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dnsp.c
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/*
* Copyright (c) 2013-2018 Massimiliano Fantuzzi HB3YOE <[email protected]>
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
//#define _GNU_SOURCE
#include <sys/wait.h>
#include <sys/utsname.h>
#include <sched.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/timeb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <errno.h>
//#include <spawn.h>
#include <stdarg.h>
#include <netdb.h>
#include <unistd.h>
#include <ctype.h>
#include <curl/curl.h>
#include <curl/easy.h>
#include <signal.h>
#include <semaphore.h>
#include <pthread.h>
//#include <omp.h>
#ifndef SIGCLD
# define SIGCLD SIGCHLD
#endif
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); } while (0)
#define handle_error(msg) do { perror(msg); exit(EXIT_FAILURE); } while (0)
#define VERSION "1.5"
/* Stack size for cloned child */
#define STACK_SIZE (1024 * 1024)
/* DELAY for CURL to wait ? do not remember, needs documentation */
#define DELAY 0
/* how can it be influenced, this CURL parameter ? kept for historical reasons, will not be useful in threaded model */
#define MAXCONN 4
#define UDP_DATAGRAM_SIZE 256
#define DNSREWRITE 256
#define HTTP_RESPONSE_SIZE 4096
#define URL_SIZE 256
#define DNS_MODE_ANSWER 0
#define DNS_MODE_ERROR 1
#define DEFAULT_LOCAL_PORT 53
#define DEFAULT_WEB_PORT 80
#define DEFAULT_PRX_PORT 1080
/* for threaded model, experimental options, not in use at the moment */
#define NUMT 2
#define NUM_THREADS 2
#define NUM_HANDLER_THREADS 1
//#define LOC_PREEMPT_DLD 1
//#define TYPEQ 2
//#define DEBUG 0
pthread_key_t glob_var_key_ip;
pthread_key_t glob_var_key_client;
//static pthread_mutex_t mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
//pthread_mutex_t mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
pthread_mutexattr_t MAttr;
#ifdef TLS
__thread int i;
#else
pthread_key_t key_i;
#endif
pthread_t *tid;
struct readThreadParams {
size_t xrequestlen;
char* xproxy_user;
char* xproxy_pass;
char* xproxy_host;
int xproxy_port;
char* xlookup_script;
char* xtypeq;
int xwport;
int sockfd;
int xsockfd;
//int digit;
//char* input;
struct dns_request *xhostname;
struct sockaddr_in *xclient;
struct sockaddr_in *yclient;
struct dns_request *xdns_req;
struct dns_request *dns_req;
};
struct thread_info { /* Used as argument to thread_start() */
pthread_t thread_id; /* ID returned by pthread_create() */
int thread_num; /* Application-defined thread # */
char *argv_string; /* From command-line argument */
};
/*
void start_thread(pthread_t *mt)
{
mystruct *data = malloc(sizeof(*data));
...;
pthread_create(mt, NULL, do_work_son, data);
}
*/
/*
void start_thread(pthread_t *mt)
{
//mystruct local_data = {};
//mystruct *data = malloc(sizeof(*data));
struct readThreadParams local_data = {};
struct readThreadParams *data = malloc(sizeof(*data));
*data = local_data;
//pthread_create(mt, NULL, threadFunc,readParams);
pthread_create(mt, NULL, thread_start,data);
//pthread_create(mt, NULL, threadFunc,data);
//ret = pthread_create(&pth[i],NULL,threadFunc,readParams);
//pthread_create(&pth[i],NULL,threadFunc,readParams);
}
*/
static void *
thread_start(void *arg)
{
struct thread_info *tinfo = arg;
char *uargv, *p;
