zapret/nfq/nfqws.c
2022-01-03 12:38:18 +03:00

1009 lines
28 KiB
C

#define _GNU_SOURCE
#include "nfqws.h"
#include "sec.h"
#include "desync.h"
#include "helpers.h"
#include "checksum.h"
#include "params.h"
#include "protocol.h"
#include "hostlist.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdint.h>
#include <arpa/inet.h>
#include <getopt.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#ifdef __linux__
#include <libnetfilter_queue/libnetfilter_queue.h>
#define NF_DROP 0
#define NF_ACCEPT 1
#endif
#ifndef IPPROTO_DIVERT
#define IPPROTO_DIVERT 258
#endif
#define CTRACK_T_SYN 60
#define CTRACK_T_FIN 60
#define CTRACK_T_EST 300
#define CTRACK_T_UDP 60
struct params_s params;
static bool bHup = false;
static void onhup(int sig)
{
printf("HUP received !\n");
if (params.hostlist)
printf("Will reload hostlist on next request\n");
bHup = true;
}
// should be called in normal execution
static void dohup()
{
if (bHup)
{
if (params.hostlist)
{
if (!LoadHostList(&params.hostlist, params.hostfile))
{
// what will we do without hostlist ?? sure, gonna die
exit(1);
}
}
bHup = false;
}
}
static void onusr1(int sig)
{
printf("\nCONNTRACK DUMP\n");
ConntrackPoolDump(&params.conntrack);
printf("\n");
}
#ifdef __linux__
static packet_process_result processPacketData(uint8_t *data_pkt, size_t len_pkt, uint32_t *mark)
#else
static packet_process_result processPacketData(uint8_t *data_pkt, size_t len_pkt)
#endif
{
struct ip *ip = NULL;
struct ip6_hdr *ip6hdr = NULL;
struct tcphdr *tcphdr = NULL;
struct udphdr *udphdr = NULL;
size_t len = len_pkt, len_with_th;
uint8_t *data = data_pkt;
packet_process_result res = pass;
uint8_t proto;
#ifdef __linux__
if (*mark & params.desync_fwmark)
{
DLOG("ignoring generated packet\n")
return res;
}
#endif
if (proto_check_ipv4(data, len))
{
ip = (struct ip *) data;
proto = ip->ip_p;
proto_skip_ipv4(&data, &len);
if (params.debug)
{
printf("IP4: ");
print_ip(ip);
}
}
else if (proto_check_ipv6(data, len))
{
ip6hdr = (struct ip6_hdr *) data;
proto_skip_ipv6(&data, &len, &proto);
if (params.debug)
{
printf("IP6: ");
print_ip6hdr(ip6hdr, proto);
}
}
else
{
// not ipv6 and not ipv4
return res;
}
if (proto==IPPROTO_TCP && proto_check_tcp(data, len))
{
tcphdr = (struct tcphdr *) data;
len_with_th = len;
proto_skip_tcp(&data, &len);
if (params.debug)
{
printf(" ");
print_tcphdr(tcphdr);
printf("\n");
}
if (len) { DLOG("TCP: ") hexdump_limited_dlog(data, len, 32); DLOG("\n") }
res = dpi_desync_tcp_packet(data_pkt, len_pkt, ip, ip6hdr, tcphdr, len_with_th, data, len);
// in my FreeBSD divert tests only ipv4 packets were reinjected with correct checksum
// ipv6 packets were with incorrect checksum
#ifdef __FreeBSD__
// FreeBSD tend to pass ipv6 frames with wrong checksum
if (res==modify || res!=frag && ip6hdr)
#else
if (res==modify)
#endif
tcp_fix_checksum(tcphdr,len_with_th,ip,ip6hdr);
}
else if (proto==IPPROTO_UDP && proto_check_udp(data, len))
{
udphdr = (struct udphdr *) data;
len_with_th = len;
proto_skip_udp(&data, &len);
if (params.debug)
{
printf(" ");
print_udphdr(udphdr);
printf("\n");
}
if (len) { DLOG("UDP: ") hexdump_limited_dlog(data, len, 32); DLOG("\n") }
res = dpi_desync_udp_packet(data_pkt, len_pkt, ip, ip6hdr, udphdr, data, len);
#ifdef __FreeBSD__
// FreeBSD tend to pass ipv6 frames with wrong checksum
if (res==modify || res!=frag && ip6hdr)
#else
if (res==modify)
#endif
