mirror of
https://github.com/bol-van/zapret.git
synced 2026-01-04 15:48:47 +03:00
nfqws: udp protocol desync
This commit is contained in:
bol-van
904
nfq/darkmagic.c
904
nfq/darkmagic.c
@@ -67,9 +67,9 @@ static void fill_tcphdr(
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uint8_t t=0;
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memset(tcp,0,sizeof(*tcp));
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tcp->th_sport = nsport;
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tcp->th_dport = ndport;
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if (fooling & TCP_FOOL_BADSEQ)
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tcp->th_sport = nsport;
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tcp->th_dport = ndport;
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if (fooling & FOOL_BADSEQ)
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{
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tcp->th_seq = net32_add(nseq,badseq_increment);
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tcp->th_ack = net32_add(nack_seq,badseq_ack_increment);
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@@ -82,7 +82,7 @@ static void fill_tcphdr(
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tcp->th_off = 5;
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*((uint8_t*)tcp+13)= tcp_flags;
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tcp->th_win = nwsize;
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if (fooling & TCP_FOOL_MD5SIG)
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if (fooling & FOOL_MD5SIG)
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{
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tcpopt[0] = 19; // kind
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tcpopt[1] = 18; // len
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@@ -92,13 +92,13 @@ static void fill_tcphdr(
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*(uint32_t*)(tcpopt+14)=random();
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t=18;
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}
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if (timestamps || (fooling & TCP_FOOL_TS))
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if (timestamps || (fooling & FOOL_TS))
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{
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tcpopt[t] = 8; // kind
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tcpopt[t+1] = 10; // len
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// forge only TSecr if orig timestamp is present
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*(uint32_t*)(tcpopt+t+2) = timestamps ? timestamps[0] : -1;
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*(uint32_t*)(tcpopt+t+6) = (timestamps && !(fooling & TCP_FOOL_TS)) ? timestamps[1] : -1;
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*(uint32_t*)(tcpopt+t+6) = (timestamps && !(fooling & FOOL_TS)) ? timestamps[1] : -1;
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t+=10;
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}
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if (scale_factor!=SCALE_NONE)
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@@ -109,16 +109,518 @@ static void fill_tcphdr(
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}
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while (t&3) tcpopt[t++]=1; // noop
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tcp->th_off += t>>2;
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tcp->th_sum = 0;
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}
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static uint16_t tcpopt_len(uint8_t fooling, const uint32_t *timestamps, uint8_t scale_factor)
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{
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uint16_t t=0;
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if (fooling & TCP_FOOL_MD5SIG) t=18;
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if ((fooling & TCP_FOOL_TS) || timestamps) t+=10;
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if (fooling & FOOL_MD5SIG) t=18;
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if ((fooling & FOOL_TS) || timestamps) t+=10;
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if (scale_factor!=SCALE_NONE) t+=3;
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return (t+3)&~3;
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}
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// n prefix (nsport, nwsize) means network byte order
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static void fill_udphdr(struct udphdr *udp, uint16_t nsport, uint16_t ndport, uint16_t len_payload)
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{
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udp->uh_sport = nsport;
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udp->uh_dport = ndport;
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udp->uh_ulen = htons(len_payload+sizeof(struct udphdr));
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udp->uh_sum = 0;
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}
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static void fill_iphdr(struct ip *ip, const struct in_addr *src, const struct in_addr *dst, uint16_t pktlen, uint8_t proto, uint8_t ttl)
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{
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ip->ip_off = 0;
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ip->ip_v = 4;
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ip->ip_hl = 5;
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ip->ip_len = htons(pktlen);
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ip->ip_id = 0;
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ip->ip_ttl = ttl;
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ip->ip_p = proto;
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ip->ip_src = *src;
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ip->ip_dst = *dst;
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}
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static void fill_ip6hdr(struct ip6_hdr *ip6, const struct in6_addr *src, const struct in6_addr *dst, uint16_t payloadlen, uint8_t proto, uint8_t ttl)
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{
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ip6->ip6_ctlun.ip6_un1.ip6_un1_flow = htonl(0x60000000);
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ip6->ip6_ctlun.ip6_un1.ip6_un1_plen = htons(payloadlen);
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ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt = proto;
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ip6->ip6_ctlun.ip6_un1.ip6_un1_hlim = ttl;
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ip6->ip6_src = *src;
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ip6->ip6_dst = *dst;
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}
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bool prepare_tcp_segment4(
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const struct sockaddr_in *src, const struct sockaddr_in *dst,
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uint8_t tcp_flags,
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uint32_t nseq, uint32_t nack_seq,
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uint16_t nwsize,
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uint8_t scale_factor,
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uint32_t *timestamps,
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uint8_t ttl,
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uint8_t fooling,
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uint32_t badseq_increment,
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uint32_t badseq_ack_increment,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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uint16_t tcpoptlen = tcpopt_len(fooling,timestamps,scale_factor);
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uint16_t ip_payload_len = sizeof(struct tcphdr) + tcpoptlen + len;
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uint16_t pktlen = sizeof(struct ip) + ip_payload_len;
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if (pktlen>*buflen) return false;
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struct ip *ip = (struct ip*)buf;
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struct tcphdr *tcp = (struct tcphdr*)(ip+1);
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uint8_t *payload = (uint8_t*)(tcp+1)+tcpoptlen;
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fill_iphdr(ip, &src->sin_addr, &dst->sin_addr, pktlen, IPPROTO_TCP, ttl);
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fill_tcphdr(tcp,fooling,tcp_flags,nseq,nack_seq,src->sin_port,dst->sin_port,nwsize,scale_factor,timestamps,badseq_increment,badseq_ack_increment);
