zapret/tpws/tpws.c

909 lines
26 KiB
C

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/select.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <errno.h>
#include <stdbool.h>
#include <netinet/tcp.h>
#include <getopt.h>
#include <pwd.h>
#include <sys/resource.h>
#include <time.h>
#include "tpws.h"
#ifdef BSD
#include <sys/sysctl.h>
#endif
#include "tpws_conn.h"
#include "hostlist.h"
#include "params.h"
#include "sec.h"
#include "redirect.h"
#include "helpers.h"
struct params_s params;
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
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 int8_t block_sigpipe()
{
sigset_t sigset;
memset(&sigset, 0, sizeof(sigset));
//Get the old sigset, add SIGPIPE and update sigset
if (sigprocmask(SIG_BLOCK, NULL, &sigset) == -1) {
perror("sigprocmask (get)");
return -1;
}
if (sigaddset(&sigset, SIGPIPE) == -1) {
perror("sigaddset");
return -1;
}
if (sigprocmask(SIG_BLOCK, &sigset, NULL) == -1) {
perror("sigprocmask (set)");
return -1;
}
return 0;
}
static bool is_interface_online(const char *ifname)
{
struct ifreq ifr;
int sock;
if ((sock=socket(PF_INET, SOCK_DGRAM, IPPROTO_IP))==-1)
return false;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
ifr.ifr_name[IFNAMSIZ-1] = 0;
ioctl(sock, SIOCGIFFLAGS, &ifr);
close(sock);
return !!(ifr.ifr_flags & IFF_UP);
}
static void exithelp()
{
printf(
" --bind-addr=<v4_addr>|<v6_addr>; for v6 link locals append %%interface_name\n"
" --bind-iface4=<interface_name>\t; bind to the first ipv4 addr of interface\n"
" --bind-iface6=<interface_name>\t; bind to the first ipv6 addr of interface\n"
" --bind-linklocal=prefer|force\t; prefer or force ipv6 link local\n"
" --bind-wait-ifup=<sec>\t\t; wait for interface to appear and up\n"
" --bind-wait-ip=<sec>\t\t; after ifup wait for ip address to appear up to N seconds\n"
" --bind-wait-ip-linklocal=<sec>\t; accept only link locals first N seconds then any\n"
" --bind-wait-only\t\t; wait for bind conditions satisfaction then exit. return code 0 if success.\n"
" * multiple binds are supported. each bind-addr, bind-iface* start new bind\n"
" --port=<port>\t\t\t; only one port number for all binds is supported\n"
" --socks\t\t\t; implement socks4/5 proxy instead of transparent proxy\n"
" --no-resolve\t\t\t; disable socks5 remote dns ability (resolves are not async, they block all activity)\n"
" --local-rcvbuf=<bytes>\n"
" --local-sndbuf=<bytes>\n"
" --remote-rcvbuf=<bytes>\n"
" --remote-sndbuf=<bytes>\n"
" --skip-nodelay\t\t\t; do not set TCP_NODELAY option for outgoing connections (incompatible with split options)\n"
" --maxconn=<max_connections>\n"
#ifdef SPLICE_PRESENT
" --maxfiles=<max_open_files>\t; should be at least (X*connections+16), where X=6 in tcp proxy mode, X=4 in tampering mode\n"
#else
" --maxfiles=<max_open_files>\t; should be at least (connections*2+16)\n"
#endif
" --max-orphan-time=<sec>\t; if local leg sends something and closes and remote leg is still connecting then cancel connection attempt after N seconds\n"
" --daemon\t\t\t; daemonize\n"
" --pidfile=<filename>\t\t; write pid to file\n"
" --user=<username>\t\t; drop root privs\n"
" --uid=uid[:gid]\t\t; drop root privs\n"
" --debug=0|1|2\t\t\t; 0(default)=silent 1=verbose 2=debug\n"
"\nTAMPERING:\n"
" --hostlist=<filename>\t\t; only act on host in the list (one host per line, subdomains auto apply)\n"