printf("Thread %d: top of stack near %p; argv_string=%s\n",
tinfo->thread_num, &p, tinfo->argv_string);
uargv = strdup(tinfo->argv_string);
if (uargv == NULL)
handle_error("strdup");
for (p = uargv; *p != '\0'; p++)
*p = toupper(*p);
return uargv;
}
//struct thread_data{
// int threads;
// int thread_id;
// int exec; //total number of executions
// int max_req_client;
// int random; //1=yes 0=no whether requests are the max or randomdouble
// int ssl; //1=yes 0=no
// int uselogin; //1=yes 0=no
// char domain[256];
// char login[256];
// char password[256];
//};
int DEBUG, DEBUGCURL, LOC_PREEMPT_DLD;
char* substring(char*, int, int);
struct dns_request
{
uint16_t transaction_id,
questions_num,
flags,
qtype,
qclass;
char hostname[256],
query[256];
size_t hostname_len;
};
struct dns_reponse
{
size_t lenght;
char *payload;
};
/* usage */
void usage(void)
{
fprintf(stderr, "\n dnsp %s, copyright @ 2018 Massimiliano Fantuzzi, HB3YOE, MIT License\n\n"
" usage: dnsp [-l [local_host]] [-p [local_port:53,5353,..]] [-H [proxy_host]] [-r [proxy_port:8118,8888,3128,9500..]] \n"
"\t\t [-w [lookup_port:80,443,..]] [-s [lookup_script]]\n\n"
" OPTIONS:\n"
" -l\t\t Local server address (optional)\n"
" -p\t\t Local server port (optional, defaults to 53)\n"
" -H\t\t Cache proxy address (strongly suggested)\n"
" -r\t\t Cache proxy port (strongly suggested)\n"
" -u\t\t Cache proxy username (optional)\n"
" -k\t\t Cache proxy password (optional)\n"
" -s\t\t Lookup script URL (mandatory option)\n"
" -w\t\t Lookup port (obsolete, defaults to 80/443 for HTTP/HTTPS)\n"
" -t\t\t Stack size in format 0x1000000 (MB)\n"
"\n"
" TESTING/DEV OPTIONS:\n"
" -v\t\t Enable DEBUG\n"
" -C\t\t Enable CURL VERBOSE, useful to spot cache issues or dig down into HSTS/HTTPS quirks\n"
" -I\t\t Upgrade Insecure Requests, HSTS work in progress\n"
" -R\t\t Enable CURL resolve mechanism, avoiding extra gethostbyname, work in progress\n"
"\n"
" Example HTTPS direct : dnsp -s https://php-dns.appspot.com/\n"
" Example HTTP direct : dnsp -s http://www.fantuz.net/nslookup.php\n"
" Example HTTP w/cache : dnsp -r 8118 -H http://myproxy.example.com/ -s http://www.fantuz.net/nslookup.php\n\n"
,VERSION);
exit(EXIT_FAILURE);
}
/* Prints an error message and exit */
void error(const char *msg)
{
fprintf(stderr," *** %s: %s\n", msg, strerror(errno));
exit(EXIT_FAILURE);
}
/* Prints debug messages */
void debug_msg(const char* fmt, ...)
{
va_list ap;
if (DEBUG) {
fprintf(stdout, " [%d]> ", getpid());
va_start(ap, fmt);
vfprintf(stdout, fmt, ap);
va_end(ap);
}
}
/* Return the length of the pointed buffer */
size_t memlen(const char *buff)
{
size_t len = 0;
while (1) {
if (buff[len] == 0) break;
len ++;
}
return len;
}
/* Parses the dns request and returns the pointer to dns_request struct. Returns NULL on errors */
struct dns_request *parse_dns_request(const char *udp_request, size_t request_len)
{
struct dns_request *dns_req;
dns_req = malloc(sizeof(struct dns_request));
/* Transaction ID */
dns_req->transaction_id = (uint8_t)udp_request[1] + (uint16_t)(udp_request[0] << 8);
udp_request+=2;
/* Flags */
dns_req->flags = (uint8_t)udp_request[1] + (uint16_t)(udp_request[0] << 8);
udp_request+=2;
/* Questions num */
dns_req->questions_num = (uint8_t)udp_request[1] + (uint16_t)(udp_request[0] << 8);