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memcpy(payload,data,len);
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tcp4_fix_checksum(tcp,ip_payload_len,&ip->ip_src,&ip->ip_dst);
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if (fooling & FOOL_BADSUM) tcp->th_sum^=htons(0xBEAF);
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*buflen = pktlen;
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return true;
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}
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bool prepare_tcp_segment6(
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const struct sockaddr_in6 *src, const struct sockaddr_in6 *dst,
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uint8_t tcp_flags,
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uint32_t nseq, uint32_t nack_seq,
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uint16_t nwsize,
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uint8_t scale_factor,
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uint32_t *timestamps,
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uint8_t ttl,
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uint8_t fooling,
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uint32_t badseq_increment,
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uint32_t badseq_ack_increment,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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uint16_t tcpoptlen = tcpopt_len(fooling,timestamps,scale_factor);
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uint16_t ip_payload_len = sizeof(struct tcphdr) + tcpoptlen + len;
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uint16_t pktlen = sizeof(struct ip6_hdr) + ip_payload_len;
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if (pktlen>*buflen) return false;
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struct ip6_hdr *ip6 = (struct ip6_hdr*)buf;
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struct tcphdr *tcp = (struct tcphdr*)(ip6+1);
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uint8_t *payload = (uint8_t*)(tcp+1)+tcpoptlen;
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fill_ip6hdr(ip6, &src->sin6_addr, &dst->sin6_addr, ip_payload_len, IPPROTO_TCP, ttl);
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fill_tcphdr(tcp,fooling,tcp_flags,nseq,nack_seq,src->sin6_port,dst->sin6_port,nwsize,scale_factor,timestamps,badseq_increment,badseq_ack_increment);
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memcpy(payload,data,len);
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tcp6_fix_checksum(tcp,ip_payload_len,&ip6->ip6_src,&ip6->ip6_dst);
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if (fooling & FOOL_BADSUM) tcp->th_sum^=htons(0xBEAF);
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*buflen = pktlen;
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return true;
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}
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bool prepare_tcp_segment(
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const struct sockaddr *src, const struct sockaddr *dst,
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uint8_t tcp_flags,
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uint32_t nseq, uint32_t nack_seq,
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uint16_t nwsize,
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uint8_t scale_factor,
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uint32_t *timestamps,
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uint8_t ttl,
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uint8_t fooling,
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uint32_t badseq_increment,
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uint32_t badseq_ack_increment,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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return (src->sa_family==AF_INET && dst->sa_family==AF_INET) ?
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prepare_tcp_segment4((struct sockaddr_in *)src,(struct sockaddr_in *)dst,tcp_flags,nseq,nack_seq,nwsize,scale_factor,timestamps,ttl,fooling,badseq_increment,badseq_ack_increment,data,len,buf,buflen) :
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(src->sa_family==AF_INET6 && dst->sa_family==AF_INET6) ?
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prepare_tcp_segment6((struct sockaddr_in6 *)src,(struct sockaddr_in6 *)dst,tcp_flags,nseq,nack_seq,nwsize,scale_factor,timestamps,ttl,fooling,badseq_increment,badseq_ack_increment,data,len,buf,buflen) :
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false;
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}
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bool prepare_udp_segment4(
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const struct sockaddr_in *src, const struct sockaddr_in *dst,
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uint8_t ttl,
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uint8_t fooling,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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uint16_t ip_payload_len = sizeof(struct udphdr) + len;
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uint16_t pktlen = sizeof(struct ip) + ip_payload_len;
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if (pktlen>*buflen) return false;
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struct ip *ip = (struct ip*)buf;
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struct udphdr *udp = (struct udphdr*)(ip+1);
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uint8_t *payload = (uint8_t*)(udp+1);
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fill_iphdr(ip, &src->sin_addr, &dst->sin_addr, pktlen, IPPROTO_UDP, ttl);
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fill_udphdr(udp, src->sin_port, dst->sin_port, len);
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memcpy(payload,data,len);
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udp4_fix_checksum(udp,ip_payload_len,&ip->ip_src,&ip->ip_dst);
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if (fooling & FOOL_BADSUM) udp->uh_sum^=htons(0xBEAF);
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*buflen = pktlen;
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return true;
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}
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bool prepare_udp_segment6(
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const struct sockaddr_in6 *src, const struct sockaddr_in6 *dst,
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uint8_t ttl,
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uint8_t fooling,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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uint16_t ip_payload_len = sizeof(struct udphdr) + len;
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uint16_t pktlen = sizeof(struct ip6_hdr) + ip_payload_len;
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if (pktlen>*buflen) return false;
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struct ip6_hdr *ip6 = (struct ip6_hdr*)buf;
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struct udphdr *udp = (struct udphdr*)(ip6+1);
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uint8_t *payload = (uint8_t*)(udp+1);
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fill_ip6hdr(ip6, &src->sin6_addr, &dst->sin6_addr, ip_payload_len, IPPROTO_UDP, ttl);
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fill_udphdr(udp, src->sin6_port, dst->sin6_port, len);
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memcpy(payload,data,len);
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udp6_fix_checksum(udp,ip_payload_len,&ip6->ip6_src,&ip6->ip6_dst);
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if (fooling & FOOL_BADSUM) udp->uh_sum^=htons(0xBEAF);
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*buflen = pktlen;
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return true;
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}
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bool prepare_udp_segment(
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const struct sockaddr *src, const struct sockaddr *dst,
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uint8_t ttl,
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uint8_t fooling,
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const void *data, uint16_t len,
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uint8_t *buf, size_t *buflen)
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{
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return (src->sa_family==AF_INET && dst->sa_family==AF_INET) ?
