udhcpc: check that 4-byte options are indeed 4-byte, closes 11506

function                                             old     new   delta
udhcp_get_option32                                     -      27     +27
udhcp_get_option                                     231     248     +17
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 44/0)               Total: 44 bytes

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

1 files changed, 3 insertions, 3 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 4b23e4d39..5b3fd531c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1691,7 +1691,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
  * They say ISC DHCP client supports this case.
  */
                                 server_addr = 0;
-                                temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
+                                temp = udhcp_get_option32(&packet, DHCP_SERVER_ID);
                                 if (!temp) {
                                         bb_error_msg("no server ID, using 0.0.0.0");
                                 } else {
@@ -1718,7 +1718,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 struct in_addr temp_addr;
                                 uint8_t *temp;
 
-                                temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
+                                temp = udhcp_get_option32(&packet, DHCP_LEASE_TIME);
                                 if (!temp) {
                                         bb_error_msg("no lease time with ACK, using 1 hour lease");
                                         lease_seconds = 60 * 60;
@@ -1813,7 +1813,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         uint32_t svid;
                                         uint8_t *temp;
 
-                                        temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
+                                        temp = udhcp_get_option32(&packet, DHCP_SERVER_ID);
                                         if (!temp) {
  non_matching_svid:
                                                 log1("received DHCP NAK with wrong"