" --split-http-req=method|host\n"
" --split-pos=<numeric_offset>\t; split at specified pos. split-http-req takes precedence for http.\n"
" --split-any-protocol\t\t; split not only http and https\n"
" --hostcase\t\t\t; change Host: => host:\n"
" --hostspell\t\t\t; exact spelling of \"Host\" header. must be 4 chars. default is \"host\"\n"
" --hostdot\t\t\t; add \".\" after Host: name\n"
" --hosttab\t\t\t; add tab after Host: name\n"
" --hostnospace\t\t\t; remove space after Host:\n"
" --hostpad=<bytes>\t\t; add dummy padding headers before Host:\n"
" --domcase\t\t\t; mix domain case : Host: TeSt.cOm\n"
" --methodspace\t\t\t; add extra space after method\n"
" --methodeol\t\t\t; add end-of-line before method\n"
" --unixeol\t\t\t; replace 0D0A to 0A\n"
);
exit(1);
}
static void cleanup_params()
{
if (params.hostlist)
{
StrPoolDestroy(&params.hostlist);
params.hostlist = NULL;
}
}
static void exithelp_clean()
{
cleanup_params();
exithelp();
}
static void exit_clean(int code)
{
cleanup_params();
exit(code);
}
static void nextbind_clean()
{
params.binds_last++;
if (params.binds_last>=MAX_BINDS)
{
fprintf(stderr,"maximum of %d binds are supported\n",MAX_BINDS);
exit_clean(1);
}
}
static void checkbind_clean()
{
if (params.binds_last<0)
{
fprintf(stderr,"start new bind with --bind-addr,--bind-iface*\n");
exit_clean(1);
}
}
void parse_params(int argc, char *argv[])
{
int option_index = 0;
int v, i;
memset(&params, 0, sizeof(params));
memcpy(params.hostspell, "host", 4); // default hostspell
params.maxconn = DEFAULT_MAX_CONN;
params.max_orphan_time = DEFAULT_MAX_ORPHAN_TIME;
params.binds_last = -1;
if (can_drop_root())
{
params.uid = params.gid = 0x7FFFFFFF; // default uid:gid
params.droproot = true;
}
const struct option long_options[] = {
{ "help",no_argument,0,0 },// optidx=0
{ "h",no_argument,0,0 },// optidx=1
{ "bind-addr",required_argument,0,0 },// optidx=2
{ "bind-iface4",required_argument,0,0 },// optidx=3
{ "bind-iface6",required_argument,0,0 },// optidx=4
{ "bind-linklocal",required_argument,0,0 },// optidx=5
{ "bind-wait-ifup",required_argument,0,0 },// optidx=6
{ "bind-wait-ip",required_argument,0,0 },// optidx=7
{ "bind-wait-ip-linklocal",required_argument,0,0 },// optidx=8
{ "bind-wait-only",no_argument,0,0 },// optidx=9
{ "port",required_argument,0,0 },// optidx=10
{ "daemon",no_argument,0,0 },// optidx=11
{ "user",required_argument,0,0 },// optidx=12
{ "uid",required_argument,0,0 },// optidx=13
{ "maxconn",required_argument,0,0 },// optidx=14
{ "maxfiles",required_argument,0,0 },// optidx=15
{ "max-orphan-time",required_argument,0,0 },// optidx=16
{ "hostcase",no_argument,0,0 },// optidx=17
{ "hostspell",required_argument,0,0 },// optidx=18
{ "hostdot",no_argument,0,0 },// optidx=19
{ "hostnospace",no_argument,0,0 },// optidx=20
{ "hostpad",required_argument,0,0 },// optidx=21
{ "domcase",no_argument,0,0 },// optidx=22
{ "split-http-req",required_argument,0,0 },// optidx=23
{ "split-pos",required_argument,0,0 },// optidx=24
{ "split-any-protocol",optional_argument,0,0},// optidx=25
{ "methodspace",no_argument,0,0 },// optidx=26
{ "methodeol",no_argument,0,0 },// optidx=27
{ "hosttab",no_argument,0,0 },// optidx=28
{ "unixeol",no_argument,0,0 },// optidx=29
{ "hostlist",required_argument,0,0 },// optidx=30
{ "pidfile",required_argument,0,0 },// optidx=31
