mirror of
https://github.com/Waujito/youtubeUnblock.git
synced 2024-12-22 06:15:31 +00:00
Carry split and detection functions to separate file
This needed to escape code duplication in further development of kernel module. Also this cleanups the code.
This commit is contained in:
Vadim Vetrov
parent
460c727dea
commit
7490658708
2
Makefile
2
Makefile
@ -17,7 +17,7 @@ export CC LD CFLAGS LDFLAGS
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APP:=$(BUILD_DIR)/youtubeUnblock
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SRCS := youtubeUnblock.c
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SRCS := youtubeUnblock.c mangle.c
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OBJS := $(SRCS:%.c=$(BUILD_DIR)/%.o)
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LIBNFNETLINK := $(DEPSDIR)/lib/libnfnetlink.a
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430
mangle.c
Normal file
430
mangle.c
Normal file
@ -0,0 +1,430 @@
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#include "mangle.h"
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#include <endian.h>
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#ifdef KERNEL_SPACE
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static __u16 nfq_checksum(__u32 sum, __u16 *buf, int size)
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{
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while (size > 1) {
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sum += *buf++;
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size -= sizeof(__u16);
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}
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if (size) {
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#if __BYTE_ORDER == __BIG_ENDIAN
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sum += (uint16_t)*(uint8_t *)buf << 8;
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#else
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sum += (__u16)*(__u8 *)buf;
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#endif
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}
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sum = (sum >> 16) + (sum & 0xffff);
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sum += (sum >> 16);
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return (__u16)(~sum);
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}
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static __u16 nfq_checksum_tcpudp_ipv4(struct iphdr *iph, __u16 protonum)
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{
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__u32 sum = 0;
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__u32 iph_len = iph->ihl*4;
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__u32 len = ntohs(iph->tot_len) - iph_len;
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__u8 *payload = (__u8 *)iph + iph_len;
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sum += (iph->saddr >> 16) & 0xFFFF;
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sum += (iph->saddr) & 0xFFFF;
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sum += (iph->daddr >> 16) & 0xFFFF;
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sum += (iph->daddr) & 0xFFFF;
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sum += htons(protonum);
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sum += htons(len);
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return nfq_checksum(sum, (__u16 *)payload, len);
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}
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static void nfq_ip_set_checksum(struct iphdr *iph)
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{
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__u32 iph_len = iph->ihl * 4;
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iph->check = 0;
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iph->check = nfq_checksum(0, (__u16 *)iph, iph_len);
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}
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static void
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nfq_tcp_compute_checksum_ipv4(struct tcphdr *tcph, struct iphdr *iph)
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{
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/* checksum field in header needs to be zero for calculation. */
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tcph->check = 0;
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tcph->check = nfq_checksum_tcpudp_ipv4(iph, IPPROTO_TCP);
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}
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#else
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#include <stdio.h>
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#include <libnetfilter_queue/libnetfilter_queue_ipv4.h>
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#include <libnetfilter_queue/libnetfilter_queue_tcp.h>
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typedef uint8_t __u8;
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typedef uint32_t __u32;
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typedef uint16_t __u16;
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#endif
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int ip4_payload_split(__u8 *pkt, __u32 buflen,
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struct iphdr **iph, __u32 *iph_len,
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__u8 **payload, __u32 *plen) {
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if (pkt == NULL || buflen < sizeof(struct iphdr)) {
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return -EINVAL;
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}
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struct iphdr *hdr = (struct iphdr *)pkt;
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if (hdr->version != IPVERSION) return -EINVAL;
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__u32 hdr_len = hdr->ihl * 4;
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__u32 pktlen = ntohs(hdr->tot_len);
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if (pktlen < buflen || hdr_len > pktlen) return -EINVAL;
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if (iph)
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*iph = hdr;
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if (iph_len)
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*iph_len = hdr_len;
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if (payload)
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*payload = pkt + hdr_len;
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if (plen)
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*plen = pktlen - hdr_len;
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return 0;
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}
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int tcp4_payload_split(__u8 *pkt, __u32 buflen,
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struct iphdr **iph, __u32 *iph_len,
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struct tcphdr **tcph, __u32 *tcph_len,
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__u8 **payload, __u32 *plen) {
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struct iphdr *hdr;
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__u32 hdr_len;
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struct tcphdr *thdr;
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__u32 thdr_len;
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__u8 *tcph_pl;
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__u32 tcph_plen;
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if (ip4_payload_split(pkt, buflen, &hdr, &hdr_len,
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&tcph_pl, &tcph_plen)){
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return -EINVAL;
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}
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if (
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hdr->protocol != IPPROTO_TCP ||
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!(ntohs(hdr->frag_off) & IP_DF) ||
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tcph_plen < sizeof(struct tcphdr)) {
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return -EINVAL;
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}
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thdr = (struct tcphdr *)(tcph_pl);
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thdr_len = (*tcph)->doff * 4;
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if (thdr_len > tcph_plen) {
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return -EINVAL;
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}
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if (iph) *iph = hdr;
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if (iph_len) *iph_len = hdr_len;
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if (tcph) *tcph = thdr;
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if (tcph_len) *tcph_len = thdr_len;
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if (payload) *payload = tcph_pl + thdr_len;
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if (plen) *plen = tcph_plen - thdr_len;
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return 0;
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}
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// split packet to two ipv4 fragments.