udp_request+=2;
/* WHERE IS EDNS ?? */
/* Skipping 6 not interesting bytes, override with shortened answers (one of the initial purpose of DNSP software) */
/*
uint16_t Answers number
uint16_t Records number
uint16_t Additionals records number
*/
udp_request+=6;
/* Getting the dns query */
bzero(dns_req->query, sizeof(dns_req->query));
memcpy(dns_req->query, udp_request, sizeof(dns_req->query)-1);
/* Hostname */
bzero(dns_req->hostname, sizeof(dns_req->hostname));
dns_req->hostname_len = 0;
while (1) {
uint8_t len = udp_request[0]; /* Length of the next label */
if (len == 0) {
udp_request++;
break;
}
udp_request++;
if (dns_req->hostname_len + len >= sizeof(dns_req->hostname)) {
free(dns_req);
printf("CORE: size issue !!\n");
return NULL;
}
strncat(dns_req->hostname, udp_request, len); /* Append the current label to dns_req->hostname */
strncat(dns_req->hostname, ".", 1); /* Append a '.' */
dns_req->hostname_len+=len+1;
udp_request+=len;
}
/* Qtype */
dns_req->qtype = (uint8_t)udp_request[1] + (uint16_t)(udp_request[0] << 8);
udp_request+=2;
/* Qclass */
dns_req->qclass = (uint8_t)udp_request[1] + (uint16_t)(udp_request[0] << 8);
udp_request+=2;
return dns_req;
}
/* * Builds and sends the dns response datagram */
void build_dns_response(int sd, struct sockaddr_in *yclient, struct dns_request *dns_req, const char *ip, int mode, size_t xrequestlen)
{
char *rip = malloc(256 * sizeof(char));
//struct dns_request *dns_req;
//struct sockaddr_in *client;
//char *str, *arg;
//struct readThreadParams *params = malloc(sizeof(struct readThreadParams));
//struct readThreadParams *params = (struct readThreadParams*)arg;
//str=(char*)arg;
int sockfd; // = params->xsockfd;
int xsockfd; // = params->xsockfd;
//struct dns_request *xhostname = (struct dns_request *)xhostname->hostname;
char *response,
*qhostname, // = dns_req->hostname,
*token,
*pch,
*maxim,
*response_ptr;
//*ppch,
//*typeq,
//uint i,ppch;
int i,ppch;
ssize_t bytes_sent;
if (DEBUG) {
/*
printf("BUILD-xhostname-int : %u\n", (uint32_t)strlen(xhostname));
printf("BUILD-req-query : %s\n", dns_req->query);
*/
printf("BUILD-yclient->sin_addr.s_addr : %u\n", (uint32_t)(yclient->sin_addr).s_addr);
printf("BUILD-yclient->sin_port : %u\n", (uint32_t)(yclient->sin_port));
printf("BUILD-yclient->sin_family : %d\n", (uint32_t)(yclient->sin_family));
printf("BUILD-xrequestlen : %d\n", (uint32_t)(xrequestlen));
printf("BUILD-xsockfd : %u\n", xsockfd);
printf("BUILD-sockfd : %d\n", sockfd);
printf("BUILD-hostname : %s\n", dns_req->hostname);
/*
printf("BUILD-client->sa_family : %u\n", (struct sockaddr)&xclient->sa_family);
printf("BUILD-client->sa_data : %u\n", (uint32_t)client->sa_data);
printf("BUILD-hostname : %s\n", qhostname);
printf("build-qry = %s\n",(xdns_req->query));
printf("build-host %s\n",(char *)(xdns_req->hostname));
printf("build-answer %s\n", rip);
printf("build-answer-mode %d\n", DNS_MODE_ANSWER);
*/
printf("\n");
}
response = malloc (UDP_DATAGRAM_SIZE);
bzero(response, UDP_DATAGRAM_SIZE);
maxim = malloc (DNSREWRITE);
bzero(maxim, DNSREWRITE);
//maxim_ptr = maxim;
response_ptr = response;
/* Transaction ID */
response[0] = (uint8_t)(dns_req->transaction_id >> 8);
response[1] = (uint8_t)dns_req->transaction_id;
response+=2;
/*