{ "debug",optional_argument,0,0 },// optidx=32
{ "local-rcvbuf",required_argument,0,0 },// optidx=33
{ "local-sndbuf",required_argument,0,0 },// optidx=34
{ "remote-rcvbuf",required_argument,0,0 },// optidx=35
{ "remote-sndbuf",required_argument,0,0 },// optidx=36
{ "socks",no_argument,0,0 },// optidx=37
{ "no-resolve",no_argument,0,0 },// optidx=38
{ "skip-nodelay",no_argument,0,0 },// optidx=39
{ NULL,0,NULL,0 }
};
while ((v = getopt_long_only(argc, argv, "", long_options, &option_index)) != -1)
{
if (v) exithelp_clean();
switch (option_index)
{
case 0:
case 1:
exithelp_clean();
break;
case 2: /* bind-addr */
nextbind_clean();
{
char *p = strchr(optarg,'%');
if (p)
{
*p=0;
strncpy(params.binds[params.binds_last].bindiface, p+1, sizeof(params.binds[params.binds_last].bindiface));
}
strncpy(params.binds[params.binds_last].bindaddr, optarg, sizeof(params.binds[params.binds_last].bindaddr));
}
params.binds[params.binds_last].bindaddr[sizeof(params.binds[params.binds_last].bindaddr) - 1] = 0;
break;
case 3: /* bind-iface4 */
nextbind_clean();
params.binds[params.binds_last].bind_if6=false;
strncpy(params.binds[params.binds_last].bindiface, optarg, sizeof(params.binds[params.binds_last].bindiface));
params.binds[params.binds_last].bindiface[sizeof(params.binds[params.binds_last].bindiface) - 1] = 0;
break;
case 4: /* bind-iface6 */
nextbind_clean();
params.binds[params.binds_last].bind_if6=true;
strncpy(params.binds[params.binds_last].bindiface, optarg, sizeof(params.binds[params.binds_last].bindiface));
params.binds[params.binds_last].bindiface[sizeof(params.binds[params.binds_last].bindiface) - 1] = 0;
break;
case 5: /* bind-linklocal */
checkbind_clean();
params.binds[params.binds_last].bindll = true;
if (!strcmp(optarg, "force"))
params.binds[params.binds_last].bindll_force=true;
else if (strcmp(optarg, "prefer"))
{
fprintf(stderr, "invalid parameter in bind-linklocal : %s\n",optarg);
exit_clean(1);
}
break;
case 6: /* bind-wait-ifup */
checkbind_clean();
params.binds[params.binds_last].bind_wait_ifup = atoi(optarg);
break;
case 7: /* bind-wait-ip */
checkbind_clean();
params.binds[params.binds_last].bind_wait_ip = atoi(optarg);
break;
case 8: /* bind-wait-ip-linklocal */
checkbind_clean();
params.binds[params.binds_last].bind_wait_ip_ll = atoi(optarg);
break;
case 9: /* bind-wait-only */
params.bind_wait_only = true;
break;
case 10: /* port */
i = atoi(optarg);
if (i <= 0 || i > 65535)
{
fprintf(stderr, "bad port number\n");
exit_clean(1);
}
params.port = (uint16_t)i;
break;
case 11: /* daemon */
params.daemon = true;
break;
case 12: /* 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 13: /* uid */
params.gid=0x7FFFFFFF; // default git. drop gid=0
params.droproot = true;
if (!sscanf(optarg,"%u:%u",&params.uid,&params.gid))
{
fprintf(stderr, "--uid should be : uid[:gid]\n");
exit_clean(1);
}
break;
case 14: /* maxconn */
params.maxconn = atoi(optarg);
if (params.maxconn <= 0 || params.maxconn > 10000)
{
fprintf(stderr, "bad maxconn\n");
exit_clean(1);
}
break;
case 15: /* maxfiles */
params.maxfiles = atoi(optarg);
if (params.maxfiles < 0)
{
fprintf(stderr, "bad maxfiles\n");
exit_clean(1);
}
break;
case 16: /* max-orphan-time */
params.max_orphan_time = atoi(optarg);
if (params.max_orphan_time < 0)
{
fprintf(stderr, "bad max_orphan_time\n");
