dhcpv4: dhcpv4_lease() - clarify which variables are requests

By consistently using the "req_" prefix, it's clearer which variables
relate to things the client has requested or which come from the client
request.

Signed-off-by: David Härdeman <[email protected]>
Link: https://github.com/openwrt/odhcpd/pull/286
Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 93e756271259801c304d87fc5539823b8964f8a2..372b2d344a6966c9f43335e9e6376c1490d756fb 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -440,14 +440,14 @@ static struct dhcp_assignment *find_assignment_by_hwaddr(struct interface *iface
        return NULL;
 }
 
-static struct dhcp_assignment*
-dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
-            const uint32_t reqaddr, uint32_t *leasetime, const char *hostname,
-            const size_t hostname_len, const bool accept_fr_nonce, bool *incl_fr_opt,
+static struct dhcp_assignment *
+dhcpv4_lease(struct interface *iface, enum dhcpv4_msg req_msg, const uint8_t *req_mac,
+            const uint32_t req_addr, uint32_t *req_leasetime, const char *req_hostname,
+            const size_t req_hostname_len, const bool req_accept_fr, bool *reply_incl_fr,
             uint32_t *fr_serverid)
 {
-       struct dhcp_assignment *a = find_assignment_by_hwaddr(iface, mac);
-       struct lease *l = config_find_lease_by_mac(mac);
+       struct dhcp_assignment *a = find_assignment_by_hwaddr(iface, req_mac);
+       struct lease *l = config_find_lease_by_mac(req_mac);
        time_t now = odhcpd_time();
 
        /*
@@ -455,7 +455,7 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
         * hwaddr, we need to clear out any old assignments given to other
         * hwaddrs in order to take over the IP address.
         */
-       if (l && !a && (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST)) {
+       if (l && !a && (req_msg == DHCPV4_MSG_DISCOVER || req_msg == DHCPV4_MSG_REQUEST)) {
                struct dhcp_assignment *c, *tmp;
 
                list_for_each_entry_safe(c, tmp, &l->assignments, lease_list) {
@@ -474,12 +474,12 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                dhcpv4_fr_stop(a);
        }
 
-       switch (msg) {
+       switch (req_msg) {
        case DHCPV4_MSG_RELEASE:
                if (!a)
                        return NULL;
 
-               ubus_bcast_dhcp_event("dhcp.release", mac,
+               ubus_bcast_dhcp_event("dhcp.release", req_mac,
                                      (struct in_addr *)&a->addr,
                                      a->hostname, iface->ifname);
                free_assignment(a);
@@ -514,7 +514,7 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                        /* Try to reassign to an address that is in-scope */
                        list_del_init(&a->head);
                        a->addr = INADDR_ANY;
-                       if (!dhcpv4_assign(iface, a, reqaddr)) {
+                       if (!dhcpv4_assign(iface, a, req_addr)) {
                                free_assignment(a);
                                a = NULL;
                                break;
@@ -529,7 +529,7 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                                return NULL;
                        }
 
-                       memcpy(a->hwaddr, mac, sizeof(a->hwaddr));
+                       memcpy(a->hwaddr, req_mac, sizeof(a->hwaddr));
                        a->dhcp_free_cb = dhcpv4_free_assignment;
                        a->iface = iface;
                        a->flags = OAF_DHCPV4;
@@ -538,7 +538,7 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                        a->valid_until = l ? 0 : now;
                        a->addr = l ? l->ipaddr : INADDR_ANY;
 
-                       if (!dhcpv4_assign(iface, a, reqaddr)) {
+                       if (!dhcpv4_assign(iface, a, req_addr)) {
                                free_assignment(a);
                                return NULL;
                        }
@@ -557,27 +557,29 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                        }
                }
 
+               /* See if we need to clamp the requested leasetime */
                uint32_t my_leasetime;
                if (a->leasetime)
                        my_leasetime = a->leasetime;
                else
                        my_leasetime = iface->dhcp_leasetime;
 
-               if ((*leasetime == 0) || (my_leasetime < *leasetime))
-                       *leasetime = my_leasetime;
+               if ((*req_leasetime == 0) || (my_leasetime < *req_leasetime))
+                       *req_leasetime = my_leasetime;
 