TXT, SRV, SOA, PTR, NS, MX, DS, DNSKEY, AAAA, A, unused
A IPv4 host address 0x0001
AAAA IPv6 host address 0x001c
NS authoritative name server 0x0002
CNAME alias canonical name 0x0005
SOA start of zone authority 0x0006
PTR Domain name pointer 0x000c
HINFO host info 0x000d
MINFO mailbox/mail list info 0x000e
MX mail exchange 0x000f
AXFR zone transfer 0x00fc
*/
if (mode == DNS_MODE_ANSWER) {
/* Default flags for a standard query (0x8580) */
/* Shall it be authoritative answer... or not ? :) */
//response[0] = 0x81;
response[0] = 0x85;
response[1] = 0x80;
response+=2;
/* Questions 1 */
response[0] = 0x00;
response[1] = 0x01;
response+=2;
/* Answers 1 */
response[0] = 0x00;
response[1] = 0x01;
response+=2;
} else if (mode == DNS_MODE_ERROR) {
/* DNS_MODE_ERROR should truncate message instead of building it up ... */
/* Server failure (0x8182), but what if we want NXDOMAIN (0x....) ???*/
/*
* NOERROR (RCODE:0) : DNS Query completed successfully
* FORMERR (RCODE:1) : DNS Query Format Error
* SERVFAIL (RCODE:2) : Server failed to complete the DNS request
* NXDOMAIN (RCODE:3) : Domain name does not exist
* NOTIMP (RCODE:4) : Function not implemented
* REFUSED (RCODE:5) : The server refused to answer for the query
* YXDOMAIN (RCODE:6) : Name that should not exist, does exist
* XRRSET (RCODE:7) : RRset that should not exist, does exist
* NOTAUTH (RCODE:9) : Server not authoritative for the zone
* NOTZONE (RCODE:10) : Name not in zone
* 11-15 available for assignment
* 16 BADVERS Bad OPT Version
* 16 BADSIG TSIG Signature Failure
* 17 BADKEY Key not recognized
* 18 BADTIME Signature out of time window
* 19 BADMODE Bad TKEY Mode
* 20 BADNAME Duplicate key name
* 21 BADALG Algorithm not supported
* 22-3840 available for assignment
* 0x0016-0x0F00
* 3841-4095 Private Use
* 0x0F01-0x0FFF
* 4096-65535 available for assignment
* 0x1000-0xFFFF
*/
response[0] = 0x81;
response[1] = 0x82;
response+=2;
/* Questions 1 */
response[0] = 0x00;
response[1] = 0x01;
response+=2;
/* Answers 0 */
response[0] = 0x00;
response[1] = 0x00;
response+=2;
/* Are we into "No such name" ?... just an NXDOMAIN ?? */
//*response++ = 0x00;
}
/* Authority RRs 0 */
response[0] = 0x00;
response[1] = 0x00;
response+=2;
/* Additional RRs 0 */
response[0] = 0x00;
response[1] = 0x00;
response+=2;
/* Query */
strncat(response, dns_req->query, dns_req->hostname_len);
response+=dns_req->hostname_len+1;
/* Type */
response[0] = (uint8_t)(dns_req->qtype >> 8);
response[1] = (uint8_t)dns_req->qtype;
response+=2;
/* Class */
response[0] = (uint8_t)(dns_req->qclass >> 8);
response[1] = (uint8_t)dns_req->qclass;
response+=2;
/* Answer */
if (mode == DNS_MODE_ANSWER) {
/* Pointer to host name in query section */
response[0] = 0xc0;
response[1] = 0x0c;
response+=2;
if (dns_req->qtype == 0x0f) {
// MX
response[0] = 0x00;
response[1] = 0x0f;
response+=2;
} else if (dns_req->qtype == 0xFF) {
// ALL
response[0] = 0x00;
response[1] = 0xFF;
response+=2;
} else if (dns_req->qtype == 0x01) {
// A
*response++ = 0x00;
*response++ = 0x01;
} else if (dns_req->qtype == 0x05) {
// CNAME
response[0] = 0x00;
response[1] = 0x05;
response+=2;
} else if (dns_req->qtype == 0x0c) {
// PTR
response[0] = 0x00;
response[1] = 0x0c;
response+=2;
} else if (dns_req->qtype == 0x02) {
// NS
response[0] = 0x00;