udp_fix_checksum(udphdr,len_with_th,ip,ip6hdr);
}
else
{
if (params.debug) printf("\n");
}
return res;
}
#ifdef __linux__
static int nfq_cb(struct nfq_q_handle *qh, struct nfgenmsg *nfmsg,
struct nfq_data *nfa, void *cookie)
{
int id;
int len;
struct nfqnl_msg_packet_hdr *ph;
uint8_t *data;
ph = nfq_get_msg_packet_hdr(nfa);
id = ph ? ntohl(ph->packet_id) : 0;
uint32_t mark = nfq_get_nfmark(nfa);
len = nfq_get_payload(nfa, &data);
DLOG("packet: id=%d len=%d\n", id, len)
if (len >= 0)
{
switch (processPacketData(data, len, &mark))
{
case modify:
DLOG("packet: id=%d pass modified\n", id);
return nfq_set_verdict2(qh, id, NF_ACCEPT, mark, len, data);
case drop:
case frag:
DLOG("packet: id=%d drop\n", id);
return nfq_set_verdict2(qh, id, NF_DROP, mark, 0, NULL);
}
}
DLOG("packet: id=%d pass unmodified\n", id);
return nfq_set_verdict2(qh, id, NF_ACCEPT, mark, 0, NULL);
}
static int nfq_main()
{
struct nfq_handle *h = NULL;
struct nfq_q_handle *qh = NULL;
int fd,rv;
uint8_t buf[16384] __attribute__((aligned));
printf("opening library handle\n");
h = nfq_open();
if (!h) {
perror("nfq_open()");
goto exiterr;
}
printf("unbinding existing nf_queue handler for AF_INET (if any)\n");
if (nfq_unbind_pf(h, AF_INET) < 0) {
perror("nfq_unbind_pf()");
goto exiterr;
}
printf("binding nfnetlink_queue as nf_queue handler for AF_INET\n");
if (nfq_bind_pf(h, AF_INET) < 0) {
perror("nfq_bind_pf()");
goto exiterr;
}
printf("binding this socket to queue '%u'\n", params.qnum);
qh = nfq_create_queue(h, params.qnum, &nfq_cb, &params);
if (!qh) {
perror("nfq_create_queue()");
goto exiterr;
}
printf("setting copy_packet mode\n");
if (nfq_set_mode(qh, NFQNL_COPY_PACKET, 0xffff) < 0) {
perror("can't set packet_copy mode");
goto exiterr;
}
if (nfq_set_queue_maxlen(qh, Q_MAXLEN) < 0) {
perror("can't set queue maxlen");
goto exiterr;
}
// accept packets if they cant be handled
if (nfq_set_queue_flags(qh, NFQA_CFG_F_FAIL_OPEN , NFQA_CFG_F_FAIL_OPEN))
{
fprintf(stderr, "can't set queue flags. its OK on linux <3.6\n");
// dot not fail. not supported on old linuxes <3.6
}
if (params.droproot && !droproot(params.uid, params.gid))
goto exiterr;
print_id();
signal(SIGHUP, onhup);
signal(SIGUSR1, onusr1);
desync_init();
fd = nfq_fd(h);
// increase socket buffer size. on slow systems reloading hostlist can take a while.
// if too many unhandled packets are received its possible to get "no buffer space available" error
if (!set_socket_buffers(fd,Q_RCVBUF/2,Q_SNDBUF/2))
goto exiterr;
do
{
while ((rv = recv(fd, buf, sizeof(buf), 0)) > 0)
{
dohup();
int r = nfq_handle_packet(h, buf, rv);
if (r) fprintf(stderr, "nfq_handle_packet error %d\n", r);
}
fprintf(stderr, "recv: errno %d\n",errno);
perror("recv");
// do not fail on ENOBUFS
} while(errno==ENOBUFS);
printf("unbinding from queue %u\n", params.qnum);
nfq_destroy_queue(qh);
#ifdef INSANE
/* normally, applications SHOULD NOT issue this command, since
* it detaches other programs/sockets from AF_INET, too ! */
printf("unbinding from AF_INET\n");
nfq_unbind_pf(h, AF_INET);
#endif
printf("closing library handle\n");
nfq_close(h);
return 0;
exiterr:
if (qh) nfq_destroy_queue(qh);
if (h) nfq_close(h);
return 1;
}
#elif defined(BSD)
static int dvt_main()
{
uint8_t buf[16384] __attribute__((aligned));
struct sockaddr_storage sa_from;
int fd[2] = {-1,-1}; // 4,6
int i,r,res=1,fdct=1,fdmax;
unsigned int id=0;
socklen_t socklen;
