dhcpv4: rename cookie variable

The name is potentially confusing given that DHCPv4 includes the concept of a
magic cookie.  The variable is actually used as a cursor/write ptr, so rename
it to something more descriptive.

Signed-off-by: David Härdeman <[email protected]>
Link: https://github.com/openwrt/odhcpd/pull/266
Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 733ab4ad7b0065e80827868b009851dd49e65947..fe0d869172fdbaa3b601f17b8fa02331965209a8 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -133,18 +133,18 @@ static const char *dhcpv4_msg_to_string(uint8_t reqmsg)
        return dhcpv4_msg_names[reqmsg];
 }
 
-static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie,
+static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cursor,
                uint8_t type, uint8_t len, const void *data)
 {
-       uint8_t *c = *cookie;
+       uint8_t *c = *cursor;
        uint8_t *end = (uint8_t *)msg + sizeof(*msg);
        bool tag_only = type == DHCPV4_OPT_PAD || type == DHCPV4_OPT_END;
        int total_len = tag_only ? 1 : 2 + len;
 
-       if (*cookie + total_len > end)
+       if (*cursor + total_len > end)
                return;
 
-       *cookie += total_len;
+       *cursor += total_len;
        *c++ = type;
 
        if (tag_only)
@@ -185,14 +185,14 @@ static void dhcpv4_fr_send(struct dhcp_assignment *a)
        odhcpd_urandom(&fr_msg.xid, sizeof(fr_msg.xid));
        memcpy(fr_msg.chaddr, a->hwaddr, fr_msg.hlen);
 
-       uint8_t *cookie = &fr_msg.options[DHCPV4_MAGIC_COOKIE_LEN];
+       uint8_t *cursor = &fr_msg.options[DHCPV4_MAGIC_COOKIE_LEN];
        uint8_t msg = DHCPV4_MSG_FORCERENEW;
 
-       dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_MESSAGE, sizeof(msg), &msg);
+       dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_MESSAGE, sizeof(msg), &msg);
        if (a->accept_fr_nonce) {
-               dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
-               auth_o = (struct dhcpv4_auth_forcerenew *)(cookie - sizeof(auth));
-               dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL);
+               dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
+               auth_o = (struct dhcpv4_auth_forcerenew *)(cursor - sizeof(auth));
+               dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_END, 0, NULL);
 
                md5_ctx_t md5;
                uint8_t secretbytes[64];
@@ -217,9 +217,9 @@ static void dhcpv4_fr_send(struct dhcp_assignment *a)
                md5_hash(auth_o->key, sizeof(auth_o->key), &md5);
                md5_end(auth_o->key, &md5);
        } else {
-               dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_SERVERID, 4,
+               dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_SERVERID, 4,
                                &a->fr_ip->addr.addr.in.s_addr);
-               dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL);
+               dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_END, 0, NULL);
        }
 
        struct sockaddr_in dest;
@@ -228,7 +228,7 @@ static void dhcpv4_fr_send(struct dhcp_assignment *a)
        dest.sin_port = htons(DHCPV4_CLIENT_PORT);
        dest.sin_addr.s_addr = a->addr;
 
-       if (sendto(iface->dhcpv4_event.uloop.fd, &fr_msg, PACKET_SIZE(&fr_msg, cookie),
+       if (sendto(iface->dhcpv4_event.uloop.fd, &fr_msg, PACKET_SIZE(&fr_msg, cursor),
                        MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)) < 0)
                syslog(LOG_ERR, "Failed to send %s to %s - %s: %m", dhcpv4_msg_to_string(msg),
                        odhcpd_print_mac(a->hwaddr, sizeof(a->hwaddr)), inet_ntoa(dest.sin_addr));
@@ -594,7 +594,7 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
        };
        memcpy(reply.chaddr, req->chaddr, sizeof(reply.chaddr));
 
-       uint8_t *cookie = &reply.options[DHCPV4_MAGIC_COOKIE_LEN];
+       uint8_t *cursor = &reply.options[DHCPV4_MAGIC_COOKIE_LEN];
        uint8_t reqmsg = DHCPV4_MSG_REQUEST;
        uint8_t msg = DHCPV4_MSG_ACK;
 
@@ -710,8 +710,8 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
        if (reqmsg == DHCPV4_MSG_DECLINE || reqmsg == DHCPV4_MSG_RELEASE)
                return;
 