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prepare_udp_segment4((struct sockaddr_in *)src,(struct sockaddr_in *)dst,ttl,fooling,data,len,buf,buflen) :
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(src->sa_family==AF_INET6 && dst->sa_family==AF_INET6) ?
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prepare_udp_segment6((struct sockaddr_in6 *)src,(struct sockaddr_in6 *)dst,ttl,fooling,data,len,buf,buflen) :
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false;
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}
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void extract_ports(const struct tcphdr *tcphdr, const struct udphdr *udphdr, uint8_t *proto, uint16_t *sport, uint16_t *dport)
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{
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if (sport) *sport = htons(tcphdr ? tcphdr->th_sport : udphdr ? udphdr->uh_sport : 0);
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if (dport) *dport = htons(tcphdr ? tcphdr->th_dport : udphdr ? udphdr->uh_dport : 0);
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if (proto) *proto = tcphdr ? IPPROTO_TCP : udphdr ? IPPROTO_UDP : -1;
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}
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void extract_endpoints(const struct ip *ip,const struct ip6_hdr *ip6hdr,const struct tcphdr *tcphdr,const struct udphdr *udphdr, struct sockaddr_storage *src, struct sockaddr_storage *dst)
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{
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if (ip)
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{
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struct sockaddr_in *si;
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if (dst)
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{
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si = (struct sockaddr_in*)dst;
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si->sin_family = AF_INET;
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si->sin_port = tcphdr ? tcphdr->th_dport : udphdr ? udphdr->uh_dport : 0;
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si->sin_addr = ip->ip_dst;
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}
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if (src)
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{
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si = (struct sockaddr_in*)src;
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si->sin_family = AF_INET;
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si->sin_port = tcphdr ? tcphdr->th_sport : udphdr ? udphdr->uh_sport : 0;
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si->sin_addr = ip->ip_src;
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}
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}
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else if (ip6hdr)
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{
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struct sockaddr_in6 *si;
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if (dst)
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{
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si = (struct sockaddr_in6*)dst;
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si->sin6_family = AF_INET6;
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si->sin6_port = tcphdr ? tcphdr->th_dport : udphdr ? udphdr->uh_dport : 0;
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si->sin6_addr = ip6hdr->ip6_dst;
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si->sin6_flowinfo = 0;
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si->sin6_scope_id = 0;
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}
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if (src)
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{
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si = (struct sockaddr_in6*)src;
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si->sin6_family = AF_INET6;
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si->sin6_port = tcphdr ? tcphdr->th_sport : udphdr ? udphdr->uh_sport : 0;
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si->sin6_addr = ip6hdr->ip6_src;
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si->sin6_flowinfo = 0;
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si->sin6_scope_id = 0;
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}
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}
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}
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const char *proto_name(uint8_t proto)
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{
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switch(proto)
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{
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case IPPROTO_TCP:
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return "tcp";
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case IPPROTO_UDP:
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return "udp";
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case IPPROTO_ICMP:
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return "icmp";
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case IPPROTO_IGMP:
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return "igmp";