-               if (msg == DHCPV4_MSG_DISCOVER) {
+               if (req_msg == DHCPV4_MSG_DISCOVER) {
                        a->flags &= ~OAF_BOUND;
-                       *incl_fr_opt = accept_fr_nonce;
+                       *reply_incl_fr = req_accept_fr;
                        a->valid_until = now;
                        break;
                }
 
-               if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
-                       a->hostname = realloc(a->hostname, hostname_len + 1);
-                       if (a->hostname) {
-                               memcpy(a->hostname, hostname, hostname_len);
-                               a->hostname[hostname_len] = 0;
+               if ((!(a->flags & OAF_STATIC) || !a->hostname) && req_hostname_len > 0) {
+                       char *new_name = realloc(a->hostname, req_hostname_len + 1);
+                       if (new_name) {
+                               a->hostname = new_name;
+                               memcpy(a->hostname, req_hostname, req_hostname_len);
+                               a->hostname[req_hostname_len] = 0;
 
                                if (odhcpd_valid_hostname(a->hostname))
                                        a->flags &= ~OAF_BROKEN_HOSTNAME;
@@ -586,17 +588,21 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
                        }
                }
 
+               *reply_incl_fr = false;
                if (!(a->flags & OAF_BOUND)) {
                        /* This is the client's first request for the address */
-                       a->accept_fr_nonce = accept_fr_nonce;
-                       *incl_fr_opt = accept_fr_nonce;
-                       odhcpd_urandom(a->key, sizeof(a->key));
+                       if (req_accept_fr) {
+                               a->accept_fr_nonce = true;
+                               *reply_incl_fr = true;
+                               odhcpd_urandom(a->key, sizeof(a->key));
+                       }
                        a->flags |= OAF_BOUND;
-               } else {
-                       *incl_fr_opt = false;
                }
 
-               a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime));
+               if (*req_leasetime == UINT32_MAX)
+                       a->valid_until = 0;
+               else
+                       a->valid_until = (time_t)(now + *req_leasetime);
                break;
 
        default:
@@ -849,7 +855,7 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
 
        /* Misc */
        struct sockaddr_in dest_addr;
-       bool incl_fr_opt = false;
+       bool reply_incl_fr = false;
        struct dhcp_assignment *a = NULL;
        uint32_t fr_serverid = INADDR_ANY;
 
@@ -936,14 +942,14 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
        case DHCPV4_MSG_RELEASE:
                dhcpv4_lease(iface, req_msg, req->chaddr, req_addr,
                             &req_leasetime, req_hostname, req_hostname_len,
-                            req_accept_fr, &incl_fr_opt, &fr_serverid);
+                            req_accept_fr, &reply_incl_fr, &fr_serverid);
                return;
        case DHCPV4_MSG_DISCOVER:
                _fallthrough;
        case DHCPV4_MSG_REQUEST:
                a = dhcpv4_lease(iface, req_msg, req->chaddr, req_addr,
                                 &req_leasetime, req_hostname, req_hostname_len,
-                                req_accept_fr, &incl_fr_opt, &fr_serverid);
+                                req_accept_fr, &reply_incl_fr, &fr_serverid);
                break;
        default:
                return;
@@ -1085,7 +1091,7 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
                        break;
 
                case DHCPV4_OPT_AUTHENTICATION:
-                       if (!a || !incl_fr_opt || req_msg != DHCPV4_MSG_REQUEST)
+                       if (!a || !reply_incl_fr || req_msg != DHCPV4_MSG_REQUEST)
                                break;
 
                        memcpy(reply_auth_body.key, a->key, sizeof(reply_auth_body.key));
@@ -1123,7 +1129,7 @@ void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
                        break;
 
                case DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE:
-                       if (!a || !incl_fr_opt || req_msg == DHCPV4_MSG_REQUEST)
+                       if (!a || !reply_incl_fr || req_msg == DHCPV4_MSG_REQUEST)
                                break;
 
                        iov[IOV_FR_NONCE_CAP].iov_len = sizeof(reply_fr_nonce_cap);