iptables/0011-extensions-libebt_ip6-...

110 lines
3.3 KiB
Diff

From 4ddde566b4af111536918b17e558c7bb4531335f Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Wed, 2 Jun 2021 14:04:43 +0200
Subject: [PATCH] extensions: libebt_ip6: Use xtables_ip6parse_any()
The code was almost identical and suffered from the same problem as
fixed in commit a76a5c997a235 ("libxtables: fix two off-by-one memory
corruption bugs").
The only functional change this involves is ebt_parse_ip6_address() will
now accept hostnames as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
(cherry picked from commit ca840c20b7b754d36a1abe7e597fd730dea142d4)
---
extensions/libebt_ip6.c | 74 ++++++-----------------------------------
1 file changed, 10 insertions(+), 64 deletions(-)
diff --git a/extensions/libebt_ip6.c b/extensions/libebt_ip6.c
index 301bed9aadefd..3cc39271d4658 100644
--- a/extensions/libebt_ip6.c
+++ b/extensions/libebt_ip6.c
@@ -247,73 +247,19 @@ static void brip6_init(struct xt_entry_match *match)
memset(ipinfo->dmsk.s6_addr, 0, sizeof(ipinfo->dmsk.s6_addr));
}
-static struct in6_addr *numeric_to_addr(const char *num)
+/* wrap xtables_ip6parse_any(), ignoring any but the first returned address */
+static void ebt_parse_ip6_address(char *address,
+ struct in6_addr *addr, struct in6_addr *msk)
{
- static struct in6_addr ap;
-
- if (inet_pton(AF_INET6, num, &ap) == 1)
- return &ap;
- return (struct in6_addr *)NULL;
-}
-
-static struct in6_addr *parse_ip6_mask(char *mask)
-{
- static struct in6_addr maskaddr;
struct in6_addr *addrp;
- unsigned int bits;
-
- if (mask == NULL) {
- /* no mask at all defaults to 128 bits */
- memset(&maskaddr, 0xff, sizeof maskaddr);
- return &maskaddr;
- }
- if ((addrp = numeric_to_addr(mask)) != NULL)
- return addrp;
- if (!xtables_strtoui(mask, NULL, &bits, 0, 128))
- xtables_error(PARAMETER_PROBLEM, "Invalid IPv6 Mask '%s' specified", mask);
- if (bits != 0) {
- char *p = (char *)&maskaddr;
- memset(p, 0xff, bits / 8);
- memset(p + (bits / 8) + 1, 0, (128 - bits) / 8);
- p[bits / 8] = 0xff << (8 - (bits & 7));
- return &maskaddr;
- }
+ unsigned int naddrs;
- memset(&maskaddr, 0, sizeof maskaddr);
- return &maskaddr;
-}
-
-/* Set the ipv6 mask and address. Callers should check ebt_errormsg[0].
- * The string pointed to by address can be altered. */
-static void ebt_parse_ip6_address(char *address, struct in6_addr *addr, struct in6_addr *msk)
-{
- struct in6_addr *tmp_addr;
- char buf[256];
- char *p;
- int i;
-
- strncpy(buf, address, sizeof(buf) - 1);
- /* first the mask */
- buf[sizeof(buf) - 1] = '\0';
- if ((p = strrchr(buf, '/')) != NULL) {
- *p = '\0';
- tmp_addr = parse_ip6_mask(p + 1);
- } else
- tmp_addr = parse_ip6_mask(NULL);
-
- *msk = *tmp_addr;
-
- /* if a null mask is given, the name is ignored, like in "any/0" */
- if (!memcmp(msk, &in6addr_any, sizeof(in6addr_any)))
- strcpy(buf, "::");
-
- if (inet_pton(AF_INET6, buf, addr) < 1) {
- xtables_error(PARAMETER_PROBLEM, "Invalid IPv6 Address '%s' specified", buf);
- return;
- }
-
- for (i = 0; i < 4; i++)
- addr->s6_addr32[i] &= msk->s6_addr32[i];
+ xtables_ip6parse_any(address, &addrp, msk, &naddrs);
+ if (naddrs != 1)
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid IPv6 Address '%s' specified", address);
+ memcpy(addr, addrp, sizeof(*addr));
+ free(addrp);
}
#define OPT_SOURCE 0x01
--
2.31.1