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case IPPROTO_ESP:
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return "esp";
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case IPPROTO_AH:
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return "ah";
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case IPPROTO_IPV6:
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return "6in4";
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case IPPROTO_IPIP:
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return "4in4";
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case IPPROTO_GRE:
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return "gre";
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#ifdef IPPROTO_SCTP
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case IPPROTO_SCTP:
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return "sctp";
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#endif
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default:
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return NULL;
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}
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}
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static void str_proto_name(char *s, size_t s_len, uint8_t proto)
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{
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const char *name = proto_name(proto);
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if (name)
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snprintf(s,s_len,"%s",name);
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else
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snprintf(s,s_len,"%u",proto);
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}
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uint16_t family_from_proto(uint8_t l3proto)
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{
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switch(l3proto)
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{
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case IPPROTO_IP: return AF_INET;
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case IPPROTO_IPV6: return AF_INET6;
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default: return -1;
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}
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}
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static void str_srcdst_ip(char *s, size_t s_len, const void *saddr,const void *daddr)
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{
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char s_ip[16],d_ip[16];
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*s_ip=*d_ip=0;
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inet_ntop(AF_INET, saddr, s_ip, sizeof(s_ip));
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inet_ntop(AF_INET, daddr, d_ip, sizeof(d_ip));
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snprintf(s,s_len,"%s => %s",s_ip,d_ip);
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}
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static void str_ip(char *s, size_t s_len, const struct ip *ip)
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{
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char ss[35],s_proto[16];
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str_srcdst_ip(ss,sizeof(ss),&ip->ip_src,&ip->ip_dst);
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str_proto_name(s_proto,sizeof(s_proto),ip->ip_p);
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snprintf(s,s_len,"%s proto=%s",ss,s_proto);
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}
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void print_ip(const struct ip *ip)
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{
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char s[64];
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str_ip(s,sizeof(s),ip);
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printf("%s",s);
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}
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static void str_srcdst_ip6(char *s, size_t s_len, const void *saddr,const void *daddr)
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{
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char s_ip[40],d_ip[40];
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*s_ip=*d_ip=0;
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inet_ntop(AF_INET6, saddr, s_ip, sizeof(s_ip));
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inet_ntop(AF_INET6, daddr, d_ip, sizeof(d_ip));
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snprintf(s,s_len,"%s => %s",s_ip,d_ip);
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}
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static void str_ip6hdr(char *s, size_t s_len, const struct ip6_hdr *ip6hdr, uint8_t proto)
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{
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char ss[83],s_proto[16];
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str_srcdst_ip6(ss,sizeof(ss),&ip6hdr->ip6_src,&ip6hdr->ip6_dst);
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str_proto_name(s_proto,sizeof(s_proto),proto);
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snprintf(s,s_len,"%s proto=%s",ss,s_proto);
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}
