dhcpc.c: Added support for relay server parameter.

Resolved a TODO by adding support for gateway_nip parameter.

function                                             old     new   delta
udhcp_run_script                                     792     835     +43

Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 739870bee..80391f606 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -449,15 +449,16 @@ static char **fill_envp(struct dhcp_packet *packet)
 
         memset(found_opts, 0, sizeof(found_opts));
 
-        /* We need 6 elements for:
+        /* We need 7 elements for:
          * "interface=IFACE"
          * "ip=N.N.N.N" from packet->yiaddr
+         * "giaddr=IP" from packet->gateway_nip (unless 0)
          * "siaddr=IP" from packet->siaddr_nip (unless 0)
          * "boot_file=FILE" from packet->file (unless overloaded)
          * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
          * terminating NULL
          */
-        envc = 6;
+        envc = 7;
         /* +1 element for each option, +2 for subnet option: */
         if (packet) {
                 /* note: do not search for "pad" (0) and "end" (255) options */
@@ -493,9 +494,7 @@ static char **fill_envp(struct dhcp_packet *packet)
          * uint16_t flags;  // only one flag so far: bcast. Never set by server
          * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
          *                  // if during renew server wants to give us different IP?)
-         * uint32_t gateway_nip; // relay agent IP address
          * uint8_t chaddr[16]; // link-layer client hardware address (MAC)
-         * TODO: export gateway_nip as $giaddr?
          */
         /* Most important one: yiaddr as $ip */
         *curr = xmalloc(sizeof("ip=255.255.255.255"));
@@ -507,6 +506,12 @@ static char **fill_envp(struct dhcp_packet *packet)
                 sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
                 putenv(*curr++);
         }
+        if (packet->gateway_nip) {
+                /* IP address of DHCP relay agent to use in bootstrap */
+                *curr = xmalloc(sizeof("giaddr=255.255.255.255"));
+                sprint_nip(*curr, "giaddr=", (uint8_t *) &packet->gateway_nip);
+                putenv(*curr++);
+        }
         if (!(overload & FILE_FIELD) && packet->file[0]) {
                 /* watch out for invalid packets */
                 *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);