response[1] = 0x02;
response+=2;
} else {
//return;
}
/* Class IN */
*response++ = 0x00;
*response++ = 0x01;
/* TTL (4 hours) */
*response++ = 0x00;
*response++ = 0x00;
*response++ = 0x38;
*response++ = 0x40;
/*
* 0x08 - backspace \010 octal
* 0x09 - horizontal tab
* 0x0a - linefeed
* 0x0b - vertical tab \013 octal
* 0x0c - form feed
* 0x0d - carriage return
* 0x20 - space
*/
/* TYPES */
if (dns_req->qtype == 0x0c) {
// PTR
/* Data length (4 bytes)*/
response[0] = 0x00;
response[1] = 0x04;
response+=2;
response[0] = 0xc0;
response[1] = 0x0c;
response+=2;
} else if (dns_req->qtype == 0x02) {
// NS
response[0] = 0x00;
response[1] = (strlen(ip)-1);
response+=2;
pch = strtok((char *)ip,". \r\n\t");
while (pch != NULL)
{
ppch = strlen(pch);
*response++ = strlen(pch);
for (i = 0; i < strlen(pch); ++i) {
*response++ = pch[i];
maxim[i] = pch[i];
}
pch = strtok(NULL, ". ");
//if (pch != ' ' && pch != '\t' && pch != NULL) {
//if (pch == ' ' || pch == '\t' || pch == NULL || pch == '\n' || pch == '\r') {
if (pch == NULL) {
for (i = 0; i < ppch+1; ++i) {
response--;
}
*response++ = ppch-3;
for (i = 0; i < ppch-3; ++i) {
*response++ = maxim[i];
}
}
}
*response++ = 0x00;
} else if (dns_req->qtype == 0x05) {
// CNAME
response[0] = 0x00;
response[1] = (strlen(ip)-1);
response+=2;
pch = strtok((char *)ip,". \r\n\t");
while (pch != NULL)
{
ppch = strlen(pch);
*response++ = strlen(pch);
for (i = 0; i < strlen(pch); ++i) {
*response++ = pch[i];
maxim[i] = pch[i];
}
pch = strtok (NULL, ". ");
if (pch == NULL) {
for (i = 0; i < ppch+1; ++i) {
response--;
}
*response++ = ppch-3;
for (i = 0; i < ppch-3; ++i) {
*response++ = maxim[i];
}
}
}
*response++ = 0x00;
} else if (dns_req->qtype == 0x0f) {
//MX RECORD
/* Data length accounting for answer plus final dot and termination field */
response[0] = 0x00;
response[1] = (strlen(ip)+3);
response+=2;
/* PRIO (4 bytes)*/
response[0] = 0x00;
response[1] = 0x0a;
response+=2;
/* POINTER, IF YOU ARE SO BRAVE OR ABLE TO USE IT (4 bytes) -> do not use label-mode then...
* in that case, you should re-write the code to have super-duper minimal responses.
* That code would also need to implement domain comparison to check if suffix can be appended */
//response[0] = 0xc0;
//response[1] = 0x0c;
//response+=2;
pch = strtok((char *)ip,".\r\n\t");
while (pch != NULL)
{
//maxim = NULL;
ppch = strlen(pch);
*response++ = strlen(pch);
for (i = 0; i < strlen(pch); ++i) {
*response++ = pch[i];
//maxim[0] += 0x00;
maxim[i] = pch[i];
}
//strcat(response, pch);
//*response++ = *maxim;
pch = strtok (NULL, ".");
if (pch == NULL) {
for (i = 0; i < ppch+1; ++i) {
response--;
}
*response++ = ppch-1;
for (i = 0; i < ppch-1; ++i) {
*response++ = maxim[i];
}
}
}
*response++ = 0x00;
} else if (dns_req->qtype == 0x01) { // A RECORD
/* Data length (4 bytes)*/
*response++ = 0x00;
*response++ = 0x04;
token = strtok((char *)ip,".");
if (token != NULL) response[0] = atoi(token);
else return;
token = strtok(NULL,".");
if (token != NULL) response[1] = atoi(token);
else return;
token = strtok(NULL,".");
if (token != NULL) response[2] = atoi(token);
else return;
token = strtok(NULL,".");
if (token != NULL) response[3] = atoi(token);
else return;
response+=4;
} else {
fprintf(stdout, "DNS_MODE_ISSUE\n");
//return;
}