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int ip4_frag(const __u8 *pkt, __u32 buflen, __u32 payload_offset,
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__u8 *frag1, __u32 *f1len,
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__u8 *frag2, __u32 *f2len) {
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struct iphdr *hdr;
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const __u8 *payload;
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__u32 plen;
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__u32 hdr_len;
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if (ip4_payload_split(
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(__u8 *)pkt, buflen,
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&hdr, &hdr_len, (__u8 **)&payload, &plen)) {
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return -EINVAL;
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}
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if (plen <= payload_offset) {
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return -EINVAL;
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}
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if (payload_offset & ((1 << 3) - 1)) {
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#ifdef KERNEL_SPACE
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#else
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errno = EINVAL;
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perror("Payload offset MUST be a multiply of 8!");
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#endif
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return -EINVAL;
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}
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__u32 f1_plen = payload_offset;
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__u32 f1_dlen = f1_plen + hdr_len;
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__u32 f2_plen = plen - payload_offset;
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__u32 f2_dlen = f2_plen + hdr_len;
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if (*f1len < f1_dlen || *f2len < f2_dlen) {
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return -ENOMEM;
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}
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*f1len = f1_dlen;
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*f2len = f2_dlen;
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memcpy(frag1, hdr, hdr_len);
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memcpy(frag2, hdr, hdr_len);
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memcpy(frag1 + hdr_len, payload, f1_plen);
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memcpy(frag2 + hdr_len, payload + payload_offset, f2_plen);
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struct iphdr *f1_hdr = (void *)frag1;
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struct iphdr *f2_hdr = (void *)frag2;
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__u16 f1_frag_off = ntohs(f1_hdr->frag_off);
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__u16 f2_frag_off = ntohs(f2_hdr->frag_off);
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f1_frag_off &= IP_OFFMASK;
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f1_frag_off |= IP_MF;
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if ((f2_frag_off & ~IP_OFFMASK) == IP_MF) {
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f2_frag_off &= IP_OFFMASK;
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f2_frag_off |= IP_MF;
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} else {
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f2_frag_off &= IP_OFFMASK;
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}
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f2_frag_off += (__u16)payload_offset / 8;
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f1_hdr->frag_off = htons(f1_frag_off);
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f1_hdr->tot_len = htons(f1_dlen);
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f2_hdr->frag_off = htons(f2_frag_off);
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f2_hdr->tot_len = htons(f2_dlen);
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#if defined(DEBUG) && !defined(KERNEL_SPACE)
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printf("Packet split in portion %u %u\n", f1_plen, f2_plen);
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#endif
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nfq_ip_set_checksum(f1_hdr);
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nfq_ip_set_checksum(f2_hdr);
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return 0;
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}
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// split packet to two tcp-on-ipv4 segments.
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int tcp4_frag(const __u8 *pkt, __u32 buflen, __u32 payload_offset,
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__u8 *seg1, __u32 *s1len,
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__u8 *seg2, __u32 *s2len) {
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struct iphdr *hdr;
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__u32 hdr_len;
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struct tcphdr *tcph;
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__u32 tcph_len;
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__u32 plen;
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const __u8 *payload;
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if (tcp4_payload_split((__u8 *)pkt, buflen,
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&hdr, &hdr_len,
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&tcph, &tcph_len,
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(__u8 **)&payload, &plen)) {
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return -EINVAL;
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}
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if (plen <= payload_offset) {
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return -EINVAL;
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}
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__u32 s1_plen = payload_offset;
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__u32 s1_dlen = s1_plen + hdr_len + tcph_len;
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__u32 s2_plen = plen - payload_offset;
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__u32 s2_dlen = s2_plen + hdr_len + tcph_len;
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if (*s1len < s1_dlen || *s2len < s2_dlen) return -ENOMEM;
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*s1len = s1_dlen;
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*s2len = s2_dlen;
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memcpy(seg1, hdr, hdr_len);
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memcpy(seg2, hdr, hdr_len);
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memcpy(seg1 + hdr_len, tcph, tcph_len);
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memcpy(seg2 + hdr_len, tcph, tcph_len);
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memcpy(seg1 + hdr_len + tcph_len, payload, s1_plen);
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memcpy(seg2 + hdr_len + tcph_len, payload + payload_offset, s2_plen);
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struct iphdr *s1_hdr = (void *)seg1;
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struct iphdr *s2_hdr = (void *)seg2;
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struct tcphdr *s1_tcph = (void *)(seg1 + hdr_len);
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struct tcphdr *s2_tcph = (void *)(seg2 + hdr_len);
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s1_hdr->tot_len = htons(s1_dlen);
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s2_hdr->tot_len = htons(s2_dlen);
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s2_tcph->seq = htonl(ntohl(s2_tcph->seq) + payload_offset);
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#if defined(DEBUG) && !defined(KERNEL_SPACE)
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printf("Packet split in portion %u %u\n", s1_plen, s2_plen);
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#endif
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nfq_tcp_compute_checksum_ipv4(s1_tcph, s1_hdr);
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nfq_tcp_compute_checksum_ipv4(s2_tcph, s2_hdr);
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return 0;
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}
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#define TLS_CONTENT_TYPE_HANDSHAKE 0x16
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#define TLS_HANDSHAKE_TYPE_CLIENT_HELLO 0x01
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#define TLS_EXTENSION_SNI 0x0000
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#define TLS_EXTENSION_CLIENT_HELLO_ENCRYPTED 0xfe0d
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const char googlevideo_ending[] = "googlevideo.com";
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const int googlevideo_len = 15;
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#define GOOGLEVIDEO_MARK 0xfc74
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typedef __u8 uint8_t;
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typedef __u32 uint32_t;
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typedef __u16 uint16_t;
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/**
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* Processes tls payload of the tcp request.
