From ab2584d42d1a95fbe3d416433caf15d9abe2c727 Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Sun, 11 Jun 2006 12:57:29 +0000 Subject: [PATCH] beginning of combining dns and dnsd --- Makefile | 2 +- dns.c | 253 ++++++++++++++++++++++++++++++++++++++++++ dns.h | 12 ++ dnsd.c | 323 ------------------------------------------------------ dnsd.h | 33 ------ iodined.c | 1 - 6 files changed, 266 insertions(+), 358 deletions(-) delete mode 100644 dnsd.c delete mode 100644 dnsd.h diff --git a/Makefile b/Makefile index a374bc4..daf2d81 100644 --- a/Makefile +++ b/Makefile @@ -2,7 +2,7 @@ CC = gcc CLIENT = iodine CLIENTOBJS = iodine.o tun.o dns.o read.o SERVER = iodined -SERVEROBJS = iodined.o tun.o dnsd.o read.o +SERVEROBJS = iodined.o tun.o dns.o read.o OS = `uname | tr "a-z" "A-Z"` diff --git a/dns.c b/dns.c index aabac2b..0b64fa8 100644 --- a/dns.c +++ b/dns.c @@ -45,6 +45,15 @@ uint16_t chunkid; uint16_t pingid; +int outid; +int outbuflen; +char outbuf[64*1024]; +char delayed_q_name[256]; +short delayed_q_type; +short delayed_q_id; +struct sockaddr_in delayed_q_from; +int delayed_q_fromlen; + int open_dns(const char *host, const char *domain) { @@ -358,3 +367,247 @@ host2dns(const char *host, char *buffer, int size) return p - buffer; } + +int +dnsd_haspacket() +{ + return (outbuflen > 0); +} + +int +dnsd_hasack() +{ + return (delayed_q_id != 0); +} + +void +dnsd_queuepacket(const char *buf, const int buflen) +{ + memcpy(outbuf, buf, buflen); + + outbuflen = buflen; + outid++; +} + +static void +dnsd_send(int fd, char *name, short type, short id, struct sockaddr_in from) +{ + int len; + char *p; + char buf[64*1024]; + HEADER *header; + + memset(buf, 0, sizeof(buf)); + + len = 0; + header = (HEADER*)buf; + + header->id = htons(id); + header->qr = 1; + header->opcode = 0; + header->aa = 1; + header->tc = 0; + header->rd = 0; + header->ra = 0; + + header->qdcount = htons(1); + header->ancount = htons(1); + + p = buf + sizeof(HEADER); + + p += host2dns(name, p, strlen(name)); + PUTSHORT(type, p); + PUTSHORT(C_IN, p); + + p += host2dns(name, p, strlen(name)); + PUTSHORT(type, p); + PUTSHORT(C_IN, p); + PUTLONG(0, p); + + if(outbuflen > 0) { + PUTSHORT(outbuflen, p); + memcpy(p, outbuf, outbuflen); + p += outbuflen; + } else { + PUTSHORT(0, p); + } + + len = p - buf; +// printf("Responding with %d\n", len); + sendto(fd, buf, len, 0, (struct sockaddr*)&from, sizeof(from)); + + outbuflen = 0; +} + +void +dnsd_forceack(int fd) +{ + dnsd_send(fd, delayed_q_name, delayed_q_type, delayed_q_id, delayed_q_from); + delayed_q_id = 0; +} + +struct packet +{ + int len; + int offset; + char data[64*1024]; +}; + +static int +decodepacket(const char *name, struct packet *packet) +{ + int r; + int len; + int last; + int ping; + char *dp; + char *domain; + const char *np; + + len = 0; + last = (name[0] == '1'); + ping = (name[0] == 'p' || name[0] == 'P'); + + domain = strstr(name, topdomain); + + if (!ping && domain) { + np = name + 1; + dp = packet->data + packet->offset; + + while(np < domain) { + if(*np == '.') { + np++; + continue; + } + + sscanf(np, "%02X", &r); + *dp++ = (char)r; + np+=2; + len++; + } + + packet->len += len; + packet->offset += len; + } + + if(last) { + len = packet->len; + packet->len = packet->offset = 0; + } else { + len = 0; + } + + return len; +} + +int +open_dnsd(const char *domain) +{ + int fd; + int flag; + struct sockaddr_in addr; + + bzero(&addr, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(53); + addr.sin_addr.s_addr = htonl(INADDR_ANY); + + fd = socket(AF_INET, SOCK_DGRAM, 0); + if(fd < 0) { + warn("socket"); + return 0; + } + + flag = 1; +#ifdef SO_REUSEPORT + setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &flag, sizeof(flag)); +#endif + setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(flag)); + + if(bind(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) { + warn("bind"); + return 0; + } + + printf("Opened UDP socket\n"); + + // Save top domain used + strncpy(topdomain, domain, sizeof(topdomain) - 