//*response++=(unsigned char)(strlen(ip)+1); //memcpy(response,ip,strlen(ip)-1); //strncpy(response,ip,strlen(ip)-1);
//recvfrom(3, "\326`\1 \0\1\0\0\0\0\0\1\6google\2it\0\0\1\0\1\0\0)\20\0"..., 256, 0, {sa_family=AF_INET, sin_port=htons(48379), sin_addr=inet_addr("192.168.2.84")}, [16]) = 38
//(3, "\24\0\0\0\26\0\1\3\23\306;U\0\0\0\0\0\0\0\0", 20, 0, {sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 20
//(3, "z\271\205\200\0\1\0\1\0\0\0\0\6google\2hr\0\0\2\0\1\300\f\0\2\0"..., 41, 0, {sa_family=0x1a70 /* AF_??? */, sa_data="s\334\376\177\0\0\20D\1\270\223\177\0\0"}, 8)
//(struct sockaddr *)xclient->sin_family = AF_INET;
int yclient_len = sizeof(yclient);
yclient->sin_family = AF_INET;
//yclient->sin_addr.s_addr = inet_addr("192.168.2.84");
//yclient->sin_port = htons(yclient->sin_port);
yclient->sin_port = yclient->sin_port;
memset(&(yclient->sin_zero), 0, sizeof(yclient->sin_zero)); // zero the rest of the struct
//memset(yclient, 0, 0);
if (DEBUG) {
printf("INSIDE-raw-datagram : %s\n", response);
printf("INSIDE-yclient->sin_addr.s_addr : %u\n", (uint32_t)(yclient->sin_addr).s_addr);
printf("INSIDE-yclient->sin_port : %u\n", (uint32_t)(yclient->sin_port));
printf("INSIDE-yclient->sin_port : %u\n", htons(yclient->sin_port));
printf("INSIDE-yclient->sin_family : %d\n", (uint32_t)(yclient->sin_family));
printf("INSIDE-dns-req->hostname : %s\n", dns_req->hostname);
printf("INSIDE-xrequestlen : %u\n", (uint16_t)xrequestlen);
/*
printf("INSIDE-dns_req->query : %s\n", dns_req->query);
printf("INSIDE-xdns_req->query : %s\n", xdns_req->query);
printf("INSIDE-xdns_req->hostname-to-char : %s\n", (char *)(xdns_req->hostname));
printf("INSIDE-xdns_req->hostname : %s\n", xdns_req->hostname);
printf("INSIDE-xdns_req->query : %s\n", xdns_req->query);
*/
printf("\n");
}
/* example kept for educational purposes, to show how the response packet is built, tailored for the client */
//bytes_sent = sendto(3, "\270\204\205\200\0\1\0\1\0\0\0\0\6google\2jp\0\0\1\0\1\300\f\0\1\0"..., 43, 0, {sa_family=0x0002 /* AF_??? */, sa_data="\365\366\374\177\0\0\1\0\0\0\3\0\0\0"}, 16)
//bytes_sent = sendto(sd, response_ptr, response - response_ptr, 0, (struct sockaddr *)(&yclient), sizeof(yclient));
bytes_sent = sendto(sd, response_ptr, response - response_ptr, 0, (struct sockaddr *)yclient, 16);
} else if (mode == DNS_MODE_ERROR) {
fprintf(stdout, "DNS_MODE_ERROR\n");
//(struct sockaddr *)xclient->sin_family = AF_INET;
int yclient_len = sizeof(yclient);
yclient->sin_family = AF_INET;
//yclient->sin_addr.s_addr = inet_addr("192.168.2.84");
//yclient->sin_port = htons(yclient->sin_port);
yclient->sin_port = yclient->sin_port;
memset(&(yclient->sin_zero), 0, sizeof(yclient->sin_zero)); // zero the rest of the struct
//memset(yclient, 0, 0);
bytes_sent = sendto(sd, response_ptr, response - response_ptr, 0, (struct sockaddr *)yclient, 16);
} else {
fprintf(stdout, "DNS_MODE_UNKNOWN\n");
bytes_sent = sendto(sd, response_ptr, response - response_ptr, 0, (struct sockaddr *)yclient, 16);
}
/* DNS PACKET/VOLUME DISPLAY */
if (DEBUG) {
printf("SENT %d bytes\n", (uint32_t)bytes_sent);
}
fdatasync(sd);
close(sd);
free(response_ptr);
free(dns_req);
//free(ip);
}
/* new */
struct MemoryStruct {
char *memory;
size_t size;
};
/* new libCurl callback */
