Fix the return values of dhcp_packet_get and arp_packet_get.

This corrects a bug where stale dhcp packets would get reprocessed,
causing very bad behavior; an issue that was introduced in the
coroutine conversion.

src/arp.c

@@ -674,14 +674,14 @@ server_is_router:
     return ARPR_OK;
 }
 
-int arp_packet_get(struct client_state_t cs[static 1])
+bool arp_packet_get(struct client_state_t cs[static 1])
 {
     ssize_t r = 0;
     if (garp.reply_offset < sizeof garp.reply) {
         r = safe_read(cs->arpFd, (char *)&garp.reply + garp.reply_offset,
                       sizeof garp.reply - garp.reply_offset);
         if (r == 0)
-            return ARPP_NONE;
+            return false;
         if (r < 0) {
             log_error("%s: (%s) ARP response read failed: %s",
                       client_config.interface, __func__, strerror(errno));
@@ -690,13 +690,13 @@ int arp_packet_get(struct client_state_t cs[static 1])
             if (arp_open_fd(cs, cs->arp_is_defense) < 0)
                 suicide("%s: (%s) Failed to reopen ARP fd: %s",
                         client_config.interface, __func__, strerror(errno));
-            return ARPP_NONE;
+            return false;
         }
         garp.reply_offset += (size_t)r;
     }
 
     if (garp.reply_offset < ARP_MSG_SIZE)
-        return ARPP_NONE;
+        return false;
 
     // Emulate the BPF filters if they are not in use.
     if (!garp.using_bpf &&
@@ -704,9 +704,9 @@ int arp_packet_get(struct client_state_t cs[static 1])
          (cs->arp_is_defense &&
           !arp_validate_bpf_defense(cs, &garp.reply)))) {
         arp_reply_clear();
-        return ARPP_NONE;
+        return false;
     }
-    return ARPP_HAVE;
+    return true;
 }
 
 // XXX: Move into client_state

src/arp.h

@@ -104,7 +104,7 @@ struct arp_data {
 
 void arp_reply_clear(void);
 
-int arp_packet_get(struct client_state_t cs[static 1]);
+bool arp_packet_get(struct client_state_t cs[static 1]);
 
 void set_arp_relentless_def(bool v);
 void arp_reset_send_stats(void);
@@ -134,11 +134,6 @@ int arp_gw_check_timeout(struct client_state_t cs[static 1], long long nowts);
 #define ARPR_FAIL -2
 
 
-// There is no new packet.
-#define ARPP_NONE 0
-// We have a pending packet.
-#define ARPP_HAVE 1
-
 long long arp_get_wake_ts(void);
 
 #endif /* ARP_H_ */

src/dhcp.c

@@ -380,13 +380,13 @@ static int validate_dhcp_packet(struct client_state_t cs[static 1],
     return 1;
 }
 
-int dhcp_packet_get(struct client_state_t cs[static 1],
+bool dhcp_packet_get(struct client_state_t cs[static 1],
                      struct dhcpmsg packet[static 1],
                      uint8_t msgtype[static 1],
                      uint32_t srcaddr[static 1])
 {
     if (cs->listenFd < 0)
-        return -1;
+        return false;
     ssize_t r = get_raw_packet(cs, packet, srcaddr);
     if (r < 0) {
         // Not a transient issue handled by packet collection functions.
@@ -396,11 +396,11 @@ int dhcp_packet_get(struct client_state_t cs[static 1],
             stop_dhcp_listen(cs);
             start_dhcp_listen(cs);
         }
-        return -1;
+        return false;
     }
     if (!validate_dhcp_packet(cs, (size_t)r, packet, msgtype))
-        return -1;
+        return false;
-    return 0;
+    return true;
 }
 
 // Initialize a DHCP client packet that will be sent to a server

src/dhcp.h

@@ -83,7 +83,7 @@ struct udp_dhcp_packet {
 
 void start_dhcp_listen(struct client_state_t cs[static 1]);
 void stop_dhcp_listen(struct client_state_t cs[static 1]);
-int dhcp_packet_get(struct client_state_t cs[static 1],
+bool dhcp_packet_get(struct client_state_t cs[static 1],
                      struct dhcpmsg packet[static 1],
                      uint8_t msgtype[static 1],
                      uint32_t srcaddr[static 1]);

src/ndhc.c

@@ -292,10 +292,10 @@ static void do_ndhc_work(void)
             else
                 suicide("epoll_wait failed");
         }
-        int sev_dhcp = -1;
+        bool sev_dhcp = false;
         uint32_t dhcp_srcaddr;
         uint8_t dhcp_msgtype;
-        int sev_arp = ARPP_NONE;
+        bool sev_arp = false;
         int sev_nl = IFS_NONE;
         int sev_rfk = RFK_NONE;
         int sev_signal = SIGNAL_NONE;

src/state.c

@@ -437,8 +437,8 @@ static int ifup_action(struct client_state_t cs[static 1])
 
 // XXX: Should be re-entrant so as to handle multiple servers.
 int dhcp_handle(struct client_state_t cs[static 1], long long nowts,
-                int sev_dhcp, struct dhcpmsg dhcp_packet[static 1],
+                bool sev_dhcp, struct dhcpmsg dhcp_packet[static 1],
-                uint8_t dhcp_msgtype, uint32_t dhcp_srcaddr, int sev_arp,
+                uint8_t dhcp_msgtype, uint32_t dhcp_srcaddr, bool sev_arp,
                 bool force_fingerprint, bool dhcp_timeout, bool arp_timeout,
                 int sev_signal)
 {

src/state.h

@@ -41,8 +41,8 @@ enum {
 };
 
 int dhcp_handle(struct client_state_t cs[static 1], long long nowts,
-                int sev_dhcp, struct dhcpmsg dhcp_packet[static 1],
+                bool sev_dhcp, struct dhcpmsg dhcp_packet[static 1],
-                uint8_t dhcp_msgtype, uint32_t dhcp_srcaddr, int sev_arp,
+                uint8_t dhcp_msgtype, uint32_t dhcp_srcaddr, bool sev_arp,
                 bool force_fingerprint, bool dhcp_timeout, bool arp_timeout,
                 int sev_signal);