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void print_ip6hdr(const struct ip6_hdr *ip6hdr, uint8_t proto)
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{
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char s[128];
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str_ip6hdr(s,sizeof(s),ip6hdr,proto);
|
||||
printf("%s",s);
|
||||
}
|
||||
static void str_tcphdr(char *s, size_t s_len, const struct tcphdr *tcphdr)
|
||||
{
|
||||
char flags[7],*f=flags;
|
||||
if (tcphdr->th_flags & TH_SYN) *f++='S';
|
||||
if (tcphdr->th_flags & TH_ACK) *f++='A';
|
||||
if (tcphdr->th_flags & TH_RST) *f++='R';
|
||||
if (tcphdr->th_flags & TH_FIN) *f++='F';
|
||||
if (tcphdr->th_flags & TH_PUSH) *f++='P';
|
||||
if (tcphdr->th_flags & TH_URG) *f++='U';
|
||||
*f=0;
|
||||
snprintf(s,s_len,"sport=%u dport=%u flags=%s seq=%u ack_seq=%u",htons(tcphdr->th_sport),htons(tcphdr->th_dport),flags,htonl(tcphdr->th_seq),htonl(tcphdr->th_ack));
|
||||
}
|
||||
void print_tcphdr(const struct tcphdr *tcphdr)
|
||||
{
|
||||
char s[80];
|
||||
str_tcphdr(s,sizeof(s),tcphdr);
|
||||
printf("%s",s);
|
||||
}
|
||||
static void str_udphdr(char *s, size_t s_len, const struct udphdr *udphdr)
|
||||
{
|
||||
snprintf(s,s_len,"sport=%u dport=%u",htons(udphdr->uh_sport),htons(udphdr->uh_dport));
|
||||
}
|
||||
void print_udphdr(const struct udphdr *udphdr)
|
||||
{
|
||||
char s[30];
|
||||
str_udphdr(s,sizeof(s),udphdr);
|
||||
printf("%s",s);
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
bool proto_check_ipv4(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 20 && (data[0] & 0xF0) == 0x40 &&
|
||||
len >= ((data[0] & 0x0F) << 2);
|
||||
}
|
||||
// move to transport protocol
|
||||
void proto_skip_ipv4(uint8_t **data, size_t *len)
|
||||
{
|
||||
size_t l;
|
||||
|
||||
l = (**data & 0x0F) << 2;
|
||||
*data += l;
|
||||
*len -= l;
|
||||
}
|
||||
bool proto_check_tcp(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 20 && len >= ((data[12] & 0xF0) >> 2);
|
||||
}
|
||||
void proto_skip_tcp(uint8_t **data, size_t *len)
|
||||
{
|
||||
size_t l;
|
||||
l = ((*data)[12] & 0xF0) >> 2;
|
||||
*data += l;
|
||||
*len -= l;
|
||||
}
|
||||
bool proto_check_udp(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 8 && len>=(data[4]<<8 | data[5]);
|
||||
}
|
||||
void proto_skip_udp(uint8_t **data, size_t *len)
|
||||
{
|
||||
*data += 8;
|
||||
*len -= 8;
|
||||
}
|
||||
|
||||
bool proto_check_ipv6(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 40 && (data[0] & 0xF0) == 0x60 &&
|
||||
(len - 40) >= htons(*(uint16_t*)(data + 4)); // payload length
|
||||
}
|
||||
// move to transport protocol
|
||||
// proto_type = 0 => error
|
||||
void proto_skip_ipv6(uint8_t **data, size_t *len, uint8_t *proto_type)
|
||||
{
|
||||
size_t hdrlen;
|
||||
uint8_t HeaderType;
|
||||
|
||||
if (proto_type) *proto_type = 0; // put error in advance
|
||||
|
||||
HeaderType = (*data)[6]; // NextHeader field
|
||||
*data += 40; *len -= 40; // skip ipv6 base header
|
||||
while (*len > 0) // need at least one byte for NextHeader field
|
||||
{
|
||||
switch (HeaderType)
|
||||
{
|
||||
case 0: // Hop-by-Hop Options
|
||||
case 43: // routing
|
||||
case 51: // authentication
|
||||
case 60: // Destination Options
|
||||
case 135: // mobility
|
||||
case 139: // Host Identity Protocol Version v2
|
||||
case 140: // Shim6
|
||||
if (*len < 2) return; // error
|
||||
hdrlen = 8 + ((*data)[1] << 3);
|
||||
break;
|
||||
case 44: // fragment. length fixed to 8, hdrlen field defined as reserved
|
||||
hdrlen = 8;
|
||||
break;
|
||||
case 59: // no next header
|
||||
return; // error
|
||||
default:
|
||||
// we found some meaningful payload. it can be tcp, udp, icmp or some another exotic shit
|
||||
if (proto_type) *proto_type = HeaderType;
|
||||
return;
|
||||
}
|
||||
if (*len < hdrlen) return; // error
|
||||
HeaderType = **data;
|
||||
// advance to the next header location
|
||||
*len -= hdrlen;
|
||||
*data += hdrlen;
|
||||
}
|
||||
// we have garbage
|
||||
}
|
||||
|
||||
bool tcp_synack_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == (TH_ACK|TH_SYN));
|
||||
}
|
||||
bool tcp_syn_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == TH_SYN);
|
||||
}
|
||||
bool tcp_ack_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == TH_ACK);
|
||||
}
|
||||
|
||||
void tcp_rewrite_wscale(struct tcphdr *tcp, uint8_t scale_factor)
|
||||
{
|
||||
uint8_t *scale,scale_factor_old;
|
||||
|
||||
if (scale_factor!=SCALE_NONE)
|
||||
{
|
||||
scale = tcp_find_option(tcp,3); // tcp option 3 - scale factor
|
||||
if (scale && scale[1]==3) // length should be 3
|
||||
{
|
||||
scale_factor_old=scale[2];
|
||||
// do not allow increasing scale factor
|
||||
if (scale_factor>=scale_factor_old)
|
||||
DLOG("Scale factor %u unchanged\n", scale_factor_old)
|
||||
else
|
||||
{
|
||||
scale[2]=scale_factor;
|
||||
DLOG("Scale factor change %u => %u\n", scale_factor_old, scale_factor)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
// scale_factor=SCALE_NONE - do not change
|
||||
void tcp_rewrite_winsize(struct tcphdr *tcp, uint16_t winsize, uint8_t scale_factor)
|
||||
{
|
||||
uint16_t winsize_old;
|
||||
|
||||
winsize_old = htons(tcp->th_win); // << scale_factor;
|
||||
tcp->th_win = htons(winsize);
|
||||
DLOG("Window size change %u => %u\n", winsize_old, winsize)
|
||||
|
||||
tcp_rewrite_wscale(tcp, scale_factor);