exit_clean(1);
}
break;
case 17: /* hostcase */
params.hostcase = true;
params.tamper = true;
break;
case 18: /* 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);
params.tamper = true;
break;
case 19: /* hostdot */
params.hostdot = true;
params.tamper = true;
break;
case 20: /* hostnospace */
params.hostnospace = true;
params.tamper = true;
break;
case 21: /* hostpad */
params.hostpad = atoi(optarg);
params.tamper = true;
break;
case 22: /* domcase */
params.domcase = true;
params.tamper = true;
break;
case 23: /* split-http-req */
if (!strcmp(optarg, "method"))
params.split_http_req = split_method;
else if (!strcmp(optarg, "host"))
params.split_http_req = split_host;
else
{
fprintf(stderr, "Invalid argument for split-http-req\n");
exit_clean(1);
}
params.tamper = true;
break;
case 24: /* split-pos */
i = atoi(optarg);
if (i)
params.split_pos = i;
else
{
fprintf(stderr, "Invalid argument for split-pos\n");
exit_clean(1);
}
params.tamper = true;
break;
case 25: /* split-any-protocol */
params.split_any_protocol = true;
break;
case 26: /* methodspace */
params.methodspace = true;
params.tamper = true;
break;
case 27: /* methodeol */
params.methodeol = true;
params.tamper = true;
break;
case 28: /* hosttab */
params.hosttab = true;
params.tamper = true;
break;
case 29: /* unixeol */
params.unixeol = true;
params.tamper = true;
break;
case 30: /* hostlist */
if (!LoadHostList(&params.hostlist, optarg))
exit_clean(1);
strncpy(params.hostfile,optarg,sizeof(params.hostfile));
params.hostfile[sizeof(params.hostfile)-1]='\0';
params.tamper = true;
break;
case 31: /* pidfile */
strncpy(params.pidfile,optarg,sizeof(params.pidfile));
params.pidfile[sizeof(params.pidfile)-1]='\0';
break;
case 32:
params.debug = optarg ? atoi(optarg) : 1;
break;
case 33: /* local-rcvbuf */
params.local_rcvbuf = atoi(optarg)/2;
break;
case 34: /* local-sndbuf */
params.local_sndbuf = atoi(optarg)/2;
break;
case 35: /* remote-rcvbuf */
params.remote_rcvbuf = atoi(optarg)/2;
break;
case 36: /* remote-sndbuf */
params.remote_sndbuf = atoi(optarg)/2;
break;
case 37: /* socks */
params.proxy_type = CONN_TYPE_SOCKS;
break;
case 38: /* no-resolve */
params.no_resolve = true;
break;
case 39: /* skip-nodelay */
params.skip_nodelay = true;
break;
}
}
if (!params.bind_wait_only && !params.port)
{
fprintf(stderr, "Need port number\n");
exit_clean(1);
}
if (params.binds_last<=0)
{
params.binds_last=0; // default bind to all
}
if (params.skip_nodelay && (params.split_http_req || params.split_pos))
{
fprintf(stderr, "Cannot split with --skip-nodelay\n");
exit_clean(1);
}
}
static bool find_listen_addr(struct sockaddr_storage *salisten, const char *bindiface, bool bind_if6, bool bindll, int *if_index)
{
struct ifaddrs *addrs,*a;
bool found=false;
if (getifaddrs(&addrs)<0)
return false;
// ipv6 preference order
// bindll=1 : link-local
// bindll=0 : private,global,link-local
for(int pass=0;pass<3;pass++)
{
a = addrs;
while (a)
{
if (a->ifa_addr)
{
if (a->ifa_addr->sa_family==AF_INET &&
*bindiface && !bind_if6 && !strcmp(a->ifa_name, bindiface))
{
salisten->ss_family = AF_INET;
memcpy(&((struct sockaddr_in*)salisten)->sin_addr, &((struct sockaddr_in*)a->ifa_addr)->sin_addr, sizeof(struct in_addr));
found=true;
goto ex;
}
// ipv6 links locals are fe80::/10
else if (a->ifa_addr->sa_family==AF_INET6
&&
(!*bindiface && bindll ||