ssize_t rd,wr;
packet_process_result ppr;
fd_set fdset;
{
struct sockaddr_in bp4;
bp4.sin_family = AF_INET;
bp4.sin_port = htons(params.port);
bp4.sin_addr.s_addr = INADDR_ANY;
printf("creating divert4 socket\n");
fd[0] = socket(AF_INET, SOCK_RAW, IPPROTO_DIVERT);
if (fd[0] == -1) {
perror("socket (DIVERT4)");
goto exiterr;
}
printf("binding divert4 socket\n");
if (bind(fd[0], (struct sockaddr*)&bp4, sizeof(bp4)) < 0)
{
perror("bind (DIVERT4)");
goto exiterr;
}
if (!set_socket_buffers(fd[0],Q_RCVBUF,Q_SNDBUF))
goto exiterr;
}
#ifdef __OpenBSD__
{
// in OpenBSD must use separate divert sockets for ipv4 and ipv6
struct sockaddr_in6 bp6;
memset(&bp6,0,sizeof(bp6));
bp6.sin6_family = AF_INET6;
bp6.sin6_port = htons(params.port);
printf("creating divert6 socket\n");
fd[1] = socket(AF_INET6, SOCK_RAW, IPPROTO_DIVERT);
if (fd[1] == -1) {
perror("socket (DIVERT6)");
goto exiterr;
}
printf("binding divert6 socket\n");
if (bind(fd[1], (struct sockaddr*)&bp6, sizeof(bp6)) < 0)
{
perror("bind (DIVERT6)");
goto exiterr;
}
fdct++;
if (!set_socket_buffers(fd[1],Q_RCVBUF,Q_SNDBUF))
goto exiterr;
}
#endif
fdmax = (fd[0]>fd[1] ? fd[0] : fd[1]) + 1;
printf("initializing raw sockets with sockarg 0x%08X (%u)\n", params.desync_fwmark, params.desync_fwmark);
if (!rawsend_preinit(params.desync_fwmark))
goto exiterr;
if (params.droproot && !droproot(params.uid, params.gid))
goto exiterr;
print_id();
signal(SIGHUP, onhup);
signal(SIGUSR1, onusr1);
desync_init();
for(;;)
{
FD_ZERO(&fdset);
for(i=0;i<fdct;i++) FD_SET(fd[i], &fdset);
r = select(fdmax,&fdset,NULL,NULL,NULL);
if (r==-1)
{
if (errno==EINTR)
{
// a signal received
dohup();
continue;
}
perror("select");
goto exiterr;
}
for(i=0;i<fdct;i++)
{
if (FD_ISSET(fd[i], &fdset))
{
socklen = sizeof(sa_from);
rd = recvfrom(fd[i], buf, sizeof(buf), 0, (struct sockaddr*)&sa_from, &socklen);
if (rd<0)
{
perror("recvfrom");
goto exiterr;
}
else if (rd>0)
{
DLOG("packet: id=%u len=%zd\n", id, rd)
ppr = processPacketData(buf, rd);
switch (ppr)
{
case pass:
case modify:
DLOG(ppr==pass ? "packet: id=%u reinject unmodified\n" : "packet: id=%u reinject modified\n", id);
wr = sendto(fd[i], buf, rd, 0, (struct sockaddr*)&sa_from, socklen);
if (wr<0)
perror("reinject sendto");
else if (wr!=rd)
fprintf(stderr,"reinject sendto: not all data was reinjected. received %zd, sent %zd\n", rd, wr);
break;
default:
DLOG("packet: id=%u drop\n", id);
}
id++;
}
else
{
DLOG("unexpected zero size recvfrom\n")
}
}
}
}
res=0;
exiterr:
if (fd[0]!=-1) close(fd[0]);
if (fd[1]!=-1) close(fd[1]);
return res;
}
#endif
static bool parse_ws_scale_factor(char *s, uint16_t *wsize, uint8_t *wscale)
{
int v;
char *p;
if ((p = strchr(s,':'))) *p++=0;
v = atoi(s);
if (v < 0 || v>65535)
{
fprintf(stderr, "bad wsize\n");
return false;
}
*wsize=(uint16_t)v;
if (p && *p)
{
v = atoi(p);
if (v < 0 || v>255)
{
fprintf(stderr, "bad wscale\n");
return false;
}
*wscale = (uint8_t)v;
}
return true;
}
static void exithelp()
{
printf(
" --debug=0|1\n"
#ifdef __linux__
" --qnum=<nfqueue_number>\n"
#elif defined(BSD)
" --port=<port>\t\t\t\t; divert port\n"
#endif
" --daemon\t\t\t\t; daemonize\n"
" --pidfile=<filename>\t\t\t; write pid to file\n"
" --user=<username>\t\t\t; drop root privs\n"
" --uid=uid[:gid]\t\t\t; drop root privs\n"
" --wsize=<window_size>[:<scale_factor>]\t; set window size. 0 = do not modify. OBSOLETE !\n"