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*
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* data Payload data of TCP.
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* dlen Length of `data`.
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*/
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struct verdict analyze_tls_data(
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const uint8_t *data,
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uint32_t dlen)
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{
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struct verdict vrd = {0};
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size_t i = 0;
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const uint8_t *data_end = data + dlen;
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while (i + 4 < dlen) {
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const uint8_t *msgData = data + i;
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uint8_t tls_content_type = *msgData;
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uint8_t tls_vmajor = *(msgData + 1);
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uint8_t tls_vminor = *(msgData + 2);
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uint16_t message_length = ntohs(*(uint16_t *)(msgData + 3));
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const uint8_t *message_length_ptr = msgData + 3;
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if (i + 5 + message_length > dlen) break;
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if (tls_content_type != TLS_CONTENT_TYPE_HANDSHAKE)
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goto nextMessage;
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const uint8_t *handshakeProto = msgData + 5;
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if (handshakeProto + 1 >= data_end) break;
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uint8_t handshakeType = *handshakeProto;
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if (handshakeType != TLS_HANDSHAKE_TYPE_CLIENT_HELLO)
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goto nextMessage;
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const uint8_t *msgPtr = handshakeProto;
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msgPtr += 1;
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const uint8_t *handshakeProto_length_ptr = msgPtr + 1;
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msgPtr += 3 + 2 + 32;
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if (msgPtr + 1 >= data_end) break;
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uint8_t sessionIdLength = *msgPtr;
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msgPtr++;
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msgPtr += sessionIdLength;
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if (msgPtr + 2 >= data_end) break;
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uint16_t ciphersLength = ntohs(*(uint16_t *)msgPtr);
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msgPtr += 2;
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msgPtr += ciphersLength;
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if (msgPtr + 1 >= data_end) break;
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uint8_t compMethodsLen = *msgPtr;
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msgPtr++;
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msgPtr += compMethodsLen;
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if (msgPtr + 2 >= data_end) break;
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uint16_t extensionsLen = ntohs(*(uint16_t *)msgPtr);
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const uint8_t *extensionsLen_ptr = msgPtr;
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msgPtr += 2;
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const uint8_t *extensionsPtr = msgPtr;
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const uint8_t *extensions_end = extensionsPtr + extensionsLen;
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if (extensions_end > data_end) break;
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while (extensionsPtr < extensions_end) {
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const uint8_t *extensionPtr = extensionsPtr;
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if (extensionPtr + 4 >= extensions_end) break;
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uint16_t extensionType =
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ntohs(*(uint16_t *)extensionPtr);
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extensionPtr += 2;
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uint16_t extensionLen =
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ntohs(*(uint16_t *)extensionPtr);
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const uint8_t *extensionLen_ptr = extensionPtr;
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extensionPtr += 2;
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if (extensionPtr + extensionLen > extensions_end)
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break;
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if (extensionType != TLS_EXTENSION_SNI)
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goto nextExtension;
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const uint8_t *sni_ext_ptr = extensionPtr;
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if (sni_ext_ptr + 2 >= extensions_end) break;
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uint16_t sni_ext_dlen = ntohs(*(uint16_t *)sni_ext_ptr);
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const uint8_t *sni_ext_dlen_ptr = sni_ext_ptr;
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sni_ext_ptr += 2;
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const uint8_t *sni_ext_end = sni_ext_ptr + sni_ext_dlen;
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if (sni_ext_end >= extensions_end) break;
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|
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if (sni_ext_ptr + 3 >= sni_ext_end) break;
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uint8_t sni_type = *sni_ext_ptr++;
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uint16_t sni_len = ntohs(*(uint16_t *)sni_ext_ptr);
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sni_ext_ptr += 2;
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if (sni_ext_ptr + sni_len > sni_ext_end) break;
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char *sni_name = (char *)sni_ext_ptr;
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// sni_len
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vrd.sni_offset = (uint8_t *)sni_name - data;
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vrd.sni_len = sni_len;
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char *gv_startp = sni_name + sni_len - googlevideo_len;
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if (sni_len >= googlevideo_len &&
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sni_len < 128 &&
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!strncmp(gv_startp,
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googlevideo_ending,
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googlevideo_len)) {