*bindiface && bind_if6 && !strcmp(a->ifa_name, bindiface))
&&
(bindll && is_linklocal((struct sockaddr_in6*)a->ifa_addr) ||
!bindll && (pass==2 || pass==0 && is_private6((struct sockaddr_in6*)a->ifa_addr) || pass==1 && !is_linklocal((struct sockaddr_in6*)a->ifa_addr)))
)
{
salisten->ss_family = AF_INET6;
memcpy(&((struct sockaddr_in6*)salisten)->sin6_addr, &((struct sockaddr_in6*)a->ifa_addr)->sin6_addr, sizeof(struct in6_addr));
if (if_index) *if_index = if_nametoindex(a->ifa_name);
found=true;
goto ex;
}
}
a = a->ifa_next;
}
}
ex:
freeifaddrs(addrs);
return found;
}
static bool read_system_maxfiles(rlim_t *maxfile)
{
#ifdef __linux__
FILE *F;
int n;
uintmax_t um;
if (!(F=fopen("/proc/sys/fs/file-max","r")))
return false;
n=fscanf(F,"%ju",&um);
fclose(F);
if (!n) return false;
*maxfile = (rlim_t)um;
return true;
#elif defined(BSD)
int maxfiles,mib[2]={CTL_KERN, KERN_MAXFILES};
size_t len = sizeof(maxfiles);
if (sysctl(mib,2,&maxfiles,&len,NULL,0)==-1)
return false;
*maxfile = (rlim_t)maxfiles;
return true;
#else
return false;
#endif
}
static bool write_system_maxfiles(rlim_t maxfile)
{
#ifdef __linux__
FILE *F;
int n;
if (!(F=fopen("/proc/sys/fs/file-max","w")))
return false;
n=fprintf(F,"%ju",(uintmax_t)maxfile);
fclose(F);
return !!n;
#elif defined(BSD)
int maxfiles=(int)maxfile,mib[2]={CTL_KERN, KERN_MAXFILES};
if (sysctl(mib,2,NULL,0,&maxfiles,sizeof(maxfiles))==-1)
return false;
return true;
#else
return false;
#endif
}
static bool set_ulimit()
{
rlim_t fdmax,fdmin_system,cur_lim=0;
int n;
if (!params.maxfiles)
{
// 4 fds per tamper connection (2 pipe + 2 socket), 6 fds for tcp proxy connection (4 pipe + 2 socket)
// additional 1/2 for unpaired remote legs sending buffers
// 16 for listen_fd, epoll, hostlist, ...
#ifdef SPLICE_PRESENT
fdmax = (params.tamper ? 4 : 6) * params.maxconn;
#else
fdmax = 2 * params.maxconn;
#endif
fdmax += fdmax/2 + 16;
}
else
fdmax = params.maxfiles;
fdmin_system = fdmax + 4096;
DBGPRINT("set_ulimit : fdmax=%ju fdmin_system=%ju",(uintmax_t)fdmax,(uintmax_t)fdmin_system)
if (!read_system_maxfiles(&cur_lim))
return false;
DBGPRINT("set_ulimit : current system file-max=%ju",(uintmax_t)cur_lim)
if (cur_lim<fdmin_system)
{
DBGPRINT("set_ulimit : system fd limit is too low. trying to increase to %jd",(uintmax_t)fdmin_system)
if (!write_system_maxfiles(fdmin_system))
{
fprintf(stderr,"could not set system-wide max file descriptors\n");
return false;
}
}
struct rlimit rlim = {fdmax,fdmax};
n=setrlimit(RLIMIT_NOFILE, &rlim);
if (n==-1) perror("setrlimit");
return n!=-1;
}
struct salisten_s
{
struct sockaddr_storage salisten;
socklen_t salisten_len;
int ipv6_only;
int bind_wait_ip_left; // how much seconds left from bind_wait_ip
};
int main(int argc, char *argv[])
{
int i, listen_fd[MAX_BINDS], yes = 1, retval = 0, if_index, exit_v=EXIT_FAILURE;
struct salisten_s list[MAX_BINDS];
char ip_port[48];
srand(time(NULL));
parse_params(argc, argv);
if (params.daemon) daemonize();
if (*params.pidfile && !writepid(params.pidfile))
{
fprintf(stderr,"could not write pidfile\n");
goto exiterr;
}
memset(&list, 0, sizeof(list));
for(i=0;i<=params.binds_last;i++) listen_fd[i]=-1;
for(i=0;i<=params.binds_last;i++)
{
VPRINT("Prepare bind %d : addr=%s iface=%s v6=%u link_local=%u link_local_force=%u wait_ifup=%d wait_ip=%d wait_ip_ll=%d",i,
