Author: melifaro
Date: Thu Nov 28 10:28:28 2013
New Revision: 258708
URL: http://svnweb.freebsd.org/changeset/base/258708
Log:
Check ipfw table numbers in both user and kernel space before rule addition.
Found by: Saychik Pavel <u...@localka.net>
MFC after: 2 weeks
Sponsored by: Yandex LLC
Modified:
head/sbin/ipfw/ipfw2.c
head/sbin/ipfw/ipfw2.h
head/sys/netpfil/ipfw/ip_fw_sockopt.c
Modified: head/sbin/ipfw/ipfw2.c
==============================================================================
--- head/sbin/ipfw/ipfw2.c Thu Nov 28 10:04:53 2013 (r258707)
+++ head/sbin/ipfw/ipfw2.c Thu Nov 28 10:28:28 2013 (r258708)
@@ -60,6 +60,8 @@ int resvd_set_number = RESVD_SET;
int ipfw_socket = -1;
+uint32_t ipfw_tables_max = 0; /* Number of tables supported by kernel */
+
#ifndef s6_addr32
#define s6_addr32 __u6_addr.__u6_addr32
#endif
@@ -2203,6 +2205,7 @@ fill_ip(ipfw_insn_ip *cmd, char *av, int
{
int len = 0;
uint32_t *d = ((ipfw_insn_u32 *)cmd)->d;
+ uint32_t tables_max;
cmd->o.len &= ~F_LEN_MASK; /* zero len */
@@ -2221,6 +2224,10 @@ fill_ip(ipfw_insn_ip *cmd, char *av, int
*p++ = '\0';
cmd->o.opcode = O_IP_DST_LOOKUP;
cmd->o.arg1 = strtoul(av + 6, NULL, 0);
+ tables_max = ipfw_get_tables_max();
+ if (cmd->o.arg1 > tables_max)
+ errx(EX_USAGE, "The table number exceeds the maximum "
+ "allowed value (%u)", tables_max - 1);
if (p) {
cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32);
d[0] = strtoul(p, NULL, 0);
@@ -4119,6 +4126,33 @@ static void table_list(uint16_t num, int
static void table_fill_xentry(char *arg, ipfw_table_xentry *xent);
/*
+ * Retrieve maximum number of tables supported by ipfw(4) module.
+ */
+uint32_t
+ipfw_get_tables_max()
+{
+ size_t len;
+ uint32_t tables_max;
+
+ if (ipfw_tables_max != 0)
+ return (ipfw_tables_max);
+
+ len = sizeof(tables_max);
+ if (sysctlbyname("net.inet.ip.fw.tables_max", &tables_max, &len,
+ NULL, 0) == -1) {
+ if (co.test_only)
+ tables_max = 128; /* Old conservative default */
+ else
+ errx(1, "Can't determine maximum number of ipfw tables."
+ " Perhaps you forgot to load ipfw module?");
+ }
+
+ ipfw_tables_max = tables_max;
+
+ return (ipfw_tables_max);
+}
+
+/*
* This one handles all table-related commands
* ipfw table N add addr[/masklen] [value]
* ipfw table N delete addr[/masklen]
@@ -4131,19 +4165,10 @@ ipfw_table_handler(int ac, char *av[])
ipfw_table_xentry xent;
int do_add;
int is_all;
- size_t len;
uint32_t a;
uint32_t tables_max;
- len = sizeof(tables_max);
- if (sysctlbyname("net.inet.ip.fw.tables_max", &tables_max, &len,
- NULL, 0) == -1) {
- if (co.test_only)
- tables_max = 128; /* Old conservative default */
- else
- errx(1, "Can't determine maximum number of ipfw tables."
- " Perhaps you forgot to load ipfw module?");
- }
+ tables_max = ipfw_get_tables_max();
memset(&xent, 0, sizeof(xent));
Modified: head/sbin/ipfw/ipfw2.h
==============================================================================
--- head/sbin/ipfw/ipfw2.h Thu Nov 28 10:04:53 2013 (r258707)
+++ head/sbin/ipfw/ipfw2.h Thu Nov 28 10:28:28 2013 (r258708)
@@ -228,6 +228,8 @@ char const *match_value(struct _s_x *p,
int do_cmd(int optname, void *optval, uintptr_t optlen);
+uint32_t ipfw_get_tables_max(void);
+
struct in6_addr;
void n2mask(struct in6_addr *mask, int n);
int contigmask(uint8_t *p, int len);
Modified: head/sys/netpfil/ipfw/ip_fw_sockopt.c
==============================================================================
--- head/sys/netpfil/ipfw/ip_fw_sockopt.c Thu Nov 28 10:04:53 2013
(r258707)
+++ head/sys/netpfil/ipfw/ip_fw_sockopt.c Thu Nov 28 10:28:28 2013
(r258708)
@@ -653,7 +653,7 @@ check_ipfw_struct(struct ip_fw *rule, in
case O_IP_SRC_LOOKUP:
case O_IP_DST_LOOKUP:
- if (cmd->arg1 >= IPFW_TABLES_MAX) {
+ if (cmd->arg1 >= V_fw_tables_max) {
printf("ipfw: invalid table number %d\n",
cmd->arg1);
return (EINVAL);
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