2); + topdomain[sizeof(topdomain) - 1] = 0; + + packetlen = 0; + delayed_q_type = 0; + delayed_q_id = 0; + delayed_q_fromlen = 0; + + return fd; +} + +void +close_dnsd(int fd) +{ + close(fd); +} + +struct packet packetbuf; + +int +dnsd_read(int fd, char *buf, int buflen) +{ + int r; + short id; + short type; + short class; + short qdcount; + char *data; + char name[255]; + HEADER *header; + socklen_t addrlen; + char packet[64*1024]; + struct sockaddr_in from; + + addrlen = sizeof(struct sockaddr); + r = recvfrom(fd, packet, sizeof(packet), 0, (struct sockaddr*)&from, &addrlen); + + //printf("Read %d bytes DNS query from %s\n", r, inet_ntoa(from.sin_addr)); + + if(r == -1) { + perror("recvfrom"); + } else { + header = (HEADER*)packet; + + id = ntohs(header->id); + + data = packet + sizeof(HEADER); + + if(!header->qr) { + qdcount = ntohs(header->qdcount); + + if(qdcount == 1) { + bzero(name, sizeof(name)); + READNAME(packet, name, data); + READSHORT(type, data); + READSHORT(class, data); + + if (dnsd_haspacket()) { + dnsd_send(fd, name, type, id, from); + } else { + // Store needed info about delayed response + strncpy(delayed_q_name, name, 256); + delayed_q_type = type; + delayed_q_id = id; + delayed_q_fromlen = addrlen; + memcpy((struct sockaddr*)&delayed_q_from, (struct sockaddr*)&from, addrlen); + } + + r = decodepacket(name, &packetbuf); + + memcpy(buf, packetbuf.data, r); + + return r; + } + } + } + + return 0; +} diff --git a/dns.h b/dns.h index 8fc447d..d332cfb 100644 --- a/dns.h +++ b/dns.h @@ -27,5 +27,17 @@ void dns_query(int, int, char *, int); int dns_write(int, int, char *, int, int); int dns_read(int, char *, int); +extern struct sockaddr_in peer; + +int open_dnsd(const char *); +void close_dnsd(int); + +int dnsd_read(int, char *, int); + +int dnsd_haspacket(); +int dnsd_hasack(); +void dnsd_forceack(int); +void dnsd_queuepacket(const char *, const int); + #endif /* _DNS_H_ */ diff --git a/dnsd.c b/dnsd.c deleted file mode 100644 index 179a17b..0000000 --- a/dnsd.c +++ /dev/null @@ -1,323 +0,0 @@ -/* - * Copyright (c) 2006 Bjorn Andersson , Erik Ekman - * - * Permission to use, copy, modify, and distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "dns.h" -#include "read.h" - -static int host2dns(const char *, char *, int); - -struct sockaddr_in peer; -char topdomain[256]; - -// Current IP packet -int packetlen; -char activepacket[4096]; - -int outid; -int outbuflen; -char outbuf[64*1024]; -char delayed_q_name[256]; -short delayed_q_type; -short delayed_q_id; -struct sockaddr_in delayed_q_from; -int delayed_q_fromlen; - -int -open_dnsd(const char *domain) -{ - int fd; - int flag; - struct sockaddr_in addr; - - bzero(&addr, sizeof(addr)); - addr.sin_family = AF_INET; - addr.sin_port = htons(53); - addr.sin_addr.s_addr = htonl(INADDR_ANY); - - fd = socket(AF_INET, SOCK_DGRAM, 0); - if(fd < 0) { - warn("socket"); - return 0; - } - - flag = 1; -#ifdef SO_REUSEPORT - setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &flag, sizeof(flag)); -#endif - setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(flag)); - - if(bind(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) { - warn("bind"); - return 0; - } - - printf("Opened UDP socket\n"); - - // Save top domain used - strncpy(topdomain, domain, sizeof(topdomain) - 2); - topdomain[sizeof(topdomain) - 1] = 0; - - packetlen = 0; - delayed_q_type = 0; - delayed_q_id = 0; - delayed_q_fromlen = 0; - - return fd; -} - -void -close_dnsd(int fd) -{ - close(fd); -} - -static int -host2dns(const char *host, char *buffer, int size) -{ - char *h; - char *p; - char *word; - - h = strdup(host); - memset(buffer, 0, size); - p = buffer; - - word = strtok(h, "."); - while(word) { - *p++ = (char)strlen(word); - memcpy(p, word, strlen(word)); - p += strlen(word); - - word = strtok(NULL, "."); - } - - *p++ = 0; - - free(h); - - return p - buffer; -} - -int -dnsd_haspacket() -{ - return (outbuflen > 0); -} - -int -dnsd_hasack() -{ - return (delayed_q_id != 