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|
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vrd.gvideo_hello = 1;
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}
|
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|
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nextExtension:
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extensionsPtr += 2 + 2 + extensionLen;
|
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}
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nextMessage:
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i += 5 + message_length;
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}
|
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|
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return vrd;
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}
|
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|
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63
mangle.h
Normal file
63
mangle.h
Normal file
@ -0,0 +1,63 @@
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#ifndef YU_MANGLE_H
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#define YU_MANGLE_H
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#define RAWSOCKET_MARK 0xfc70
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|
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#ifdef KERNEL_SPACE
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#include <linux/types.h>
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typedef __u8 uint8_t;
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typedef __u32 uint32_t;
|
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|
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/stddef.h>
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#include <linux/net.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/tcp.h>
|
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|
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#include <asm/byteorder.h>
|
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#define ntohs(x) __constant_ntohs(x)
|
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#define ntohl(x) __constant_ntohl(x)
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#define htons(x) __constant_htons(x)
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#define htonl(x) __constant_htonl(x)
|
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|
||||
#define IP_RF 0x8000 /* reserved fragment flag */
|
||||
#define IP_DF 0x4000 /* dont fragment flag */
|
||||
#define IP_MF 0x2000 /* more fragments flag */
|
||||
#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
|
||||
#else
|
||||
#include <stdint.h>
|
||||
#include <string.h>
|
||||
#include <errno.h>
|
||||
#include <arpa/inet.h>
|
||||
#include <netinet/ip.h>
|
||||
#include <netinet/tcp.h>
|
||||
#endif
|
||||
|
||||
struct verdict {
|
||||
int gvideo_hello; /* google video hello packet */
|
||||
int sni_offset; /* offset from start of tcp _payload_ */
|
||||
int sni_len;
|
||||
};
|
||||
|
||||
struct verdict analyze_tls_data(const uint8_t *data, uint32_t dlen);
|
||||
|
||||
int ip4_frag(const uint8_t *pkt, uint32_t pktlen,
|
||||
uint32_t payload_offset,
|
||||
uint8_t *frag1, uint32_t *f1len,
|
||||
uint8_t *frag2, uint32_t *f2len);
|
||||
|
||||
int tcp4_frag(const uint8_t *pkt, uint32_t pktlen,
|
||||
uint32_t payload_offset,
|
||||
uint8_t *seg1, uint32_t *s1len,
|
||||
uint8_t *seg2, uint32_t *s2len);
|
||||
|
||||
int ip4_payload_split(uint8_t *pkt, uint32_t buflen,
|
||||
struct iphdr **iph, uint32_t *iph_len,
|
||||
uint8_t **payload, uint32_t *plen);
|
||||
|
||||
int tcp4_payload_split(uint8_t *pkt, uint32_t buflen,
|
||||
struct iphdr **iph, uint32_t *iph_len,
|
||||
struct tcphdr **tcph, uint32_t *tcph_len,
|
||||
uint8_t **payload, uint32_t *plen);
|
||||
#endif /* YU_MANGLE_H */
|
||||
428
youtubeUnblock.c
428
youtubeUnblock.c
@ -1,10 +1,15 @@
|
||||
#define _GNU_SOURCE
|
||||
#ifndef __linux__
|
||||
#error "The package is linux only!"
|
||||
#endif
|
||||
|
||||
#ifdef KERNEL_SPACE
|
||||
#error "The build aims to the kernel, not userspace"
|
||||
#endif
|
||||
|
||||
#include <libnetfilter_queue/linux_nfnetlink_queue.h>
|
||||
#include <stdio.h>
|
||||
#include <errno.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <arpa/inet.h>
|
||||
|
||||
#include <libmnl/libmnl.h>
|
||||
#include <libnetfilter_queue/libnetfilter_queue.h>
|
||||
@ -21,6 +26,7 @@
|
||||
#include <sys/socket.h>
|
||||
|
||||
#include <pthread.h>
|
||||
#include "mangle.h"
|
||||
|
||||
#ifndef NOUSE_GSO
|
||||
#define USE_GSO
|
||||
@ -41,9 +47,6 @@
|
||||
#error "Too much threads"
|
||||
#endif
|
||||
|
||||
#ifndef __linux__
|
||||
#error "The package is linux only!"
|
||||
#endif
|
||||
|
||||
static struct {
|
||||
uint32_t queue_start_num;
|
||||
@ -173,229 +176,63 @@ static int close_raw_socket(void) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
// split packet to two ipv4 fragments.
|
||||
static int ipv4_frag(struct pkt_buff *pktb, size_t payload_offset,
|
||||
struct pkt_buff **frag1, struct pkt_buff **frag2) {
|
||||
uint8_t buff1[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint8_t buff2[MNL_SOCKET_BUFFER_SIZE];
|
||||
|
||||
struct iphdr *hdr = nfq_ip_get_hdr(pktb);
|
||||
size_t hdr_len = hdr->ihl * 4;
|
||||
|
||||
uint8_t *payload = pktb_data(pktb) + hdr_len;
|
||||
size_t plen = pktb_len(pktb) - hdr_len;
|
||||
|
||||
if (hdr == NULL || payload == NULL || plen <= payload_offset) {
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (payload_offset & ((1 << 3) - 1)) {
|
||||
fprintf(stderr, "Payload offset MUST be a multiply of 8!\n");
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
size_t f1_plen = payload_offset;
|
||||
size_t f1_dlen = f1_plen + hdr_len;
|
||||
|
||||
size_t f2_plen = plen - payload_offset;
|
||||
size_t f2_dlen = f2_plen + hdr_len;
|
||||
|
||||
memcpy(buff1, hdr, hdr_len);
|
||||
memcpy(buff2, hdr, hdr_len);
|
||||
|
||||
memcpy(buff1 + hdr_len, payload, f1_plen);
|
||||
memcpy(buff2 + hdr_len, payload + payload_offset, f2_plen);
|
||||
|
||||
struct iphdr *f1_hdr = (void *)buff1;
|
||||
struct iphdr *f2_hdr = (void *)buff2;
|
||||
|
||||
uint16_t f1_frag_off = ntohs(f1_hdr->frag_off);
|
||||
uint16_t f2_frag_off = ntohs(f2_hdr->frag_off);
|
||||
|
||||
f1_frag_off &= IP_OFFMASK;
|
||||
f1_frag_off |= IP_MF;
|
||||
|
||||
if ((f2_frag_off & ~IP_OFFMASK) == IP_MF) {
|
||||
f2_frag_off &= IP_OFFMASK;
|
||||
f2_frag_off |= IP_MF;
|
||||
} else {
|
||||
f2_frag_off &= IP_OFFMASK;
|
||||
}
|
||||
|
||||
f2_frag_off += (uint16_t)payload_offset / 8;
|
||||
|
||||
f1_hdr->frag_off = htons(f1_frag_off);
|
||||
f1_hdr->tot_len = htons(f1_dlen);
|
||||
|
||||
f2_hdr->frag_off = htons(f2_frag_off);
|
||||
f2_hdr->tot_len = htons(f2_dlen);
|
||||
|
||||
|
||||
#ifdef DEBUG
|
||||
printf("Packet split in portion %zu %zu\n", f1_dlen, f2_dlen);
|
||||
#endif
|
||||
|
||||
nfq_ip_set_checksum(f1_hdr);
|
||||
nfq_ip_set_checksum(f2_hdr);
|
||||
|
||||
*frag1 = pktb_alloc(AF_INET, buff1, f1_dlen, 0);
|
||||
if (*frag1 == NULL)
|
||||
return -1;
|
||||
|
||||
*frag2 = pktb_alloc(AF_INET, buff2, f2_dlen, 0);
|
||||
if (*frag2 == NULL) {
|
||||
pktb_free(*frag1);
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
// split packet to two tcp-on-ipv4 segments.