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
static int rawsend_sock4=-1, rawsend_sock6=-1;
|
||||
static void rawsend_clean_sock(int *sock)
|
||||
{
|
||||
@@ -288,7 +790,7 @@ bool rawsend(const struct sockaddr* dst,uint32_t fwmark,const void *data,size_t
|
||||
// BSD ipv6 raw socks are limited. cannot pass the whole packet with ip6 header.
|
||||
struct sockaddr_storage sa_src;
|
||||
int v;
|
||||
extract_endpoints(NULL,(struct ip6_hdr *)data,NULL, &sa_src, NULL);
|
||||
extract_endpoints(NULL,(struct ip6_hdr *)data,NULL,NULL, &sa_src, NULL);
|
||||
v = ((struct ip6_hdr *)data)->ip6_ctlun.ip6_un1.ip6_un1_hlim;
|
||||
if (setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &v, sizeof(v)) == -1)
|
||||
perror("rawsend: setsockopt(IPV6_HOPLIMIT)");
|
||||
@@ -316,7 +818,7 @@ bool rawsend(const struct sockaddr* dst,uint32_t fwmark,const void *data,size_t
|
||||
#endif
|
||||
|
||||
#if defined(__FreeBSD__) && __FreeBSD__<=10
|
||||
// old FreeBSD requires some fields in the host byte order
|
||||
// old FreeBSD requires some fields in host byte order
|
||||
if (dst->sa_family==AF_INET && len>=sizeof(struct ip))
|
||||
{
|
||||
((struct ip*)data)->ip_len = htons(((struct ip*)data)->ip_len);
|
||||
@@ -340,385 +842,3 @@ bool rawsend(const struct sockaddr* dst,uint32_t fwmark,const void *data,size_t
|
||||
}
|
||||
return true;
|
||||
}
|
||||
bool prepare_tcp_segment4(
|
||||
const struct sockaddr_in *src, const struct sockaddr_in *dst,
|
||||
uint8_t tcp_flags,
|
||||
uint32_t nseq, uint32_t nack_seq,
|
||||
uint16_t nwsize,
|
||||
uint8_t scale_factor,
|
||||
uint32_t *timestamps,
|
||||
uint8_t ttl,
|
||||
uint8_t fooling,
|
||||
uint32_t badseq_increment,
|
||||
uint32_t badseq_ack_increment,
|
||||
const void *data, uint16_t len,
|
||||
uint8_t *buf, size_t *buflen)
|
||||
{
|
||||
uint16_t tcpoptlen = tcpopt_len(fooling,timestamps, scale_factor);
|
||||
uint16_t pktlen = sizeof(struct ip) + sizeof(struct tcphdr) + tcpoptlen + len;
|
||||
if (pktlen>*buflen)
|
||||
{
|
||||
fprintf(stderr,"prepare_tcp_segment : packet len cannot exceed %zu\n",*buflen);
|
||||
return false;
|
||||
}
|
||||
|
||||
struct ip *ip = (struct ip*) buf;
|
||||
struct tcphdr *tcp = (struct tcphdr*) (ip+1);
|
||||
|
||||
ip->ip_off = 0;
|
||||
ip->ip_v = 4;
|
||||
ip->ip_hl = 5;
|
||||
ip->ip_len = htons(pktlen);
|
||||
ip->ip_id = 0;
|
||||
ip->ip_ttl = ttl;
|
||||
ip->ip_p = IPPROTO_TCP;
|
||||
ip->ip_src = src->sin_addr;
|
||||
ip->ip_dst = dst->sin_addr;
|
||||
|
||||
fill_tcphdr(tcp,fooling,tcp_flags,nseq,nack_seq,src->sin_port,dst->sin_port,nwsize,scale_factor,timestamps,badseq_increment,badseq_ack_increment);
|
||||
|
||||
memcpy((char*)tcp+sizeof(struct tcphdr)+tcpoptlen,data,len);
|
||||
tcp4_fix_checksum(tcp,sizeof(struct tcphdr)+tcpoptlen+len,&ip->ip_src,&ip->ip_dst);
|
||||
if (fooling & TCP_FOOL_BADSUM) tcp->th_sum^=0xBEAF;
|
||||
|
||||
*buflen = pktlen;
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
bool prepare_tcp_segment6(
|
||||
const struct sockaddr_in6 *src, const struct sockaddr_in6 *dst,
|
||||
uint8_t tcp_flags,
|
||||
uint32_t nseq, uint32_t nack_seq,
|
||||
uint16_t nwsize,
|
||||
uint8_t scale_factor,
|
||||
uint32_t *timestamps,
|
||||
uint8_t ttl,
|
||||
uint8_t fooling,
|
||||
uint32_t badseq_increment,
|
||||
uint32_t badseq_ack_increment,
|
||||
const void *data, uint16_t len,
|
||||
uint8_t *buf, size_t *buflen)
|
||||
{
|
||||
uint16_t tcpoptlen = tcpopt_len(fooling,timestamps, scale_factor);
|
||||
uint16_t payloadlen = sizeof(struct tcphdr) + tcpoptlen + len;
|
||||
uint16_t pktlen = sizeof(struct ip6_hdr) + payloadlen;
|
||||
if (pktlen>*buflen)
|
||||
{
|
||||
fprintf(stderr,"prepare_tcp_segment : packet len cannot exceed %zu\n",*buflen);
|
||||
return false;
|
||||
}
|
||||
|
||||
struct ip6_hdr *ip6 = (struct ip6_hdr*) buf;
|
||||
struct tcphdr *tcp = (struct tcphdr*) (ip6+1);
|
||||
|
||||
ip6->ip6_ctlun.ip6_un1.ip6_un1_flow = htonl(0x60000000);
|
||||
ip6->ip6_ctlun.ip6_un1.ip6_un1_plen = htons(payloadlen);
|
||||
ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt = IPPROTO_TCP;
|
||||
ip6->ip6_ctlun.ip6_un1.ip6_un1_hlim = ttl;
|
||||
ip6->ip6_src = src->sin6_addr;
|
||||
ip6->ip6_dst = dst->sin6_addr;
|
||||
|
||||
fill_tcphdr(tcp,fooling,tcp_flags,nseq,nack_seq,src->sin6_port,dst->sin6_port,nwsize,scale_factor,timestamps,badseq_increment,badseq_ack_increment);
|
||||
|
||||
memcpy((char*)tcp+sizeof(struct tcphdr)+tcpoptlen,data,len);
|
||||
tcp6_fix_checksum(tcp,sizeof(struct tcphdr)+tcpoptlen+len,&ip6->ip6_src,&ip6->ip6_dst);
|
||||
if (fooling & TCP_FOOL_BADSUM) tcp->th_sum^=0xBEAF;
|
||||
|
||||
*buflen = pktlen;
|
||||
return true;
|
||||
}
|
||||
|
||||
bool prepare_tcp_segment(
|
||||
const struct sockaddr *src, const struct sockaddr *dst,
|
||||
uint8_t tcp_flags,
|
||||
uint32_t nseq, uint32_t nack_seq,
|
||||
uint16_t nwsize,
|
||||
uint8_t scale_factor,
|
||||
uint32_t *timestamps,
|
||||
uint8_t ttl,
|
||||
uint8_t fooling,
|
||||
uint32_t badseq_increment,
|
||||
uint32_t badseq_ack_increment,
|
||||
const void *data, uint16_t len,
|
||||
uint8_t *buf, size_t *buflen)
|
||||
{
|
||||
return (src->sa_family==AF_INET && dst->sa_family==AF_INET) ?
|
||||
prepare_tcp_segment4((struct sockaddr_in *)src,(struct sockaddr_in *)dst,tcp_flags,nseq,nack_seq,nwsize,scale_factor,timestamps,ttl,fooling,badseq_increment,badseq_ack_increment,data,len,buf,buflen) :
|
||||
(src->sa_family==AF_INET6 && dst->sa_family==AF_INET6) ?
