udhcpc: when decoding DHCP_SUBNET, ensure it is 4 bytes long

function                                             old     new   delta
udhcp_run_script                                     795     801      +6

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 4c2221b77fb93fd67470bf5ac2dcad4898840369..fc4de5716e1ff5ef4b33ba471121fc0683c5b50d 100644 (file)
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -302,7 +302,7 @@ uint8_t* FAST_FUNC udhcp_get_option32(struct dhcp_packet *packet, int code)
 {
        uint8_t *r = udhcp_get_option(packet, code);
        if (r) {
-               if (r[-1] != 4)
+               if (r[-OPT_DATA + OPT_LEN] != 4)
                        r = NULL;
        }
        return r;

diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index 9511152ff49946f957ca2937c277dda5869c4456..62f9a2a4aa81db1a353702dc92891b6b37ac0b11 100644 (file)
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -119,7 +119,7 @@ enum {
 //#define DHCP_TIME_SERVER      0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */
 //#define DHCP_NAME_SERVER      0x05 /* IEN 116 _really_ ancient kind of NS */
 //#define DHCP_DNS_SERVER       0x06
-//#define DHCP_LOG_SERVER       0x07 /* port 704 UDP log (not syslog)
+//#define DHCP_LOG_SERVER       0x07 /* port 704 UDP log (not syslog) */
 //#define DHCP_COOKIE_SERVER    0x08 /* "quote of the day" server */
 //#define DHCP_LPR_SERVER       0x09
 #define DHCP_HOST_NAME          0x0c /* 12: either client informs server or server gives name to client */

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 5b3fd531caeb3f31a21682b2c31a6b1155b8fd77..dcec8cdfd19363b6ca704352145a90403136add5 100644 (file)
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -531,7 +531,7 @@ static char **fill_envp(struct dhcp_packet *packet)
                temp = udhcp_get_option(packet, code);
                *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
                putenv(*curr++);
-               if (code == DHCP_SUBNET) {
+               if (code == DHCP_SUBNET && temp[-OPT_DATA + OPT_LEN] == 4) {
                        /* Subnet option: make things like "$ip/$mask" possible */
                        uint32_t subnet;
                        move_from_unaligned32(subnet, temp);