|
||||
static int tcp4_frag(struct pkt_buff *pktb, size_t payload_offset,
|
||||
struct pkt_buff **seg1, struct pkt_buff **seg2) {
|
||||
uint8_t buff1[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint8_t buff2[MNL_SOCKET_BUFFER_SIZE];
|
||||
|
||||
struct iphdr *hdr = nfq_ip_get_hdr(pktb);
|
||||
size_t hdr_len = hdr->ihl * 4;
|
||||
if (hdr == NULL) {errno = EINVAL; return -1;}
|
||||
if (hdr->protocol != IPPROTO_TCP || !(ntohs(hdr->frag_off) & IP_DF)) {
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (nfq_ip_set_transport_header(pktb, hdr))
|
||||
return -1;
|
||||
|
||||
struct tcphdr *tcph = nfq_tcp_get_hdr(pktb);
|
||||
size_t tcph_len = tcph->doff * 4;
|
||||
if (tcph == NULL) {
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
uint8_t *payload = nfq_tcp_get_payload(tcph, pktb);
|
||||
size_t plen = nfq_tcp_get_payload_len(tcph, pktb);
|
||||
|
||||
if (hdr == NULL || payload == NULL || plen <= payload_offset) {
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
size_t s1_plen = payload_offset;
|
||||
size_t s1_dlen = s1_plen + hdr_len + tcph_len;
|
||||
|
||||
size_t s2_plen = plen - payload_offset;
|
||||
size_t s2_dlen = s2_plen + hdr_len + tcph_len;
|
||||
|
||||
memcpy(buff1, hdr, hdr_len);
|
||||
memcpy(buff2, hdr, hdr_len);
|
||||
|
||||
memcpy(buff1 + hdr_len, tcph, tcph_len);
|
||||
memcpy(buff2 + hdr_len, tcph, tcph_len);
|
||||
|
||||
memcpy(buff1 + hdr_len + tcph_len, payload, s1_plen);
|
||||
memcpy(buff2 + hdr_len + tcph_len, payload + payload_offset, s2_plen);
|
||||
|
||||
struct iphdr *s1_hdr = (void *)buff1;
|
||||
struct iphdr *s2_hdr = (void *)buff2;
|
||||
|
||||
struct tcphdr *s1_tcph = (void *)(buff1 + hdr_len);
|
||||
struct tcphdr *s2_tcph = (void *)(buff2 + hdr_len);
|
||||
|
||||
s1_hdr->tot_len = htons(s1_dlen);
|
||||
s2_hdr->tot_len = htons(s2_dlen);
|
||||
|
||||
// s2_hdr->id = htons(ntohs(s1_hdr->id) + 1);
|
||||
s2_tcph->seq = htonl(ntohl(s2_tcph->seq) + payload_offset);
|
||||
// printf("%zu %du %du\n", payload_offset, ntohs(s1_tcph->seq), ntohs(s2_tcph->seq));
|
||||
|
||||
#ifdef DEBUG
|
||||
printf("Packet split in portion %zu %zu\n", s1_dlen, s2_dlen);
|
||||
#endif
|
||||
|
||||
nfq_tcp_compute_checksum_ipv4(s1_tcph, s1_hdr);
|
||||
nfq_tcp_compute_checksum_ipv4(s2_tcph, s2_hdr);
|
||||
|
||||
*seg1 = pktb_alloc(AF_INET, buff1, s1_dlen, 0);
|
||||
if (*seg1 == NULL)
|
||||
return -1;
|
||||
|
||||
*seg2 = pktb_alloc(AF_INET, buff2, s2_dlen, 0);
|
||||
if (*seg2 == NULL) {
|
||||
pktb_free(*seg1);
|
||||
return -1;
|
||||
}
|
||||
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#define AVAILABLE_MTU 1384
|
||||
|
||||
static int send_raw_socket(struct pkt_buff *pktb) {
|
||||
if (pktb_len(pktb) > AVAILABLE_MTU) {
|
||||
static int send_raw_socket(const uint8_t *pkt, uint32_t pktlen) {
|
||||
if (pktlen > AVAILABLE_MTU) {
|
||||
#ifdef DEBUG
|
||||
printf("Split packet!\n");
|
||||
#endif
|
||||
|
||||
struct pkt_buff *buff1;
|
||||
struct pkt_buff *buff2;
|
||||
uint8_t buff1[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint32_t buff1_size = MNL_SOCKET_BUFFER_SIZE;
|
||||