|
||||
prepare_tcp_segment6((struct sockaddr_in6 *)src,(struct sockaddr_in6 *)dst,tcp_flags,nseq,nack_seq,nwsize,scale_factor,timestamps,ttl,fooling,badseq_increment,badseq_ack_increment,data,len,buf,buflen) :
|
||||
false;
|
||||
}
|
||||
|
||||
|
||||
void extract_endpoints(const struct ip *ip,const struct ip6_hdr *ip6hdr,const struct tcphdr *tcphdr, struct sockaddr_storage *src, struct sockaddr_storage *dst)
|
||||
{
|
||||
if (ip)
|
||||
{
|
||||
struct sockaddr_in *si;
|
||||
|
||||
if (dst)
|
||||
{
|
||||
si = (struct sockaddr_in*)dst;
|
||||
si->sin_family = AF_INET;
|
||||
si->sin_port = tcphdr ? tcphdr->th_dport : 0;
|
||||
si->sin_addr = ip->ip_dst;
|
||||
}
|
||||
|
||||
if (src)
|
||||
{
|
||||
si = (struct sockaddr_in*)src;
|
||||
si->sin_family = AF_INET;
|
||||
si->sin_port = tcphdr ? tcphdr->th_sport : 0;
|
||||
si->sin_addr = ip->ip_src;
|
||||
}
|
||||
}
|
||||
else if (ip6hdr)
|
||||
{
|
||||
struct sockaddr_in6 *si;
|
||||
|
||||
if (dst)
|
||||
{
|
||||
si = (struct sockaddr_in6*)dst;
|
||||
si->sin6_family = AF_INET6;
|
||||
si->sin6_port = tcphdr ? tcphdr->th_dport : 0;
|
||||
si->sin6_addr = ip6hdr->ip6_dst;
|
||||
si->sin6_flowinfo = 0;
|
||||
si->sin6_scope_id = 0;
|
||||
}
|
||||
|
||||
if (src)
|
||||
{
|
||||
si = (struct sockaddr_in6*)src;
|
||||
si->sin6_family = AF_INET6;
|
||||
si->sin6_port = tcphdr ? tcphdr->th_sport : 0;
|
||||
si->sin6_addr = ip6hdr->ip6_src;
|
||||
si->sin6_flowinfo = 0;
|
||||
si->sin6_scope_id = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static const char *proto_name(uint8_t proto)
|
||||
{
|
||||
switch(proto)
|
||||
{
|
||||
case IPPROTO_TCP:
|
||||
return "tcp";
|
||||
case IPPROTO_UDP:
|
||||
return "udp";
|
||||
case IPPROTO_ICMP:
|
||||
return "icmp";
|
||||
case IPPROTO_IGMP:
|
||||
return "igmp";
|
||||
case IPPROTO_ESP:
|
||||
return "esp";
|
||||
case IPPROTO_AH:
|
||||
return "ah";
|
||||
case IPPROTO_IPV6:
|
||||
return "6in4";
|
||||
#ifdef IPPROTO_SCTP
|
||||
case IPPROTO_SCTP:
|
||||
return "sctp";
|
||||
#endif
|
||||
default:
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
static void str_proto_name(char *s, size_t s_len, uint8_t proto)
|
||||
{
|
||||
const char *name = proto_name(proto);
|
||||
if (name)
|
||||
snprintf(s,s_len,"%s",name);
|
||||
else
|
||||
snprintf(s,s_len,"%u",proto);
|
||||
}
|
||||
|
||||
static void str_srcdst_ip(char *s, size_t s_len, const void *saddr,const void *daddr)
|
||||
{
|
||||
char s_ip[16],d_ip[16];
|
||||
*s_ip=*d_ip=0;
|
||||
inet_ntop(AF_INET, saddr, s_ip, sizeof(s_ip));
|
||||
inet_ntop(AF_INET, daddr, d_ip, sizeof(d_ip));
|
||||
snprintf(s,s_len,"%s => %s",s_ip,d_ip);
|
||||
}
|
||||
static void str_ip(char *s, size_t s_len, const struct ip *ip)
|
||||
{
|
||||
char ss[35],s_proto[16];
|
||||
str_srcdst_ip(ss,sizeof(ss),&ip->ip_src,&ip->ip_dst);
|
||||
str_proto_name(s_proto,sizeof(s_proto),ip->ip_p);
|
||||
snprintf(s,s_len,"%s proto=%s",ss,s_proto);
|
||||
}
|
||||
void print_ip(const struct ip *ip)
|
||||
{
|
||||
char s[64];
|
||||
str_ip(s,sizeof(s),ip);
|
||||
printf("%s",s);
|
||||
}
|
||||
static void str_srcdst_ip6(char *s, size_t s_len, const void *saddr,const void *daddr)
|
||||
{
|
||||
char s_ip[40],d_ip[40];
|
||||
*s_ip=*d_ip=0;
|
||||
inet_ntop(AF_INET6, saddr, s_ip, sizeof(s_ip));
|
||||
inet_ntop(AF_INET6, daddr, d_ip, sizeof(d_ip));
|
||||
snprintf(s,s_len,"%s => %s",s_ip,d_ip);
|
||||
}
|
||||
static void str_ip6hdr(char *s, size_t s_len, const struct ip6_hdr *ip6hdr, uint8_t proto)
|
||||
{
|
||||
char ss[83],s_proto[16];
|
||||
str_srcdst_ip6(ss,sizeof(ss),&ip6hdr->ip6_src,&ip6hdr->ip6_dst);
|
||||
str_proto_name(s_proto,sizeof(s_proto),proto);
|
||||
snprintf(s,s_len,"%s proto=%s",ss,s_proto);
|
||||
}
|
||||
void print_ip6hdr(const struct ip6_hdr *ip6hdr, uint8_t proto)
|
||||
{
|
||||
char s[128];
|
||||
str_ip6hdr(s,sizeof(s),ip6hdr,proto);
|
||||
printf("%s",s);
|
||||
}
|
||||
|
||||
static void str_tcphdr(char *s, size_t s_len, const struct tcphdr *tcphdr)
|
||||
{
|
||||
char flags[7],*f=flags;
|
||||
if (tcphdr->th_flags & TH_SYN) *f++='S';
|
||||
if (tcphdr->th_flags & TH_ACK) *f++='A';
|
||||
if (tcphdr->th_flags & TH_RST) *f++='R';
|
||||
if (tcphdr->th_flags & TH_FIN) *f++='F';
|
||||
if (tcphdr->th_flags & TH_PUSH) *f++='P';
|
||||
