define nqtypes (sizeof (qtypes) / sizeof (qtypes[0])) for (int i = 0; i < nqtypes; ++i) { @@ -101,7 +103,8 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen, ptr += s; /* Check whether type and class match. */ - unsigned int type = ntohs (*(uint16_t *) ptr); + uint_fast16_t type; + NS_GET16 (type, ptr); if (type == qtypes[i]) { /* We found the record. */ @@ -130,15 +133,14 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen, if (type != ns_t_cname) goto unavail; - ptr += sizeof (uint16_t); - if (*(uint16_t *) ptr != htons (ns_c_in)) + if (ns_get16 (ptr) != ns_c_in) goto unavail; /* Also skip over the TTL. */ ptr += sizeof (uint16_t) + sizeof (uint32_t); /* Skip over the data length and data. */ - ptr += sizeof (uint16_t) + ntohs (*(uint16_t *) ptr); + ptr += sizeof (uint16_t) + ns_get16 (ptr); } } } -- 2.7.4