diff --git a/src/core.h b/src/core.h index 564df20..a9ad88b 100644 --- a/src/core.h +++ b/src/core.h @@ -25,6 +25,7 @@ #define __CORE_HEADER #define BUFF_SIZE 8*1024 // used to read responses from proxies. #define MAX_LOCALNET 64 +#define MAX_DNAT 64 #include "ip_type.h" @@ -68,6 +69,11 @@ typedef struct { unsigned short port; } localaddr_arg; +typedef struct { + struct in_addr orig_dst, new_dst; + unsigned short orig_port, new_port; +} dnat_arg; + typedef struct { ip_type ip; unsigned short port; diff --git a/src/libproxychains.c b/src/libproxychains.c index 8446bb0..6f91bd6 100644 --- a/src/libproxychains.c +++ b/src/libproxychains.c @@ -72,6 +72,8 @@ int proxychains_quiet_mode = 0; int proxychains_resolver = 0; localaddr_arg localnet_addr[MAX_LOCALNET]; size_t num_localnet_addr = 0; +dnat_arg dnats[MAX_DNAT]; +size_t num_dnats = 0; unsigned int remote_dns_subnet = 224; pthread_once_t init_once = PTHREAD_ONCE_INIT; @@ -268,6 +270,8 @@ static void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_typ char *env; char local_in_addr_port[32]; char local_in_addr[32], local_in_port[32], local_netmask[32]; + char dnat_orig_addr_port[32], dnat_new_addr_port[32]; + char dnat_orig_addr[32], dnat_orig_port[32], dnat_new_addr[32], dnat_new_port[32]; FILE *file = NULL; if(proxychains_got_chain_data) @@ -419,6 +423,55 @@ inv_host: proxychains_quiet_mode = 1; } else if(strstr(buff, "proxy_dns")) { proxychains_resolver = 1; + } else if(strstr(buff, "dnat")) { + if(sscanf(buff, "%s %21[^ ] %21s\n", user, dnat_orig_addr_port, dnat_new_addr_port) < 3) { + fprintf(stderr, "dnat format error"); + exit(1); + } + /* clean previously used buffer */ + memset(dnat_orig_port, 0, sizeof(dnat_orig_port) / sizeof(dnat_orig_port[0])); + memset(dnat_new_port, 0, sizeof(dnat_new_port) / sizeof(dnat_new_port[0])); + + (void)sscanf(dnat_orig_addr_port, "%15[^:]:%5s", dnat_orig_addr, dnat_orig_port); + (void)sscanf(dnat_new_addr_port, "%15[^:]:%5s", dnat_new_addr, dnat_new_port); + + if(num_dnats < MAX_DNAT) { + int error; + error = + inet_pton(AF_INET, dnat_orig_addr, + &dnats[num_dnats].orig_dst); + if(error <= 0) { + fprintf(stderr, "dnat original destination address error\n"); + exit(1); + } + + error = + inet_pton(AF_INET, dnat_new_addr, + &dnats[num_dnats].new_dst); + if(error <= 0) { + fprintf(stderr, "dnat effective destination address error\n"); + exit(1); + } + + if(dnat_orig_port[0]) { + dnats[num_dnats].orig_port = + (short) atoi(dnat_orig_port); + } else { + dnats[num_dnats].orig_port = 0; + } + + if(dnat_new_port[0]) { + dnats[num_dnats].new_port = + (short) atoi(dnat_new_port); + } else { + dnats[num_dnats].new_port = 0; + } + + PDEBUG("added dnat: orig-dst=%s orig-port=%d new-dst=%s new-port=%d\n", dnat_orig_addr, dnats[num_dnats].orig_port, dnat_new_addr, dnats[num_dnats].new_port); + ++num_dnats; + } else { + fprintf(stderr, "# of dnat exceed %d.\n", MAX_DNAT); + } } } } @@ -501,6 +554,24 @@ int connect(int sock, const struct sockaddr *addr, unsigned int len) { // check if connect called from proxydns remote_dns_connect = !v6 && (ntohl(p_addr_in->s_addr) >> 24 == remote_dns_subnet); + if (!v6) for(i = 0; i < num_dnats && !remote_dns_connect; i++) { + if(dnats[i].orig_dst.s_addr == p_addr_in->s_addr) { + if(!dnats[i].orig_port) { + p_addr_in = &dnats[i].new_dst; + if(dnats[i].new_port) + port = dnats[i].new_port; + + break; + } + else if(dnats[i].orig_port == port) { + p_addr_in = &dnats[i].new_dst; + if (dnats[i].new_port) + port = dnats[i].new_port; + break; + } + } + } + if (!v6) for(i = 0; i < num_localnet_addr && !remote_dns_connect; i++) { if((localnet_addr[i].in_addr.s_addr & localnet_addr[i].netmask.s_addr) == (p_addr_in->s_addr & localnet_addr[i].netmask.s_addr)) { diff --git a/src/proxychains.conf b/src/proxychains.conf index 83f7d90..65c04ad 100644 --- a/src/proxychains.conf +++ b/src/proxychains.conf @@ -90,6 +90,22 @@ tcp_connect_time_out 8000 # localnet 172.16.0.0/255.240.0.0 # localnet 192.168.0.0/255.255.0.0 +### Examples for dnat +## Trying to proxy connections to destinations which are dnatted, +## will result in proxying connections to the new given destinations. +## Whenever I connect to 1.1.1.1 on port 1234 actually connect to 1.1.1.2 on port 443 +# dnat 1.1.1.1:1234 1.1.1.2:443 + +## Whenever I connect to 1.1.1.1 on port 443 actually connect to 1.1.1.2 on port 443 +## (no need to write :443 again) +# dnat 1.1.1.2:443 1.1.1.2 + +## No matter what port I connect to on 1.1.1.1 port actually connect to 1.1.1.2 on port 443 +# dnat 1.1.1.1 1.1.1.2:443 + +## Always, instead of connecting to 1.1.1.1, connect to 1.1.1.2 +# dnat 1.1.1.1 1.1.1.2 + # ProxyList format # type ip port [user pass] # (values separated by 'tab' or 'blank')