uint8_t buff2[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint32_t buff2_size = MNL_SOCKET_BUFFER_SIZE;
|
||||
|
||||
#ifdef USE_TCP_SEGMENTATION
|
||||
if (tcp4_frag(pktb, AVAILABLE_MTU-128, &buff1, &buff2) < 0)
|
||||
if ((errno = tcp4_frag(pkt, pktlen, AVAILABLE_MTU-128,
|
||||
buff1, &buff1_size, buff2, &buff2_size)) < 0)
|
||||
return -1;
|
||||
#else
|
||||
if (ipv4_frag(pktb, AVAILABLE_MTU-128, &buff1, &buff2) < 0)
|
||||
if ((errno = ip4_frag(pkt, pktlen, AVAILABLE_MTU-128,
|
||||
buff1, &buff1_size, buff2, &buff2_size)) < 0)
|
||||
return -1;
|
||||
|
||||
#endif
|
||||
|
||||
int sent = 0;
|
||||
int status = send_raw_socket(buff1);
|
||||
int status = send_raw_socket(buff1, buff1_size);
|
||||
|
||||
if (status >= 0) sent += status;
|
||||
else {
|
||||
pktb_free(buff1);
|
||||
pktb_free(buff2);
|
||||
return status;
|
||||
}
|
||||
pktb_free(buff1);
|
||||
|
||||
status = send_raw_socket(buff2);
|
||||
status = send_raw_socket(buff2, buff2_size);
|
||||
if (status >= 0) sent += status;
|
||||
else {
|
||||
pktb_free(buff2);
|
||||
return status;
|
||||
}
|
||||
pktb_free(buff2);
|
||||
|
||||
return sent;
|
||||
}
|
||||
|
||||
struct iphdr *iph = nfq_ip_get_hdr(pktb);
|
||||
if (iph == NULL)
|
||||
return -1;
|
||||
|
||||
if(nfq_ip_set_transport_header(pktb, iph))
|
||||
struct iphdr *iph;
|
||||
|
||||
if ((errno = ip4_payload_split(
|
||||
(uint8_t *)pkt, pktlen, &iph, NULL, NULL, NULL)) < 0) {
|
||||
errno *= -1;
|
||||
return -1;
|
||||
}
|
||||
|
||||
|
||||
int sin_port = 0;
|
||||
|
||||
struct tcphdr *tcph = nfq_tcp_get_hdr(pktb);
|
||||
struct udphdr *udph = nfq_udp_get_hdr(pktb);
|
||||
|
||||
if (tcph != NULL) {
|
||||
struct tcphdr *tcph;
|
||||
if (tcp4_payload_split((uint8_t *)pkt, pktlen, NULL, NULL, &tcph, NULL, NULL, NULL) == 0)
|
||||
sin_port = tcph->dest;
|
||||
errno = 0;
|
||||
} else if (udph != NULL) {
|
||||
sin_port = udph->dest;
|
||||
} else {
|
||||
return -1;
|
||||
}
|
||||
|
||||
struct sockaddr_in daddr = {
|
||||
.sin_family = AF_INET,
|
||||
@ -408,7 +245,7 @@ static int send_raw_socket(struct pkt_buff *pktb) {
|
||||
pthread_mutex_lock(&config.rawsocket_lock);
|
||||
|
||||
int sent = sendto(config.rawsocket,
|
||||
pktb_data(pktb), pktb_len(pktb), 0,
|
||||
pkt, pktlen, 0,
|
||||
(struct sockaddr *)&daddr, sizeof(daddr));
|
||||
|
||||
pthread_mutex_unlock(&config.rawsocket_lock);
|
||||
@ -426,160 +263,13 @@ struct packet_data {
|
||||
};
|
||||
|
||||
|
||||
#define TLS_CONTENT_TYPE_HANDSHAKE 0x16
|
||||
#define TLS_HANDSHAKE_TYPE_CLIENT_HELLO 0x01
|
||||
#define TLS_EXTENSION_SNI 0x0000
|
||||
#define TLS_EXTENSION_CLIENT_HELLO_ENCRYPTED 0xfe0d
|
||||
|
||||
const char googlevideo_ending[] = "googlevideo.com";
|
||||
const int googlevideo_len = 15;
|
||||
|
||||
#define GOOGLEVIDEO_MARK 0xfc74
|
||||
|
||||
struct verdict {
|
||||
int gvideo_hello; /* google video hello packet */
|
||||
int sni_offset; /* offset from start of tcp _payload_ */
|
||||
int sni_len;
|
||||
};
|
||||
|
||||
/**
|
||||
* Processes tls payload of the tcp request.
|
||||
*
|
||||
* data Payload data of TCP.
|
||||
* dlen Length of `data`.