" --wssize=<window_size>[:<scale_factor>]; set window size for server. 0 = do not modify. default scale_factor = 0.\n"
" --wssize-cutoff=[n|d|s]N\t\t; apply server wsize only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
" --ctrack-timeouts=S:E:F[:U]\t\t; internal conntrack timeouts for TCP SYN, ESTABLISHED, FIN stages, UDP timeout. default %u:%u:%u:%u\n"
" --hostcase\t\t\t\t; change Host: => host:\n"
" --hostspell\t\t\t\t; exact spelling of \"Host\" header. must be 4 chars. default is \"host\"\n"
" --hostnospace\t\t\t\t; remove space after Host: and add it to User-Agent: to preserve packet size\n"
" --domcase\t\t\t\t; mix domain case : Host: TeSt.cOm\n"
" --dpi-desync=[<mode0>,]<mode>[,<mode2>] ; try to desync dpi state. modes : synack fake rst rstack disorder disorder2 split split2 ipfrag2\n"
#ifdef __linux__
" --dpi-desync-fwmark=<int|0xHEX>\t; override fwmark for desync packet. default = 0x%08X (%u)\n"
#elif defined(SO_USER_COOKIE)
" --dpi-desync-sockarg=<int|0xHEX>\t; override sockarg (SO_USER_COOKIE) for desync packet. default = 0x%08X (%u)\n"
#endif
" --dpi-desync-ttl=<int>\t\t\t; set ttl for desync packet\n"
" --dpi-desync-ttl6=<int>\t\t; set ipv6 hop limit for desync packet. by default ttl value is used.\n"
" --dpi-desync-fooling=<mode>[,<mode>]\t; can use multiple comma separated values. modes : none md5sig ts badseq badsum\n"
#ifdef __linux__
" --dpi-desync-retrans=0|1\t\t; 0(default)=reinject original data packet after fake 1=drop original data packet to force its retransmission\n"
#endif
" --dpi-desync-repeats=<N>\t\t; send every desync packet N times\n"
" --dpi-desync-skip-nosni=0|1\t\t; 1(default)=do not act on ClientHello without SNI (ESNI ?)\n"
" --dpi-desync-split-pos=<1..%u>\t; data payload split position\n"
" --dpi-desync-ipfrag-pos-tcp=<8..%u>\t; ip frag position starting from the second header (usually transport header). multiple of 8, default %u.\n"
" --dpi-desync-ipfrag-pos-udp=<8..%u>\t; ip frag position starting from the second header (usually transport header). multiple of 8, default %u.\n"
" --dpi-desync-badseq-increment=<int|0xHEX> ; badseq fooling seq signed increment. default %d\n"
" --dpi-desync-badack-increment=<int|0xHEX> ; badseq fooling ackseq signed increment. default %d\n"
" --dpi-desync-any-protocol=0|1\t\t; 0(default)=desync only http and tls 1=desync any nonempty data packet\n"
" --dpi-desync-fake-http=<filename>\t; file containing fake http request\n"
" --dpi-desync-fake-tls=<filename>\t; file containing fake TLS ClientHello (for https)\n"
" --dpi-desync-fake-unknown=<filename>\t; file containing unknown protocol fake payload\n"
" --dpi-desync-fake-unknown-udp=<filename> ; file containing unknown udp protocol fake payload\n"
" --dpi-desync-cutoff=[n|d|s]N\t\t; apply dpi desync only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
" --hostlist=<filename>\t\t\t; apply dpi desync only to the listed hosts (one host per line, subdomains auto apply)\n",
CTRACK_T_SYN, CTRACK_T_EST, CTRACK_T_FIN, CTRACK_T_UDP,
#if defined(__linux__) || defined(SO_USER_COOKIE)
DPI_DESYNC_FWMARK_DEFAULT,DPI_DESYNC_FWMARK_DEFAULT,
#endif
DPI_DESYNC_MAX_FAKE_LEN,
DPI_DESYNC_MAX_FAKE_LEN, IPFRAG_UDP_DEFAULT,
DPI_DESYNC_MAX_FAKE_LEN, IPFRAG_TCP_DEFAULT,
BADSEQ_INCREMENT_DEFAULT, BADSEQ_ACK_INCREMENT_DEFAULT
);
exit(1);
}
static void cleanup_params()
{
if (params.hostlist)
{
StrPoolDestroy(&params.hostlist);