-       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MESSAGE, 1, &msg);
-       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SERVERID, 4, &serverid);
+       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_MESSAGE, 1, &msg);
+       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_SERVERID, 4, &serverid);
 
        if (a) {
                uint32_t val;
@@ -719,25 +719,25 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
                reply.yiaddr.s_addr = a->addr;
 
                val = htonl(leasetime);
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_LEASETIME, 4, &val);
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_LEASETIME, 4, &val);
 
                if (leasetime != UINT32_MAX) {
                        val = htonl(500 * leasetime / 1000);
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_RENEW, 4, &val);
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_RENEW, 4, &val);
 
                        val = htonl(875 * leasetime / 1000);
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_REBIND, 4, &val);
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_REBIND, 4, &val);
                }
 
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4,
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_NETMASK, 4,
                                &iface->dhcpv4_mask.s_addr);
 
                if (a->hostname)
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_HOSTNAME,
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_HOSTNAME,
                                        strlen(a->hostname), a->hostname);
 
                if (iface->dhcpv4_bcast.s_addr != INADDR_ANY)
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_BROADCAST, 4, &iface->dhcpv4_bcast);
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_BROADCAST, 4, &iface->dhcpv4_bcast);
 
                if (incl_fr_opt) {
                        if (reqmsg == DHCPV4_MSG_REQUEST) {
@@ -751,10 +751,10 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
                                };
 
                                memcpy(auth.key, a->key, sizeof(auth.key));
-                               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
+                               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
                        } else {
                                uint8_t one = 1;
-                               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE,
+                               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE,
                                        sizeof(one), &one);
                        }
                }
@@ -767,39 +767,39 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
 
        if (!ioctl(sock, SIOCGIFMTU, &ifr)) {
                uint16_t mtu = htons(ifr.ifr_mtu);
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MTU, 2, &mtu);
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_MTU, 2, &mtu);
        }
 
        if (iface->search && iface->search_len <= 255)
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN,
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_SEARCH_DOMAIN,
                                iface->search_len, iface->search);
        else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
                uint8_t search_buf[256];
                int len = dn_comp(_res.dnsrch[0], search_buf,
                                                sizeof(search_buf), NULL, NULL);
                if (len > 0)
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN,
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_SEARCH_DOMAIN,
                                        len, search_buf);
        }
 
        if (iface->dhcpv4_router_cnt == 0)
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &iface->dhcpv4_local);
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_ROUTER, 4, &iface->dhcpv4_local);
        else
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER,
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_ROUTER,
                                4 * iface->dhcpv4_router_cnt, iface->dhcpv4_router);
 
 
        if (iface->dhcpv4_dns_cnt == 0) {
                if (iface->dns_service)
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER, 4, &iface->dhcpv4_local);
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_DNSSERVER, 4, &iface->dhcpv4_local);
        } else
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER,
+               dhcpv4_put(&reply, &cursor, DHCPV4_OPT_DNSSERVER,
                                4 * iface->dhcpv4_dns_cnt, iface->dhcpv4_dns);
 
        for (size_t opt = 0; a && opt < a->reqopts_len; opt++) {
                switch (a->reqopts[opt]) {
                case DHCPV4_OPT_NTPSERVER:
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NTPSERVER,
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_NTPSERVER,
                                   4 * iface->dhcpv4_ntp_cnt, iface->dhcpv4_ntp);
                        break;
 
@@ -860,13 +860,13 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
                                memcpy(&d4dnr->len, &d4dnr_len_be, sizeof(d4dnr_len_be));
                        }
 
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNR,
+                       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_DNR,
                                   dnrs_len, dnrs);
                        break;
                }
        }
 
-       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_END, 0, NULL);
+       dhcpv4_put(&reply, &cursor, DHCPV4_OPT_END, 0, NULL);
 
        struct sockaddr_in dest = *((struct sockaddr_in*)addr);
        if (req->giaddr.s_addr) {
@@ -915,7 +915,7 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
                }
        }
 
-       if (send_reply(&reply, PACKET_SIZE(&reply, cookie),
+       if (send_reply(&reply, PACKET_SIZE(&reply, cursor),
                       (struct sockaddr*)&dest, sizeof(dest), opaque) < 0)
                syslog(LOG_ERR, "Failed to send %s to %s - %s: %m",
                        dhcpv4_msg_to_string(msg),