dhcpv4: introduce a reply_opts array

Add a simple array to record the options we want to send back. This is just a
placeholder in preparation for later patches.

Signed-off-by: David Härdeman <[email protected]>
Link: https://github.com/openwrt/odhcpd/pull/278
Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 7c18bca5be8dedb48054cff04834815efc2c4182..2a5a1d0a66dae4c981fb98fa30f70203234c8beb 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -676,6 +676,8 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
                .code = DHCPV4_OPT_DNR,
        };
        uint8_t reply_end = DHCPV4_OPT_END;
+       uint8_t *reply_opts;
+       size_t reply_opts_len = 0;
 
        struct iovec iov[IOV_TOTAL] = {
                [IOV_HEADER]    = { &reply, 0 },
@@ -834,6 +836,8 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
                return;
        }
 
+       reply_opts = alloca(req_opts_len + 32);
+
        if (a) {
                uint32_t val;
 
@@ -841,24 +845,30 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
 
                val = htonl(req_leasetime);
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_LEASETIME, 4, &val);
+               reply_opts[reply_opts_len++] = DHCPV4_OPT_LEASETIME;
 
                if (req_leasetime != UINT32_MAX) {
                        val = htonl(500 * req_leasetime / 1000);
                        dhcpv4_put(&reply, &cursor, DHCPV4_OPT_RENEW, 4, &val);
+                       reply_opts[reply_opts_len++] = DHCPV4_OPT_RENEW;
 
                        val = htonl(875 * req_leasetime / 1000);
                        dhcpv4_put(&reply, &cursor, DHCPV4_OPT_REBIND, 4, &val);
+                       reply_opts[reply_opts_len++] = DHCPV4_OPT_REBIND;
                }
 
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_NETMASK, 4,
                                &iface->dhcpv4_mask.s_addr);
+               reply_opts[reply_opts_len++] = DHCPV4_OPT_NETMASK;
 
                if (a->hostname)
                        dhcpv4_put(&reply, &cursor, DHCPV4_OPT_HOSTNAME,
                                        strlen(a->hostname), a->hostname);
+               reply_opts[reply_opts_len++] = DHCPV4_OPT_HOSTNAME;
 
                if (iface->dhcpv4_bcast.s_addr != INADDR_ANY)
                        dhcpv4_put(&reply, &cursor, DHCPV4_OPT_BROADCAST, 4, &iface->dhcpv4_bcast);
+               reply_opts[reply_opts_len++] = DHCPV4_OPT_BROADCAST;
 
                if (incl_fr_opt) {
                        if (req_msg == DHCPV4_MSG_REQUEST) {
@@ -873,10 +883,12 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
 
                                memcpy(auth.key, a->key, sizeof(auth.key));
                                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
+                               reply_opts[reply_opts_len++] = DHCPV4_OPT_AUTHENTICATION;
                        } else {
                                uint8_t one = 1;
                                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE,
                                        sizeof(one), &one);
+                               reply_opts[reply_opts_len++] = DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE;
                        }
                }
        }
@@ -889,6 +901,7 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
        if (!ioctl(iface->dhcpv4_event.uloop.fd, SIOCGIFMTU, &ifr)) {
                uint16_t mtu = htons(ifr.ifr_mtu);
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_MTU, 2, &mtu);
+               reply_opts[reply_opts_len++] = DHCPV4_OPT_MTU;
        }
 
        if (iface->search && iface->search_len <= 255)
@@ -902,13 +915,14 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
                        dhcpv4_put(&reply, &cursor, DHCPV4_OPT_SEARCH_DOMAIN,
                                        len, search_buf);
        }
+       reply_opts[reply_opts_len++] = DHCPV4_OPT_SEARCH_DOMAIN;
 
        if (iface->dhcpv4_router_cnt == 0)
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_ROUTER, 4, &iface->dhcpv4_local);
        else
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_ROUTER,
                                4 * iface->dhcpv4_router_cnt, iface->dhcpv4_router);
-
+       reply_opts[reply_opts_len++] = DHCPV4_OPT_ROUTER;
 
        if (iface->dhcpv4_dns_cnt == 0) {
                if (iface->dns_service)
@@ -916,9 +930,14 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
        } else
                dhcpv4_put(&reply, &cursor, DHCPV4_OPT_DNSSERVER,
                                4 * iface->dhcpv4_dns_cnt, iface->dhcpv4_dns);
+       reply_opts[reply_opts_len++] = DHCPV4_OPT_DNSSERVER;
+
+       memcpy(&reply_opts[reply_opts_len], req_opts, req_opts_len);
+       reply_opts_len += req_opts_len;
 
-       for (size_t opt = 0; opt < req_opts_len; opt++) {
-               switch (req_opts[opt]) {
+       /* Note: each option might get called more than once */
+       for (size_t i = 0; i < reply_opts_len; i++) {
+               switch (reply_opts[i]) {
                case DHCPV4_OPT_NTPSERVER:
                        if (!a)
                                break;