params.hostlist = NULL;
}
ConntrackPoolDestroy(&params.conntrack);
}
static void exithelp_clean()
{
cleanup_params();
exithelp();
}
static void exit_clean(int code)
{
cleanup_params();
exit(code);
}
static bool parse_cutoff(const char *opt, unsigned int *value, char *mode)
{
*mode = (*opt=='n' || *opt=='d' || *opt=='s') ? *opt++ : 'n';
return sscanf(opt, "%u", value)>0;
}
static bool parse_badseq_increment(const char *opt, uint32_t *value)
{
if ((opt[0]=='0' && opt[1]=='x' || opt[0]=='-' && opt[1]=='0' && opt[2]=='x') && sscanf(opt+2+(opt[0]=='-'), "%X", (int32_t*)value)>0)
{
if (opt[0]=='-') params.desync_badseq_increment = -params.desync_badseq_increment;
return true;
}
else
{
return sscanf(opt, "%d", (int32_t*)value)>0;
}
}
static void load_file_or_exit(const char *filename, void *buf, size_t *size)
{
if (!load_file_nonempty(filename,buf,size))
{
fprintf(stderr, "could not read %s\n",filename);
exit_clean(1);
}
DLOG("read %zu bytes from %s\n",*size,filename)
}
int main(int argc, char **argv)
{
int result, v;
int option_index = 0;
bool daemon = false;
char pidfile[256];
srandom(time(NULL));
memset(&params, 0, sizeof(params));
memcpy(params.hostspell, "host", 4); // default hostspell
*pidfile = 0;
params.desync_fwmark = DPI_DESYNC_FWMARK_DEFAULT;
params.desync_skip_nosni = true;
params.desync_split_pos = 2;
params.desync_ipfrag_pos_udp = IPFRAG_UDP_DEFAULT;
params.desync_ipfrag_pos_tcp = IPFRAG_TCP_DEFAULT;
params.desync_repeats = 1;
params.fake_tls_size = sizeof(fake_tls_clienthello_default);
memcpy(params.fake_tls,fake_tls_clienthello_default,params.fake_tls_size);
params.fake_http_size = strlen(fake_http_request_default);
memcpy(params.fake_http,fake_http_request_default,params.fake_http_size);
params.fake_unknown_size = 256;
params.fake_unknown_udp_size = 64;
params.wscale=-1; // default - dont change scale factor (client)
params.ctrack_t_syn = CTRACK_T_SYN;
params.ctrack_t_est = CTRACK_T_EST;
params.ctrack_t_fin = CTRACK_T_FIN;
params.ctrack_t_udp = CTRACK_T_UDP;
params.desync_ttl6 = 0xFF; // unused
params.desync_badseq_increment = BADSEQ_INCREMENT_DEFAULT;
params.desync_badseq_ack_increment = BADSEQ_ACK_INCREMENT_DEFAULT;
params.wssize_cutoff_mode = params.desync_cutoff_mode = 'n'; // packet number by default
if (can_drop_root()) // are we root ?
{
params.uid = params.gid = 0x7FFFFFFF; // default uid:gid
params.droproot = true;
}
const struct option long_options[] = {
{"debug",optional_argument,0,0}, // optidx=0
#ifdef __linux__
{"qnum",required_argument,0,0}, // optidx=1
#elif defined(BSD)
{"port",required_argument,0,0}, // optidx=1
#else
{"disabled_argument_1",no_argument,0,0},// optidx=1
#endif
{"daemon",no_argument,0,0}, // optidx=2
{"pidfile",required_argument,0,0}, // optidx=3
{"user",required_argument,0,0 }, // optidx=4
{"uid",required_argument,0,0 }, // optidx=5
{"wsize",required_argument,0,0}, // optidx=6
{"wssize",required_argument,0,0}, // optidx=7
{"wssize-cutoff",required_argument,0,0},// optidx=8
{"ctrack-timeouts",required_argument,0,0},// optidx=9
{"hostcase",no_argument,0,0}, // optidx=10
{"hostspell",required_argument,0,0}, // optidx=11
{"hostnospace",no_argument,0,0}, // optidx=12
{"domcase",no_argument,0,0 }, // optidx=13
{"dpi-desync",required_argument,0,0}, // optidx=14
#ifdef __linux__
{"dpi-desync-fwmark",required_argument,0,0}, // optidx=15
#elif defined(SO_USER_COOKIE)