|
||||
*/
|
||||
static struct verdict analyze_tls_data(
|
||||
const uint8_t *data,
|
||||
uint32_t dlen)
|
||||
{
|
||||
struct verdict vrd = {0};
|
||||
|
||||
size_t i = 0;
|
||||
const uint8_t *data_end = data + dlen;
|
||||
|
||||
while (i + 4 < dlen) {
|
||||
const uint8_t *msgData = data + i;
|
||||
|
||||
uint8_t tls_content_type = *msgData;
|
||||
uint8_t tls_vmajor = *(msgData + 1);
|
||||
uint8_t tls_vminor = *(msgData + 2);
|
||||
uint16_t message_length = ntohs(*(uint16_t *)(msgData + 3));
|
||||
const uint8_t *message_length_ptr = msgData + 3;
|
||||
|
||||
|
||||
if (i + 5 + message_length > dlen) break;
|
||||
|
||||
if (tls_content_type != TLS_CONTENT_TYPE_HANDSHAKE)
|
||||
goto nextMessage;
|
||||
|
||||
|
||||
const uint8_t *handshakeProto = msgData + 5;
|
||||
|
||||
if (handshakeProto + 1 >= data_end) break;
|
||||
|
||||
uint8_t handshakeType = *handshakeProto;
|
||||
|
||||
if (handshakeType != TLS_HANDSHAKE_TYPE_CLIENT_HELLO)
|
||||
goto nextMessage;
|
||||
|
||||
const uint8_t *msgPtr = handshakeProto;
|
||||
msgPtr += 1;
|
||||
const uint8_t *handshakeProto_length_ptr = msgPtr + 1;
|
||||
msgPtr += 3 + 2 + 32;
|
||||
|
||||
if (msgPtr + 1 >= data_end) break;
|
||||
uint8_t sessionIdLength = *msgPtr;
|
||||
msgPtr++;
|
||||
msgPtr += sessionIdLength;
|
||||
|
||||
if (msgPtr + 2 >= data_end) break;
|
||||
uint16_t ciphersLength = ntohs(*(uint16_t *)msgPtr);
|
||||
msgPtr += 2;
|
||||
msgPtr += ciphersLength;
|
||||
|
||||
if (msgPtr + 1 >= data_end) break;
|
||||
uint8_t compMethodsLen = *msgPtr;
|
||||
msgPtr++;
|
||||
msgPtr += compMethodsLen;
|
||||
|
||||
if (msgPtr + 2 >= data_end) break;
|
||||
uint16_t extensionsLen = ntohs(*(uint16_t *)msgPtr);
|
||||
const uint8_t *extensionsLen_ptr = msgPtr;
|
||||
msgPtr += 2;
|
||||
|
||||
const uint8_t *extensionsPtr = msgPtr;
|
||||
const uint8_t *extensions_end = extensionsPtr + extensionsLen;
|
||||
if (extensions_end > data_end) break;
|
||||
|
||||
while (extensionsPtr < extensions_end) {
|
||||
const uint8_t *extensionPtr = extensionsPtr;
|
||||
if (extensionPtr + 4 >= extensions_end) break;
|
||||
|
||||
uint16_t extensionType =
|
||||
ntohs(*(uint16_t *)extensionPtr);
|
||||
extensionPtr += 2;
|
||||
|
||||
uint16_t extensionLen =
|
||||
ntohs(*(uint16_t *)extensionPtr);
|
||||
const uint8_t *extensionLen_ptr = extensionPtr;
|
||||
extensionPtr += 2;
|
||||
|
||||
|
||||
if (extensionPtr + extensionLen > extensions_end)
|
||||
break;
|
||||
|
||||
if (extensionType != TLS_EXTENSION_SNI)
|
||||
goto nextExtension;
|
||||
|
||||
const uint8_t *sni_ext_ptr = extensionPtr;
|
||||
|
||||
if (sni_ext_ptr + 2 >= extensions_end) break;
|
||||
uint16_t sni_ext_dlen = ntohs(*(uint16_t *)sni_ext_ptr);
|
||||
|
||||
const uint8_t *sni_ext_dlen_ptr = sni_ext_ptr;
|
||||
sni_ext_ptr += 2;
|
||||
|
||||
const uint8_t *sni_ext_end = sni_ext_ptr + sni_ext_dlen;
|
||||
if (sni_ext_end >= extensions_end) break;
|
||||
|
||||
if (sni_ext_ptr + 3 >= sni_ext_end) break;
|
||||
uint8_t sni_type = *sni_ext_ptr++;
|
||||
uint16_t sni_len = ntohs(*(uint16_t *)sni_ext_ptr);
|
||||
sni_ext_ptr += 2;
|
||||
|
||||
if (sni_ext_ptr + sni_len > sni_ext_end) break;
|
||||
|
||||
char *sni_name = (char *)sni_ext_ptr;
|
||||
// sni_len
|
||||
|
||||
vrd.sni_offset = (uint8_t *)sni_name - data;
|
||||
vrd.sni_len = sni_len;
|
||||
|
||||
char *gv_startp = sni_name + sni_len - googlevideo_len;
|
||||
if (sni_len >= googlevideo_len &&
|
||||
sni_len < 128 &&
|
||||
!strncmp(gv_startp,
|
||||
googlevideo_ending,
|
||||
googlevideo_len)) {
|
||||
|
||||
vrd.gvideo_hello = 1;
|
||||
}
|
||||
|
||||
nextExtension:
|
||||
extensionsPtr += 2 + 2 + extensionLen;
|
||||
}
|
||||
nextMessage:
|
||||
i += 5 + message_length;
|
||||
}
|
||||
|
||||
return vrd;
|
||||
}
|
||||
|
||||
// Per-queue data. Passed to queue_cb.
