Initial commit after restructure

firewall/interception/nfqueue/nfqueue.c

@@ -0,0 +1,88 @@
+#include "nfqueue.h"
+#include "_cgo_export.h"
+
+
+int nfqueue_cb_new(struct nfq_q_handle *qh, struct nfgenmsg *nfmsg, struct nfq_data *nfa, void *data) {
+
+  struct nfqnl_msg_packet_hdr *ph = nfq_get_msg_packet_hdr(nfa);
+
+  if(ph == NULL) {
+    return 1;
+  }
+
+  int id =  ntohl(ph->packet_id);
+
+  unsigned char * payload;
+  unsigned char * saddr, * daddr;
+  uint16_t sport = 0,  dport = 0, checksum = 0;
+  uint32_t mark = nfq_get_nfmark(nfa);
+
+  int len = nfq_get_payload(nfa, &payload);
+
+  unsigned char * origpayload = payload;
+  int origlen = len;
+
+  if(len <  sizeof(struct iphdr)) {
+    return 0;
+  }
+
+  struct iphdr * ip = (struct iphdr *) payload;
+
+  if(ip->version == 4) {
+        uint32_t ipsz = (ip->ihl << 2);
+        if(len < ipsz) {
+            return 0;
+        }
+        len -= ipsz;
+        payload += ipsz;
+
+    saddr = (unsigned char *)&ip->saddr;
+    daddr = (unsigned char *)&ip->daddr;
+
+    if(ip->protocol == IPPROTO_TCP) {
+        if(len < sizeof(struct tcphdr)) {
+            return 0;
+        }
+      struct tcphdr *tcp = (struct tcphdr *) payload;
+      uint32_t tcpsz = (tcp->doff << 2);
+      if(len < tcpsz) {
+          return 0;
+      }
+      len -= tcpsz;
+      payload += tcpsz;
+
+      sport = ntohs(tcp->source);
+      dport = ntohs(tcp->dest);
+      checksum = ntohs(tcp->check);
+    } else if(ip->protocol == IPPROTO_UDP) {
+        if(len < sizeof(struct udphdr)) {
+            return 0;
+        }
+      struct udphdr *u = (struct udphdr *) payload;
+      len -= sizeof(struct udphdr);
+      payload += sizeof(struct udphdr);
+
+      sport = ntohs(u->source);
+      dport = ntohs(u->dest);
+      checksum = ntohs(u->check);
+    }
+  } else {
+    struct ipv6hdr *ip6 = (struct ipv6hdr*) payload;
+    saddr = (unsigned char *)&ip6->saddr;
+    daddr = (unsigned char *)&ip6->daddr;
+    //ipv6
+  }
+  //pass everything we can and let Go handle it, I'm not a big fan of C
+  uint32_t verdict = go_nfq_callback(id, ntohs(ph->hw_protocol), ph->hook, &mark, ip->version, ip->protocol,
+                  ip->tos, ip->ttl, saddr, daddr, sport, dport, checksum, origlen, origpayload, data);
+  return nfq_set_verdict2(qh, id, verdict, mark, 0, NULL);
+}
+
+void loop_for_packets(struct nfq_handle *h) {
+  int fd = nfq_fd(h);
+  char buf[65535] __attribute__ ((aligned));
+  int rv;
+  while ((rv = recv(fd, buf, sizeof(buf), 0)) && rv >= 0) {
+    nfq_handle_packet(h, buf, rv);
+  }
+}