{"dpi-desync-sockarg",required_argument,0,0}, // optidx=15
#else
{"disabled_argument_2",no_argument,0,0}, // optidx=15
#endif
{"dpi-desync-ttl",required_argument,0,0}, // optidx=16
{"dpi-desync-ttl6",required_argument,0,0}, // optidx=17
{"dpi-desync-fooling",required_argument,0,0}, // optidx=18
{"dpi-desync-retrans",optional_argument,0,0}, // optidx=19
{"dpi-desync-repeats",required_argument,0,0}, // optidx=20
{"dpi-desync-skip-nosni",optional_argument,0,0},// optidx=21
{"dpi-desync-split-pos",required_argument,0,0},// optidx=22
{"dpi-desync-ipfrag-pos-tcp",required_argument,0,0},// optidx=24
{"dpi-desync-ipfrag-pos-udp",required_argument,0,0},// optidx=25
{"dpi-desync-badseq-increment",required_argument,0,0},// optidx=26
{"dpi-desync-badack-increment",required_argument,0,0},// optidx=27
{"dpi-desync-any-protocol",optional_argument,0,0},// optidx=28
{"dpi-desync-fake-http",required_argument,0,0},// optidx=29
{"dpi-desync-fake-tls",required_argument,0,0},// optidx=30
{"dpi-desync-fake-unknown",required_argument,0,0},// optidx=31
{"dpi-desync-fake-unknown-udp",required_argument,0,0},// optidx=32
{"dpi-desync-cutoff",required_argument,0,0},// optidx=33
{"hostlist",required_argument,0,0}, // optidx=34
{NULL,0,NULL,0}
};
if (argc < 2) exithelp();
while ((v = getopt_long_only(argc, argv, "", long_options, &option_index)) != -1)
{
if (v) exithelp();
switch (option_index)
{
case 0: /* debug */
params.debug = !optarg || atoi(optarg);
break;
case 1: /* qnum or port */
#ifdef __linux__
params.qnum = atoi(optarg);
if (params.qnum < 0 || params.qnum>65535)
{
fprintf(stderr, "bad qnum\n");
exit_clean(1);
}
#elif defined(BSD)
{
int i = atoi(optarg);
if (i <= 0 || i > 65535)
{
fprintf(stderr, "bad port number\n");
exit_clean(1);
}
params.port = (uint16_t)i;
}
#endif
break;
case 2: /* daemon */
daemon = true;
break;
case 3: /* pidfile */
strncpy(pidfile, optarg, sizeof(pidfile));
pidfile[sizeof(pidfile) - 1] = '\0';
break;
case 4: /* user */
{
struct passwd *pwd = getpwnam(optarg);
if (!pwd)
{
fprintf(stderr, "non-existent username supplied\n");
exit_clean(1);
}
params.uid = pwd->pw_uid;
params.gid = pwd->pw_gid;
params.droproot = true;
break;
}
case 5: /* uid */
params.gid = 0x7FFFFFFF; // default gid. drop gid=0
params.droproot = true;
if (sscanf(optarg, "%u:%u", &params.uid, &params.gid)<1)
{
fprintf(stderr, "--uid should be : uid[:gid]\n");
exit_clean(1);
}
break;
case 6: /* wsize */
if (!parse_ws_scale_factor(optarg,&params.wsize,&params.wscale))
exit_clean(1);
break;
case 7: /* wssize */
if (!parse_ws_scale_factor(optarg,&params.wssize,&params.wsscale))
exit_clean(1);
break;
case 8: /* wssize-cutoff */
if (!parse_cutoff(optarg, &params.wssize_cutoff, &params.wssize_cutoff_mode))
{
fprintf(stderr, "invalid wssize-cutoff value\n");
exit_clean(1);
}
break;
case 9: /* ctrack-timeouts */
if (sscanf(optarg, "%u:%u:%u:%u", &params.ctrack_t_syn, &params.ctrack_t_est, &params.ctrack_t_fin, &params.ctrack_t_udp)<3)
{
fprintf(stderr, "invalid ctrack-timeouts value\n");
exit_clean(1);
}
break;
case 10: /* hostcase */
params.hostcase = true;
break;
case 11: /* hostspell */
if (strlen(optarg) != 4)
{
fprintf(stderr, "hostspell must be exactly 4 chars long\n");
exit_clean(1);
}
params.hostcase = true;
memcpy(params.hostspell, optarg, 4);
break;
case 12: /* hostnospace */
params.hostnospace = true;
break;
case 13: /* domcase */
params.domcase = true;
