Module Name: src
Committed By: christos
Date: Fri Jan 17 02:03:44 UTC 2014
Modified Files:
src/lib/libc/net: gethnamaddr.c
Log Message:
Move more code into the macro, and fix the bug where realloc would cause
a dangling pointer and memory corruption.
To generate a diff of this commit:
cvs rdiff -u -r1.86 -r1.87 src/lib/libc/net/gethnamaddr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/net/gethnamaddr.c
diff -u src/lib/libc/net/gethnamaddr.c:1.86 src/lib/libc/net/gethnamaddr.c:1.87
--- src/lib/libc/net/gethnamaddr.c:1.86 Thu Jan 16 15:59:21 2014
+++ src/lib/libc/net/gethnamaddr.c Thu Jan 16 21:03:44 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: gethnamaddr.c,v 1.86 2014/01/16 20:59:21 christos Exp $ */
+/* $NetBSD: gethnamaddr.c,v 1.87 2014/01/17 02:03:44 christos Exp $ */
/*
* ++Copyright++ 1985, 1988, 1993
@@ -57,7 +57,7 @@
static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93";
static char rcsid[] = "Id: gethnamaddr.c,v 8.21 1997/06/01 20:34:37 vixie Exp ";
#else
-__RCSID("$NetBSD: gethnamaddr.c,v 1.86 2014/01/16 20:59:21 christos Exp $");
+__RCSID("$NetBSD: gethnamaddr.c,v 1.87 2014/01/17 02:03:44 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
@@ -108,18 +108,22 @@ __weak_alias(gethostent,_gethostent)
#define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok)
#define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok)
-#define grow(arr, siz) do { \
- void *xptr = realloc(arr, siz + 10); \
- if (xptr == NULL) \
- goto nospc; \
- arr = xptr; \
- siz += 10; \
+#define addalias(d, s, arr, siz) do { \
+ if (d >= &arr[siz - 1]) { \
+ char **xptr = realloc(arr, siz + 10); \
+ if (xptr == NULL) \
+ goto nospc; \
+ d = xptr + (d - arr); \
+ arr = xptr; \
+ siz += 10; \
+ } \
+ *d++ = s; \
} while (/*CONSTCOND*/0)
-#define setup(arr, siz) do { \
- arr = malloc(siz = 10); \
- if (arr == NULL) \
- goto nospc; \
+#define setup(arr, siz) do { \
+ arr = malloc(siz = 10); \
+ if (arr == NULL) \
+ goto nospc; \
} while (/*CONSTCOND*/0)
@@ -307,8 +311,6 @@ getanswer(const querybuf *answer, int an
continue; /* XXX - had_error++ ? */
}
if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
- if (ap >= &aliases[maxaliases - 1])
- grow(aliases, maxaliases);
n = dn_expand(answer->buf, eom, cp, tbuf,
(int)sizeof tbuf);
if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) {
@@ -319,7 +321,7 @@ getanswer(const querybuf *answer, int an
if (cp != erdata)
goto no_recovery;
/* Store alias. */
- *ap++ = bp;
+ addalias(ap, bp, aliases, maxaliases);
n = (int)strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
@@ -386,11 +388,8 @@ getanswer(const querybuf *answer, int an
goto no_recovery;
if (!haveanswer)
hent->h_name = bp;
- else {
- if (ap >= &aliases[maxaliases - 1])
- grow(aliases, maxaliases);
- *ap++ = bp;
- }
+ else
+ addalias(ap, bp, aliases, maxaliases);
if (n != -1) {
n = (int)strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
@@ -808,8 +807,7 @@ gethostent_r(FILE *hf, struct hostent *h
cp++;
continue;
}
- if (q >= &aliases[maxaliases - 1])
- grow(aliases, maxaliases);
+ addalias(q, cp, aliases, maxaliases);
*q++ = cp;
if ((cp = strpbrk(cp, " \t")) != NULL)
*cp++ = '\0';
@@ -1173,11 +1171,8 @@ nextline:
hp->h_name = p;
else if (strcmp(hp->h_name, p) == 0)
;
- else {
- if (q >= &aliases[maxaliases - 1])
- grow(aliases, maxaliases);
- *q++ = p;
- }
+ else
+ addalias(q, p, aliases, maxaliases);
p = cp;
if (more)
goto nextline;
@@ -1191,8 +1186,7 @@ nextline:
cp++;
goto nextline;
}
- if (q >= &aliases[maxaliases - 1])
- grow(aliases, maxaliases);
+ addalias(q, cp, aliases, maxaliases);
*q++ = cp;
cp = strpbrk(cp, " \t");
if (cp != NULL)
