Ticket #21225: patch-tcpkill.c.diff

tcpkill.c

@@ -39 +39 @@
 static void
 tcp_kill_cb(u_char *user, const struct pcap_pkthdr *pcap, const u_char *pkt)
 {
-        struct libnet_ip_hdr *ip;
+        struct libnet_ipv4_hdr *ip;
         struct libnet_tcp_hdr *tcp;
-        u_char ctext[64], buf[IP_H + TCP_H];
+        u_char ctext[64];
         u_int32_t seq, win;
-        int i, *sock, len;
+        int i, len;
+        libnet_t *l;
 
-        sock = (int *)user;
+        l = (libnet_t *)user;
         pkt += pcap_off;
         len = pcap->caplen - pcap_off;
 
-        ip = (struct libnet_ip_hdr *)pkt;
+        ip = (struct libnet_ipv4_hdr *)pkt;
         if (ip->ip_p != IPPROTO_TCP)
                 return;
         
@@ -57 +58 @@
         if (tcp->th_flags & (TH_SYN|TH_FIN|TH_RST))
                 return;
 
-        libnet_build_ip(TCP_H, 0, 0, 0, 64, IPPROTO_TCP,
-                        ip->ip_dst.s_addr, ip->ip_src.s_addr,
-                        NULL, 0, buf);
-
-        libnet_build_tcp(ntohs(tcp->th_dport), ntohs(tcp->th_sport),
-                         0, 0, TH_RST, 0, 0, NULL, 0, buf + IP_H);
-        
         seq = ntohl(tcp->th_ack);
         win = ntohs(tcp->th_win);
         
         snprintf(ctext, sizeof(ctext), "%s:%d > %s:%d:",
-                 libnet_host_lookup(ip->ip_src.s_addr, 0),
+                 libnet_addr2name4(ip->ip_src.s_addr, LIBNET_DONT_RESOLVE),
                  ntohs(tcp->th_sport),
-                 libnet_host_lookup(ip->ip_dst.s_addr, 0),
+                 libnet_addr2name4(ip->ip_dst.s_addr, LIBNET_DONT_RESOLVE),
                  ntohs(tcp->th_dport));
         
-        ip = (struct libnet_ip_hdr *)buf;
-        tcp = (struct libnet_tcp_hdr *)(ip + 1);
-        
         for (i = 0; i < Opt_severity; i++) {
-                ip->ip_id = libnet_get_prand(PRu16);
                 seq += (i * win);
-                tcp->th_seq = htonl(seq);
                 
-                libnet_do_checksum(buf, IPPROTO_TCP, TCP_H);
+                libnet_clear_packet(l);
+                
+                libnet_build_tcp(ntohs(tcp->th_dport), ntohs(tcp->th_sport),
+                                 seq, 0, TH_RST, 0, 0, 0, LIBNET_TCP_H, 
+                                 NULL, 0, l, 0);
+                
+                libnet_build_ipv4(LIBNET_IPV4_H + LIBNET_TCP_H, 0,
+                                  libnet_get_prand(LIBNET_PRu16), 0, 64,
+                                  IPPROTO_TCP, 0, ip->ip_dst.s_addr,
+                                  ip->ip_src.s_addr, NULL, 0, l, 0);
                 
-                if (libnet_write_ip(*sock, buf, sizeof(buf)) < 0)
-                        warn("write_ip");
+                if (libnet_write(l) < 0)
+                        warn("write");
                 
                 fprintf(stderr, "%s R %lu:%lu(0) win 0\n", ctext, seq, seq);
         }
@@ -95 +93 @@
 {
         extern char *optarg;
         extern int optind;
-        int c, sock;
+        int c;
         char *p, *intf, *filter, ebuf[PCAP_ERRBUF_SIZE];
+        char libnet_ebuf[LIBNET_ERRBUF_SIZE];
+        libnet_t *l;
         pcap_t *pd;
         
         intf = NULL;
@@ -136 +136 @@
         if ((pcap_off = pcap_dloff(pd)) < 0)
                 errx(1, "couldn't determine link layer offset");
         
-        if ((sock = libnet_open_raw_sock(IPPROTO_RAW)) == -1)
+        if ((l = libnet_init(LIBNET_RAW4, intf, libnet_ebuf)) == NULL)
                 errx(1, "couldn't initialize sending");
         
-        libnet_seed_prand();
+        libnet_seed_prand(l);
         
         warnx("listening on %s [%s]", intf, filter);
         
-        pcap_loop(pd, -1, tcp_kill_cb, (u_char *)&sock);
+        pcap_loop(pd, -1, tcp_kill_cb, (u_char *)l);
   
         /* NOTREACHED */