break;
case 14: /* dpi-desync */
{
char *mode=optarg,*mode2,*mode3;
mode2 = mode ? strchr(mode,',') : NULL;
if (mode2) *mode2++=0;
mode3 = mode2 ? strchr(mode2,',') : NULL;
if (mode3) *mode3++=0;
params.desync_mode0 = desync_mode_from_string(mode);
if (desync_valid_zero_stage(params.desync_mode0))
{
mode = mode2;
mode2 = mode3;
mode3 = NULL;
}
else
{
params.desync_mode0 = DESYNC_NONE;
}
params.desync_mode = desync_mode_from_string(mode);
params.desync_mode2 = desync_mode_from_string(mode2);
if (params.desync_mode0==DESYNC_INVALID || params.desync_mode==DESYNC_INVALID || params.desync_mode2==DESYNC_INVALID)
{
fprintf(stderr, "invalid dpi-desync mode\n");
exit_clean(1);
}
if (mode3)
{
fprintf(stderr, "invalid desync combo : %s+%s+%s\n",mode,mode2,mode3);
exit_clean(1);
}
if (params.desync_mode2 && !(desync_valid_first_stage(params.desync_mode) && desync_valid_second_stage(params.desync_mode2)))
{
fprintf(stderr, "invalid desync combo : %s+%s\n", mode,mode2);
exit_clean(1);
}
#if defined(__OpenBSD__)
if (params.desync_mode==DESYNC_IPFRAG2 || params.desync_mode2==DESYNC_IPFRAG2)
{
fprintf(stderr, "OpenBSD has checksum issues with fragmented packets. ipfrag disabled.\n");
exit_clean(1);
}
#endif
}
break;
case 15: /* dpi-desync-fwmark/dpi-desync-sockarg */
#if defined(__linux__) || defined(SO_USER_COOKIE)
params.desync_fwmark = 0;
if (sscanf(optarg, "0x%X", &params.desync_fwmark)<=0) sscanf(optarg, "%u", &params.desync_fwmark);
if (!params.desync_fwmark)
{
fprintf(stderr, "fwmark/sockarg should be decimal or 0xHEX and should not be zero\n");
exit_clean(1);
}
#else
fprintf(stderr, "fmwark/sockarg not supported in this OS\n");
exit_clean(1);
#endif
break;
case 16: /* dpi-desync-ttl */
params.desync_ttl = (uint8_t)atoi(optarg);
break;
case 17: /* dpi-desync-ttl6 */
params.desync_ttl6 = (uint8_t)atoi(optarg);
break;
case 18: /* dpi-desync-fooling */
{
char *e,*p = optarg;
while (p)
{
e = strchr(p,',');
if (e) *e++=0;
if (!strcmp(p,"md5sig"))
params.desync_fooling_mode |= FOOL_MD5SIG;
else if (!strcmp(p,"ts"))
params.desync_fooling_mode |= FOOL_TS;
else if (!strcmp(p,"badsum"))
{
#ifdef __OpenBSD__
printf("\nWARNING !!! OpenBSD may forcibly recompute tcp/udp checksums !!! In this case badsum fooling will not work.\nYou should check tcp checksum correctness in tcpdump manually before using badsum.\n\n");
#endif
params.desync_fooling_mode |= FOOL_BADSUM;
}
else if (!strcmp(p,"badseq"))
params.desync_fooling_mode |= FOOL_BADSEQ;
else if (strcmp(p,"none"))
{
fprintf(stderr, "dpi-desync-fooling allowed values : none,md5sig,ts,badseq,badsum\n");
exit_clean(1);
}
p = e;
}
}
break;
case 19: /* dpi-desync-retrans */
#ifdef __linux__
params.desync_retrans = !optarg || atoi(optarg);
#else
fprintf(stderr, "dpi-desync-retrans is only supported in linux\n");
exit_clean(1);
#endif
break;
case 20: /* dpi-desync-repeats */
if (sscanf(optarg,"%u",&params.desync_repeats)<1 || params.desync_repeats<=0 || params.desync_repeats>20)
{
fprintf(stderr, "dpi-desync-repeats must be within 1..20\n");
exit_clean(1);
}
break;
case 21: /* dpi-desync-skip-nosni */
params.desync_skip_nosni = !optarg || atoi(optarg);
break;
case 22: /* dpi-desync-split-pos */
if (sscanf(optarg,"%u",&params.desync_split_pos)<1 || params.desync_split_pos<1 || params.desync_split_pos>DPI_DESYNC_MAX_FAKE_LEN)
{
fprintf(stderr, "dpi-desync-split-pos must be within 1..%u range\n",DPI_DESYNC_MAX_FAKE_LEN);