static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
{
size_t realsize = size * nmemb;
struct MemoryStruct *mem = (struct MemoryStruct *)userp;
mem->memory = realloc(mem->memory, mem->size + realsize + 1);
if(mem->memory == NULL) {
/* out of memory! */
printf("not enough memory (realloc returned NULL)\n");
return 0;
}
memcpy(&(mem->memory[mem->size]), contents, realsize);
mem->size += realsize;
mem->memory[mem->size] = 0;
return realsize;
}
/* libCurl write data callback */
static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
{
size_t stream_size;
stream_size = size * nmemb + 1;
bzero(stream, HTTP_RESPONSE_SIZE);
memcpy(stream, ptr, stream_size);
//return 0;
return stream_size-1;
}
char *substring(char *string, int position, int length)
{
char *pointer;
int c;
pointer = malloc(length+1);
if (pointer == NULL)
{
printf("Unable to allocate memory.\n");
exit(1);
}
for (c = 0 ; c < length ; c++)
{
*(pointer+c) = *(string+position-1);
string++;
}
*(pointer+c) = '\0';
return pointer;
}
/* Hostname lookup -> OK: Resolved IP, KO: Null */
char *lookup_host(const char *host, const char *proxy_host, unsigned int proxy_port, const char *proxy_user, const char *proxy_pass, const char *lookup_script, const char *typeq, unsigned int wport)
{
CURL *ch;
CURLSH *curlsh;
//CURLcode res;
char *http_response,
*script_url,
*pointer;
//*proxy_url,
char base[2];
int ret;
//struct curl_slist *hosting = NULL;
struct curl_slist *list = NULL;
//struct MemoryStruct chunk;
//chunk.memory = malloc(1); /* will be grown as needed by the realloc above */
//chunk.size = 0; /* no data at this point */
script_url = malloc(URL_SIZE);
http_response = malloc(HTTP_RESPONSE_SIZE);
bzero(script_url, URL_SIZE);
snprintf(script_url, URL_SIZE-1, "%s?host=%s&type=%s", lookup_script, host, typeq);
//proxy_url = malloc(URL_SIZE);
//bzero(proxy_url, URL_SIZE);
//snprintf(proxy_url, URL_SIZE-1, "http://%s/", proxy_host);
/*
if (proxy_host != NULL) {
fprintf(stderr, "Required substring is \"%s\"\n", proxy_url);
}
*/
//printf(http_response);
/* HTTPS DETECTION CODE ... might be better :) */
pointer = substring(script_url, 5, 1);
strcpy(base, "s");
int result = strcmp(pointer, base);
//printf("Required substring is \"%s\"\n", pointer);
//printf("Compared substring is \"%s\"\n", base);
//printf("Result is \"%d\"\n", result);
if(result == 0) {
wport=443;
} else {
printf(" *** HTTP does NOT guarantee against MITM attacks. Consider switching to HTTPS webservice\n");
wport=80;
}
free(pointer);
/* curl setup */
ch = curl_easy_init();
/* to add soon */
/*
CURLOPT_MAXREDIRS, 2
CURLOPT_COOKIEJAR, "cookies.txt"
CURLOPT_COOKIEFILE, "cookies.txt"
CURLOPT_ENCODING, "gzip" check, is DEFLATE mostly
CURLOPT_TIMEOUT, 5 choosen 5 as value
CURLOPT_HEADER, 1
*/
curl_easy_setopt(ch, CURLOPT_URL, script_url);
curl_easy_setopt(ch, CURLOPT_PORT, wport); /* 80, 443 */
/* Proxy configuration section */
//curl_easy_setopt(ch, CURLOPT_PROXY, proxy_host);
//curl_easy_setopt(ch, CURLOPT_PROXY, "http://127.0.0.1/");
//curl_easy_setopt(ch, CURLOPT_PROXYPORT, 3128); /* 1080, 8118, 8888, 9500, ... */
curl_easy_setopt(ch, CURLOPT_PROXY, proxy_host);
curl_easy_setopt(ch, CURLOPT_PROXYPORT, proxy_port); /* 1080, 3128, 8118, 8888, 9500, ... */
curl_easy_setopt(ch, CURLOPT_PROXYTYPE, CURLPROXY_HTTP);