params.binds[i].bindaddr,params.binds[i].bindiface,params.binds[i].bind_if6,params.binds[i].bindll,params.binds[i].bindll_force,
params.binds[i].bind_wait_ifup,params.binds[i].bind_wait_ip,params.binds[i].bind_wait_ip_ll);
if_index=0;
if (*params.binds[i].bindiface)
{
if (params.binds[i].bind_wait_ifup > 0)
{
int sec=0;
if (!is_interface_online(params.binds[i].bindiface))
{
printf("waiting for ifup of %s for up to %d second(s)...\n",params.binds[i].bindiface,params.binds[i].bind_wait_ifup);
do
{
sleep(1);
sec++;
}
while (!is_interface_online(params.binds[i].bindiface) && sec<params.binds[i].bind_wait_ifup);
if (sec>=params.binds[i].bind_wait_ifup)
{
printf("wait timed out\n");
goto exiterr;
}
}
}
if (!(if_index = if_nametoindex(params.binds[i].bindiface)) && params.binds[i].bind_wait_ip<=0)
{
printf("bad iface %s\n",params.binds[i].bindiface);
goto exiterr;
}
}
list[i].bind_wait_ip_left = params.binds[i].bind_wait_ip;
if (*params.binds[i].bindaddr)
{
if (inet_pton(AF_INET, params.binds[i].bindaddr, &((struct sockaddr_in*)(&list[i].salisten))->sin_addr))
{
list[i].salisten.ss_family = AF_INET;
}
else if (inet_pton(AF_INET6, params.binds[i].bindaddr, &((struct sockaddr_in6*)(&list[i].salisten))->sin6_addr))
{
list[i].salisten.ss_family = AF_INET6;
list[i].ipv6_only = 1;
}
else
{
printf("bad bind addr : %s\n", params.binds[i].bindaddr);
goto exiterr;
}
}
else
{
if (*params.binds[i].bindiface || params.binds[i].bindll)
{
bool found;
int sec=0;
if (params.binds[i].bind_wait_ip > 0)
{
printf("waiting for ip on %s for up to %d second(s)...\n", *params.binds[i].bindiface ? params.binds[i].bindiface : "<any>", params.binds[i].bind_wait_ip);
if (params.binds[i].bindll && !params.binds[i].bindll_force && params.binds[i].bind_wait_ip_ll>0)
printf("during the first %d second(s) accepting only link locals...\n", params.binds[i].bind_wait_ip_ll);
}
for(;;)
{
found = find_listen_addr(&list[i].salisten,params.binds[i].bindiface,params.binds[i].bind_if6,params.binds[i].bindll,&if_index);
if (found) break;
if (params.binds[i].bindll && !params.binds[i].bindll_force && sec>=params.binds[i].bind_wait_ip_ll)
if ((found = find_listen_addr(&list[i].salisten,params.binds[i].bindiface,params.binds[i].bind_if6,false,&if_index)))
{
printf("link local address wait timeout. using global address\n");
break;
}
if (sec>=params.binds[i].bind_wait_ip)
break;
sleep(1);
sec++;
}
if (!found)
{
printf("suitable ip address not found\n");
goto exiterr;
}
list[i].bind_wait_ip_left = params.binds[i].bind_wait_ip - sec;
list[i].ipv6_only=1;
}
else
{
list[i].salisten.ss_family = AF_INET6;
// leave sin6_addr zero
}
}
if (list[i].salisten.ss_family == AF_INET6)
{
list[i].salisten_len = sizeof(struct sockaddr_in6);
((struct sockaddr_in6*)(&list[i].salisten))->sin6_port = htons(params.port);
if (is_linklocal((struct sockaddr_in6*)(&list[i].salisten)))
((struct sockaddr_in6*)(&list[i].salisten))->sin6_scope_id = if_index;
}
else
{
list[i].salisten_len = sizeof(struct sockaddr_in);
((struct sockaddr_in*)(&list[i].salisten))->sin_port = htons(params.port);
}
}
if (params.bind_wait_only)
{
printf("bind wait condition satisfied\n");
exit_v = 0;
goto exiterr;
}
if (params.proxy_type==CONN_TYPE_TRANSPARENT && !redir_init())
{
fprintf(stderr,"could not initialize redirector !!!\n");
goto exiterr;
}
for(i=0;i<=params.binds_last;i++)
{