if (tcphdr->th_flags & TH_URG) *f++='U';
|
||||
*f=0;
|
||||
snprintf(s,s_len,"sport=%u dport=%u flags=%s seq=%u ack_seq=%u",htons(tcphdr->th_sport),htons(tcphdr->th_dport),flags,htonl(tcphdr->th_seq),htonl(tcphdr->th_ack));
|
||||
}
|
||||
void print_tcphdr(const struct tcphdr *tcphdr)
|
||||
{
|
||||
char s[80];
|
||||
str_tcphdr(s,sizeof(s),tcphdr);
|
||||
printf("%s",s);
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
bool proto_check_ipv4(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 20 && (data[0] & 0xF0) == 0x40 &&
|
||||
len >= ((data[0] & 0x0F) << 2);
|
||||
}
|
||||
// move to transport protocol
|
||||
void proto_skip_ipv4(uint8_t **data, size_t *len)
|
||||
{
|
||||
size_t l;
|
||||
|
||||
l = (**data & 0x0F) << 2;
|
||||
*data += l;
|
||||
*len -= l;
|
||||
}
|
||||
bool proto_check_tcp(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 20 && len >= ((data[12] & 0xF0) >> 2);
|
||||
}
|
||||
void proto_skip_tcp(uint8_t **data, size_t *len)
|
||||
{
|
||||
size_t l;
|
||||
l = ((*data)[12] & 0xF0) >> 2;
|
||||
*data += l;
|
||||
*len -= l;
|
||||
}
|
||||
|
||||
bool proto_check_ipv6(const uint8_t *data, size_t len)
|
||||
{
|
||||
return len >= 40 && (data[0] & 0xF0) == 0x60 &&
|
||||
(len - 40) >= htons(*(uint16_t*)(data + 4)); // payload length
|
||||
}
|
||||
// move to transport protocol
|
||||
// proto_type = 0 => error
|
||||
void proto_skip_ipv6(uint8_t **data, size_t *len, uint8_t *proto_type)
|
||||
{
|
||||
size_t hdrlen;
|
||||
uint8_t HeaderType;
|
||||
|
||||
if (proto_type) *proto_type = 0; // put error in advance
|
||||
|
||||
HeaderType = (*data)[6]; // NextHeader field
|
||||
*data += 40; *len -= 40; // skip ipv6 base header
|
||||
while (*len > 0) // need at least one byte for NextHeader field
|
||||
{
|
||||
switch (HeaderType)
|
||||
{
|
||||
case 0: // Hop-by-Hop Options
|
||||
case 43: // routing
|
||||
case 51: // authentication
|
||||
case 60: // Destination Options
|
||||
case 135: // mobility
|
||||
case 139: // Host Identity Protocol Version v2
|
||||
case 140: // Shim6
|
||||
if (*len < 2) return; // error
|
||||
hdrlen = 8 + ((*data)[1] << 3);
|
||||
break;
|
||||
case 44: // fragment. length fixed to 8, hdrlen field defined as reserved
|
||||
hdrlen = 8;
|
||||
break;
|
||||
case 59: // no next header
|
||||
return; // error
|
||||
default:
|
||||
// we found some meaningful payload. it can be tcp, udp, icmp or some another exotic shit
|
||||
if (proto_type) *proto_type = HeaderType;
|
||||
return;
|
||||
}
|
||||
if (*len < hdrlen) return; // error
|
||||
HeaderType = **data;
|
||||
// advance to the next header location
|
||||
*len -= hdrlen;
|
||||
*data += hdrlen;
|
||||
}
|
||||
// we have garbage
|
||||
}
|
||||
|
||||
bool tcp_synack_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == (TH_ACK|TH_SYN));
|
||||
}
|
||||
bool tcp_syn_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == TH_SYN);
|
||||
}
|
||||
bool tcp_ack_segment(const struct tcphdr *tcphdr)
|
||||
{
|
||||
/* check for set bits in TCP hdr */
|
||||
return ((tcphdr->th_flags & (TH_URG|TH_ACK|TH_PUSH|TH_RST|TH_SYN|TH_FIN)) == TH_ACK);
|
||||
}
|
||||
|
||||
void tcp_rewrite_wscale(struct tcphdr *tcp, uint8_t scale_factor)
|
||||
{
|
||||
uint8_t *scale,scale_factor_old;
|
||||
|
||||
if (scale_factor!=SCALE_NONE)
|
||||
{
|
||||
scale = tcp_find_option(tcp,3); // tcp option 3 - scale factor
|
||||
if (scale && scale[1]==3) // length should be 3
|
||||
{
|
||||
scale_factor_old=scale[2];
|
||||
// do not allow increasing scale factor
|
||||
if (scale_factor>=scale_factor_old)
|
||||
DLOG("Scale factor %u unchanged\n", scale_factor_old)
|
||||
else
|
||||
{
|
||||
scale[2]=scale_factor;
|
||||
DLOG("Scale factor change %u => %u\n", scale_factor_old, scale_factor)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
// scale_factor=SCALE_NONE - do not change
|
||||
void tcp_rewrite_winsize(struct tcphdr *tcp, uint16_t winsize, uint8_t scale_factor)
|
||||
{
|
||||
uint16_t winsize_old;
|
||||
|
||||
winsize_old = htons(tcp->th_win); // << scale_factor;
|
||||
tcp->th_win = htons(winsize);
|
||||
DLOG("Window size change %u => %u\n", winsize_old, winsize)
|
||||
|
||||
tcp_rewrite_wscale(tcp, scale_factor);
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user