/* optional proxy username and password */
if ((proxy_user != NULL) && (proxy_pass != NULL)) {
curl_easy_setopt(ch, CURLOPT_PROXYUSERNAME, proxy_user);
curl_easy_setopt(ch, CURLOPT_PROXYPASSWORD, proxy_pass);
}
curl_easy_setopt(ch, CURLOPT_MAXCONNECTS, MAXCONN);
//curl_easy_setopt(ch, CURLOPT_FRESH_CONNECT, 0);
curl_easy_setopt(ch, CURLOPT_FRESH_CONNECT, 0);
curl_easy_setopt(ch, CURLOPT_FORBID_REUSE, 0);
//curl_setopt($curl, CURLOPT_AUTOREFERER, 1);
/* send all data to this function */
//curl_easy_setopt(ch, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
curl_easy_setopt(ch, CURLOPT_WRITEFUNCTION, write_data);
/* we pass our 'chunk' struct to the callback function */
//curl_easy_setopt(ch, CURLOPT_WRITEDATA, (void *)&chunk);
curl_easy_setopt(ch, CURLOPT_WRITEDATA, http_response);
/* cache with HTTP/1.1 304 Not Modified */
/* OPTION --> FOLLOW-LOCATION, necessary if getting HTTP 301 */
// HTTP/1.1 301 Moved Permanently
// Location: http://www.example.org/index.asp
curl_easy_setopt(ch, CURLOPT_FOLLOWLOCATION, 1);
//LOC_PREEMPT_DLD
// LOAD YOUR CA/CERT HERE
//static const char *pCertFile = "testcert.pem";
//static const char *pCACertFile="fantuznet.pem";
//static const char *pHeaderFile = "dumpit";
//curl_easy_setopt(ch, CURLOPT_CAINFO, pCACertFile);
curl_easy_setopt(ch, CURLOPT_SSL_VERIFYHOST, 2L);;
curl_easy_setopt(ch, CURLOPT_SSL_VERIFYPEER, 1L);
curl_easy_setopt(ch, CURLOPT_SSL_VERIFYSTATUS, 0L);
//curl_easy_setopt(ch, CURLOPT_SSLVERSION, CURL_SSLVERSION_DEFAULT); //CURL_SSLVERSION_TLSv1
curl_easy_setopt(ch, CURLOPT_TIMEOUT, 3);
curl_easy_setopt(ch, CURLOPT_DNS_CACHE_TIMEOUT, 3600);
curl_easy_setopt(ch, CURLOPT_DNS_USE_GLOBAL_CACHE, 1); /* DNS CACHE */
curl_easy_setopt(ch, CURLOPT_NOPROGRESS, 1L); /* No progress meter */
/* disable Nagle with 0, for bigger packets (full MSS) */
curl_easy_setopt(ch, CURLOPT_TCP_NODELAY, 1L);
if (DEBUGCURL) {
curl_easy_setopt(ch, CURLOPT_VERBOSE, 1); /* Verbose ON */
} else {
curl_easy_setopt(ch, CURLOPT_VERBOSE, 0); /* Verbose OFF */
}
/* test for HTTP */
//curl -s -H "Host: www.fantuz.net" -H "Remote Address:104.27.133.199:80" -H "User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36" 'http://www.fantuz.net/nslookup.php?host=fantuz.net&type=NS' | xxd
//curl -s -H "Host: php-dns.appspot.com" -H "User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36" 'http://php-dns.appspot.com/helloworld.php?host=fantuz.net&type=NS' | xxd
/* polipo likes pipelining, reuse, pretty powerful */
/* how about squid/nginx et al. ?? */
/* anyway all will change with H2 */
/* PROXY HOST INPUT VALIDATION ... to be improved for sanitisation */
/*
if (DEBUG) {
printf(" *** Fetching cache from HTTP proxy at http://%s:%d\n", proxy_host, proxy_port);
//printf(" *** Fetching cache from HTTP proxy at %s:%d\n", proxy_url);
}
*/
/* OVERRIDE RESOLVER --> add resolver CURL header, work in progress */
// in the form of CLI --resolve my.site.com:80:1.2.3.4, -H "Host: my.site.com"
/* OPTIONAL HEADERS, set with curl_slist_append */
//list = curl_slist_append(list, "Request URL: http://www.fantuz.net/nslookup.php");
//list = curl_slist_append(list, "Remote Address: 217.114.216.51:80");
//list = curl_slist_append(list, "User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36");