if (params.debug)
{
ntop46_port((struct sockaddr *)&list[i].salisten, ip_port, sizeof(ip_port));
VPRINT("Binding %d to %s",i,ip_port);
}
if ((listen_fd[i] = socket(list[i].salisten.ss_family, SOCK_STREAM, 0)) == -1) {
perror("socket");
goto exiterr;
}
#ifndef __OpenBSD__
// in OpenBSD always IPV6_ONLY for wildcard sockets
if ((list[i].salisten.ss_family == AF_INET6) && setsockopt(listen_fd[i], IPPROTO_IPV6, IPV6_V6ONLY, &list[i].ipv6_only, sizeof(int)) == -1)
{
perror("setsockopt (IPV6_ONLY)");
goto exiterr;
}
#endif
if (setsockopt(listen_fd[i], SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1)
{
perror("setsockopt (SO_REUSEADDR)");
goto exiterr;
}
//Mark that this socket can be used for transparent proxying
//This allows the socket to accept connections for non-local IPs
if (params.proxy_type==CONN_TYPE_TRANSPARENT)
{
#ifdef __linux__
if (setsockopt(listen_fd[i], SOL_IP, IP_TRANSPARENT, &yes, sizeof(yes)) == -1)
{
perror("setsockopt (IP_TRANSPARENT)");
goto exiterr;
}
#elif defined(BSD) && defined(SO_BINDANY)
if (setsockopt(listen_fd[i], SOL_SOCKET, SO_BINDANY, &yes, sizeof(yes)) == -1)
{
perror("setsockopt (SO_BINDANY)");
goto exiterr;
}
#endif
}
if (!set_socket_buffers(listen_fd[i], params.local_rcvbuf, params.local_sndbuf))
goto exiterr;
if (!params.local_rcvbuf)
{
// HACK : dont know why but if dont set RCVBUF explicitly RCVBUF of accept()-ed socket can be very large. may be linux bug ?
int v;
socklen_t sz=sizeof(int);
if (!getsockopt(listen_fd[i],SOL_SOCKET,SO_RCVBUF,&v,&sz))
{
v/=2;
setsockopt(listen_fd[i],SOL_SOCKET,SO_RCVBUF,&v,sizeof(int));
}
}
bool bBindBug=false;
for(;;)
{
if (bind(listen_fd[i], (struct sockaddr *)&list[i].salisten, list[i].salisten_len) == -1)
{
// in linux strange behaviour was observed
// just after ifup and address assignment there's short window when bind() can't bind to addresses got from getifaddrs()
// it does not happen to transparent sockets because they cant bind to any non-existend ip
// also only ipv6 seem to be buggy this way
if (errno==EADDRNOTAVAIL && params.proxy_type!=CONN_TYPE_TRANSPARENT && list[i].bind_wait_ip_left)
{
if (!bBindBug)
{
ntop46_port((struct sockaddr *)&list[i].salisten, ip_port, sizeof(ip_port));
printf("address %s is not available. will retry for %d sec\n",ip_port,list[i].bind_wait_ip_left);
bBindBug=true;
}
sleep(1);
list[i].bind_wait_ip_left--;
continue;
}
perror("bind");
goto exiterr;
}
break;
}
if (listen(listen_fd[i], BACKLOG) == -1)
{
perror("listen");
goto exiterr;
}
}
set_ulimit();
if (params.droproot && !droproot(params.uid,params.gid))
goto exiterr;
print_id();
//splice() causes the process to receive the SIGPIPE-signal if one part (for
//example a socket) is closed during splice(). I would rather have splice()
//fail and return -1, so blocking SIGPIPE.
if (block_sigpipe() == -1) {
fprintf(stderr, "Could not block SIGPIPE signal\n");
goto exiterr;
}
printf(params.proxy_type==CONN_TYPE_SOCKS ? "socks mode\n" : "transparent proxy mode\n");
if (!params.tamper) printf("TCP proxy mode (no tampering)\n");
signal(SIGHUP, onhup);
retval = event_loop(listen_fd,params.binds_last+1);
exit_v = retval < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
printf("Exiting\n");
exiterr:
redir_close();
for(i=0;i<=params.binds_last;i++) if (listen_fd[i]!=-1) close(listen_fd[i]);
cleanup_params();
return exit_v;
}