exit_clean(1);
}
break;
case 23: /* dpi-desync-ipfrag-pos-tcp */
if (sscanf(optarg,"%u",&params.desync_ipfrag_pos_tcp)<1 || params.desync_ipfrag_pos_tcp<1 || params.desync_ipfrag_pos_tcp>DPI_DESYNC_MAX_FAKE_LEN)
{
fprintf(stderr, "dpi-desync-ipfrag-pos-tcp must be within 1..%u range\n",DPI_DESYNC_MAX_FAKE_LEN);
exit_clean(1);
}
if (params.desync_ipfrag_pos_tcp & 7)
{
fprintf(stderr, "dpi-desync-ipfrag-pos-tcp must be multiple of 8\n");
exit_clean(1);
}
break;
case 24: /* dpi-desync-ipfrag-pos-udp */
if (sscanf(optarg,"%u",&params.desync_ipfrag_pos_udp)<1 || params.desync_ipfrag_pos_udp<1 || params.desync_ipfrag_pos_udp>DPI_DESYNC_MAX_FAKE_LEN)
{
fprintf(stderr, "dpi-desync-ipfrag-pos-udp must be within 1..%u range\n",DPI_DESYNC_MAX_FAKE_LEN);
exit_clean(1);
}
if (params.desync_ipfrag_pos_udp & 7)
{
fprintf(stderr, "dpi-desync-ipfrag-pos-udp must be multiple of 8\n");
exit_clean(1);
}
break;
case 25: /* dpi-desync-badseq-increments */
if (!parse_badseq_increment(optarg,&params.desync_badseq_increment))
{
fprintf(stderr, "dpi-desync-badseq-increment should be signed decimal or signed 0xHEX\n");
exit_clean(1);
}
break;
case 26: /* dpi-desync-badack-increment */
if (!parse_badseq_increment(optarg,&params.desync_badseq_ack_increment))
{
fprintf(stderr, "dpi-desync-badack-increment should be signed decimal or signed 0xHEX\n");
exit_clean(1);
}
break;
case 27: /* dpi-desync-any-protocol */
params.desync_any_proto = !optarg || atoi(optarg);
break;
case 28: /* dpi-desync-fake-http */
params.fake_http_size = sizeof(params.fake_http);
load_file_or_exit(optarg,params.fake_http,&params.fake_http_size);
break;
case 29: /* dpi-desync-fake-tls */
params.fake_tls_size = sizeof(params.fake_tls);
load_file_or_exit(optarg,params.fake_tls,&params.fake_tls_size);
break;
case 30: /* dpi-desync-fake-unknown */
params.fake_unknown_size = sizeof(params.fake_unknown);
load_file_or_exit(optarg,params.fake_unknown,&params.fake_unknown_size);
break;
case 31: /* dpi-desync-fake-unknown-udp */
params.fake_unknown_udp_size = sizeof(params.fake_unknown_udp);
load_file_or_exit(optarg,params.fake_unknown_udp,&params.fake_unknown_udp_size);
break;
case 32: /* desync-cutoff */
if (!parse_cutoff(optarg, &params.desync_cutoff, &params.desync_cutoff_mode))
{
fprintf(stderr, "invalid desync-cutoff value\n");
exit_clean(1);
}
break;
case 33: /* hostlist */
if (!LoadHostList(&params.hostlist, optarg))
exit_clean(1);
strncpy(params.hostfile,optarg,sizeof(params.hostfile));
params.hostfile[sizeof(params.hostfile)-1]='\0';
break;
}
}
// not specified - use desync_ttl value instead
if (params.desync_ttl6 == 0xFF) params.desync_ttl6=params.desync_ttl;
#ifdef BSD
if (!params.port)
{
fprintf(stderr, "Need port number\n");
exit_clean(1);
}
#endif
if (daemon) daemonize();
if (*pidfile && !writepid(pidfile))
{
fprintf(stderr, "could not write pidfile\n");
goto exiterr;
}
DLOG("initializing conntrack with timeouts tcp=%u:%u:%u udp=%u\n", params.ctrack_t_syn, params.ctrack_t_est, params.ctrack_t_fin, params.ctrack_t_udp)
ConntrackPoolInit(&params.conntrack, 10, params.ctrack_t_syn, params.ctrack_t_est, params.ctrack_t_fin, params.ctrack_t_udp);
#ifdef __linux__
result = nfq_main();
#elif defined(BSD)
result = dvt_main();
#else
#error unsupported OS
#endif
ex:
rawsend_cleanup();
cleanup_params();
return result;
exiterr:
result = 1;
goto ex;
}