0); -} - -void -dnsd_queuepacket(const char *buf, const int buflen) -{ - memcpy(outbuf, buf, buflen); - - outbuflen = buflen; - outid++; -} - -static void -dnsd_send(int fd, char *name, short type, short id, struct sockaddr_in from) -{ - int len; - char *p; - char buf[64*1024]; - HEADER *header; - - memset(buf, 0, sizeof(buf)); - - len = 0; - header = (HEADER*)buf; - - header->id = htons(id); - header->qr = 1; - header->opcode = 0; - header->aa = 1; - header->tc = 0; - header->rd = 0; - header->ra = 0; - - header->qdcount = htons(1); - header->ancount = htons(1); - - p = buf + sizeof(HEADER); - - p += host2dns(name, p, strlen(name)); - PUTSHORT(type, p); - PUTSHORT(C_IN, p); - - p += host2dns(name, p, strlen(name)); - PUTSHORT(type, p); - PUTSHORT(C_IN, p); - PUTLONG(0, p); - - if(outbuflen > 0) { - PUTSHORT(outbuflen, p); - memcpy(p, outbuf, outbuflen); - p += outbuflen; - } else { - PUTSHORT(0, p); - } - - len = p - buf; -// printf("Responding with %d\n", len); - sendto(fd, buf, len, 0, (struct sockaddr*)&from, sizeof(from)); - - outbuflen = 0; -} - -void -dnsd_forceack(int fd) -{ - dnsd_send(fd, delayed_q_name, delayed_q_type, delayed_q_id, delayed_q_from); - delayed_q_id = 0; -} - -struct packet -{ - int len; - int offset; - char data[64*1024]; -}; - -static int -decodepacket(const char *name, struct packet *packet) -{ - int r; - int len; - int last; - int ping; - char *dp; - char *domain; - const char *np; - - len = 0; - last = (name[0] == '1'); - ping = (name[0] == 'p' || name[0] == 'P'); - - domain = strstr(name, topdomain); - - if (!ping && domain) { - np = name + 1; - dp = packet->data + packet->offset; - - while(np < domain) { - if(*np == '.') { - np++; - continue; - } - - sscanf(np, "%02X", &r); - *dp++ = (char)r; - np+=2; - len++; - } - - packet->len += len; - packet->offset += len; - } - - if(last) { - len = packet->len; - packet->len = packet->offset = 0; - } else { - len = 0; - } - - return len; -} - -struct packet packetbuf; - -int -dnsd_read(int fd, char *buf, int buflen) -{ - int r; - short id; - short type; - short class; - short qdcount; - char *data; - char name[255]; - HEADER *header; - socklen_t addrlen; - char packet[64*1024]; - struct sockaddr_in from; - - addrlen = sizeof(struct sockaddr); - r = recvfrom(fd, packet, sizeof(packet), 0, (struct sockaddr*)&from, &addrlen); - - //printf("Read %d bytes DNS query from %s\n", r, inet_ntoa(from.sin_addr)); - - if(r == -1) { - perror("recvfrom"); - } else { - header = (HEADER*)packet; - - id = ntohs(header->id); - - data = packet + sizeof(HEADER); - - if(!header->qr) { - qdcount = ntohs(header->qdcount); - - if(qdcount == 1) { - bzero(name, sizeof(name)); - READNAME(packet, name, data); - READSHORT(type, data); - READSHORT(class, data); - - if (dnsd_haspacket()) { - dnsd_send(fd, name, type, id, from); - } else { - // Store needed info about delayed response - strncpy(delayed_q_name, name, 256); - delayed_q_type = type; - delayed_q_id = id; - delayed_q_fromlen = addrlen; - memcpy((struct sockaddr*)&delayed_q_from, (struct sockaddr*)&from, addrlen); - } - - r = decodepacket(name, &packetbuf); - - memcpy(buf, packetbuf.data, r); - - return r; - } - } - } - - return 0; -} diff --git a/dnsd.h b/dnsd.h deleted file mode 100644 index 6eaa2a4..0000000 --- a/dnsd.h +++ /dev/null @@ -1,33 +0,0 @@ -/* - * Copyright (c) 2006 Bjorn Andersson , Erik Ekman - * - * Permission to use, copy, modify, and distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. - */ - -#ifndef _DNSD_H_ -#define _DNSD_H_ - -extern struct sockaddr_in peer; - -int open_dnsd(const char *); -void close_dnsd(int); - -int dnsd_read(int, char *, int); - -int dnsd_haspacket(); -int dnsd_hasack(); -void dnsd_forceack(int); -void dnsd_queuepacket(const char *, const int); - - -#endif /* _DNSD_H_ */ diff --git a/iodined.c b/iodined.c index 288d825..c02ac62 100644 --- a/iodined.c +++ b/iodined.c @@ -30,7 +30,6 @@ #include "tun.h" #include "dns.h" -#include "dnsd.h" #ifndef MAX #define MAX(a,b) ((a)>(b)?(a):(b))