|
||||
struct queue_data {
|
||||
struct mnl_socket **_nl;
|
||||
int queue_num;
|
||||
};
|
||||
|
||||
|
||||
/**
|
||||
* Used to accept unsupported packets (GSOs)
|
||||
*/
|
||||
@ -655,8 +345,10 @@ static int process_packet(const struct packet_data packet, struct queue_data qda
|
||||
#endif
|
||||
}
|
||||
|
||||
struct pkt_buff *frag1;
|
||||
struct pkt_buff *frag2;
|
||||
uint8_t frag1[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint8_t frag2[MNL_SOCKET_BUFFER_SIZE];
|
||||
uint32_t f1len = MNL_SOCKET_BUFFER_SIZE;
|
||||
uint32_t f2len = MNL_SOCKET_BUFFER_SIZE;
|
||||
nfq_nlmsg_verdict_put(verdnlh, packet.id, NF_DROP);
|
||||
|
||||
|
||||
@ -664,26 +356,18 @@ static int process_packet(const struct packet_data packet, struct queue_data qda
|
||||
size_t ipd_offset = vrd.sni_offset;
|
||||
size_t mid_offset = ipd_offset + vrd.sni_len / 2;
|
||||
|
||||
struct pkt_buff *pktb = pktb_alloc(
|
||||
family,
|
||||
packet.payload,
|
||||
packet.payload_len,
|
||||
0);
|
||||
|
||||
if (tcp4_frag(pktb, mid_offset, &frag1, &frag2) < 0) {
|
||||
if ((errno = tcp4_frag(raw_payload, raw_payload_len,
|
||||
mid_offset, frag1, &f1len, frag2, &f2len)) < 0) {
|
||||
errno *= -1;
|
||||
perror("tcp4_frag");
|
||||
pktb_free(pktb);
|
||||
goto fallback;
|
||||
}
|
||||
|
||||
if ((send_raw_socket(frag2) == -1) || (send_raw_socket(frag1) == -1)) {
|
||||
if ((send_raw_socket(frag2, f2len) < 0) ||
|
||||
(send_raw_socket(frag1, f1len) < 0)) {
|
||||
perror("raw frags send");
|
||||
}
|
||||
|
||||
pktb_free(frag1);
|
||||
pktb_free(frag2);
|
||||
pktb_free(pktb);
|
||||
|
||||
#else
|
||||
// TODO: Implement compute of tcp checksum
|
||||
// GSO may turn kernel to not compute the tcp checksum.
|
||||
@ -695,18 +379,18 @@ static int process_packet(const struct packet_data packet, struct queue_data qda
|
||||
size_t mid_offset = ipd_offset + vrd.sni_len / 2;
|
||||
mid_offset += 8 - mid_offset % 8;
|
||||
|
||||
|
||||
if (ipv4_frag(pktb, mid_offset, &frag1, &frag2) < 0) {
|
||||
perror("ipv4_frag");
|
||||
if ((errno = ip4_frag(raw_payload, raw_payload_len,
|
||||
mid_offset, frag1, &f1len, frag2, &f2len)) < 0) {
|
||||
errno *= -1;
|
||||
perror("ip4_frag");
|
||||
goto fallback;
|
||||
}
|
||||
|
||||
if ((send_raw_socket(frag1) == -1) || (send_raw_socket(frag2) == -1)) {
|
||||
if ((send_raw_socket(frag2, f2len) < 0) ||
|
||||
(send_raw_socket(frag1, f1len) < 0)) {
|
||||
perror("raw frags send");
|
||||
}
|
||||
|
||||
pktb_free(frag1);
|
||||
pktb_free(frag2);
|
||||
#endif
|
||||
|
||||
}
|
||||
@ -780,6 +464,8 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data) {
|
||||
return process_packet(packet, *qdata);
|
||||
}
|
||||
|
||||
#define BUF_SIZE (0xffff + (MNL_SOCKET_BUFFER_SIZE / 2))
|
||||
|
||||
int init_queue(int queue_num) {
|
||||
struct mnl_socket *nl;
|
||||
|
||||
@ -791,14 +477,7 @@ int init_queue(int queue_num) {
|
||||
uint32_t portid = mnl_socket_get_portid(nl);
|
||||
|
||||
struct nlmsghdr *nlh;
|
||||
char *buf;
|
||||
size_t buf_size = 0xffff + (MNL_SOCKET_BUFFER_SIZE / 2);
|
||||
buf = malloc(buf_size);
|
||||
if (!buf) {
|
||||
perror("Allocate recieve buffer");
|
||||
goto die_sock;
|
||||
}
|
||||
|
||||
char buf[BUF_SIZE];
|
||||
|
||||
nlh = nfq_nlmsg_put(buf, NFQNL_MSG_CONFIG, queue_num);
|
||||
nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_BIND);
|
||||
@ -837,7 +516,7 @@ int init_queue(int queue_num) {
|
||||
printf("Queue %d started!\n", qdata.queue_num);
|
||||
|
||||
while (1) {
|
||||
ret = mnl_socket_recvfrom(nl, buf, buf_size);
|
||||
ret = mnl_socket_recvfrom(nl, buf, BUF_SIZE);
|
||||
if (ret == -1) {
|
||||
perror("mnl_socket_recvfrom");
|
||||
continue;
|
||||
@ -850,13 +529,10 @@ int init_queue(int queue_num) {
|
||||
}
|
||||
|
||||
|
||||
free(buf);
|
||||
close_socket(&nl);
|
||||
return 0;
|
||||
|
||||
die:
|
||||
free(buf);
|
||||
die_sock:
|
||||
close_socket(&nl);
|
||||
return -1;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user