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danicoin/external/unbound/testcode/testpkts.c
Riccardo Spagni 1f49833d4f
update unbound from upstream
2015-04-02 11:16:18 +02:00

1428 lines
38 KiB
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/*
* testpkts. Data file parse for test packets, and query matching.
*
* Data storage for specially crafted replies for testing purposes.
*
* (c) NLnet Labs, 2005, 2006, 2007, 2008
* See the file LICENSE for the license
*/
/**
* \file
* This is a debugging aid. It is not efficient, especially
* with a long config file, but it can give any reply to any query.
* This can help the developer pre-script replies for queries.
*
* You can specify a packet RR by RR with header flags to return.
*
* Missing features:
* - matching content different from reply content.
* - find way to adjust mangled packets?
*/
#include "config.h"
struct sockaddr_storage;
#include <errno.h>
#include <stdarg.h>
#include <ctype.h>
#include "testcode/testpkts.h"
#include "util/net_help.h"
#include "sldns/sbuffer.h"
#include "sldns/rrdef.h"
#include "sldns/pkthdr.h"
#include "sldns/str2wire.h"
#include "sldns/wire2str.h"
/** max size of a packet */
#define MAX_PACKETLEN 65536
/** max line length */
#define MAX_LINE 10240
/** string to show in warnings and errors */
static const char* prog_name = "testpkts";
#ifndef UTIL_LOG_H
/** verbosity definition for compat */
enum verbosity_value { NO_VERBOSE=0 };
#endif
/** logging routine, provided by caller */
void verbose(enum verbosity_value lvl, const char* msg, ...) ATTR_FORMAT(printf, 2, 3);
/** print error and exit */
static void error(const char* msg, ...)
{
va_list args;
va_start(args, msg);
fprintf(stderr, "%s error: ", prog_name);
vfprintf(stderr, msg, args);
fprintf(stderr, "\n");
fflush(stderr);
va_end(args);
exit(EXIT_FAILURE);
}
/** return if string is empty or comment */
static int isendline(char c)
{
if(c == ';' || c == '#'
|| c == '\n' || c == 0)
return 1;
return 0;
}
/** true if the string starts with the keyword given. Moves the str ahead.
* @param str: before keyword, afterwards after keyword and spaces.
* @param keyword: the keyword to match
* @return: true if keyword present. False otherwise, and str unchanged.
*/
static int str_keyword(char** str, const char* keyword)
{
size_t len = strlen(keyword);
assert(str && keyword);
if(strncmp(*str, keyword, len) != 0)
return 0;
*str += len;
while(isspace((unsigned char)**str))
(*str)++;
return 1;
}
/** Add reply packet to entry */
static struct reply_packet*
entry_add_reply(struct entry* entry)
{
struct reply_packet* pkt = (struct reply_packet*)malloc(
sizeof(struct reply_packet));
struct reply_packet ** p = &entry->reply_list;
if(!pkt) error("out of memory");
pkt->next = NULL;
pkt->packet_sleep = 0;
pkt->reply_pkt = NULL;
pkt->reply_from_hex = NULL;
/* link at end */
while(*p)
p = &((*p)->next);
*p = pkt;
return pkt;
}
/** parse MATCH line */
static void matchline(char* line, struct entry* e)
{
char* parse = line;
while(*parse) {
if(isendline(*parse))
return;
if(str_keyword(&parse, "opcode")) {
e->match_opcode = 1;
} else if(str_keyword(&parse, "qtype")) {
e->match_qtype = 1;
} else if(str_keyword(&parse, "qname")) {
e->match_qname = 1;
} else if(str_keyword(&parse, "subdomain")) {
e->match_subdomain = 1;
} else if(str_keyword(&parse, "all")) {
e->match_all = 1;
} else if(str_keyword(&parse, "ttl")) {
e->match_ttl = 1;
} else if(str_keyword(&parse, "DO")) {
e->match_do = 1;
} else if(str_keyword(&parse, "noedns")) {
e->match_noedns = 1;
} else if(str_keyword(&parse, "UDP")) {
e->match_transport = transport_udp;
} else if(str_keyword(&parse, "TCP")) {
e->match_transport = transport_tcp;
} else if(str_keyword(&parse, "serial")) {
e->match_serial = 1;
if(*parse != '=' && *parse != ':')
error("expected = or : in MATCH: %s", line);
parse++;
e->ixfr_soa_serial = (uint32_t)strtol(parse, (char**)&parse, 10);
while(isspace((unsigned char)*parse))
parse++;
} else {
error("could not parse MATCH: '%s'", parse);
}
}
}
/** parse REPLY line */
static void replyline(char* line, uint8_t* reply, size_t reply_len,
int* do_flag)
{
char* parse = line;
if(reply_len < LDNS_HEADER_SIZE) error("packet too short for header");
while(*parse) {
if(isendline(*parse))
return;
/* opcodes */
if(str_keyword(&parse, "QUERY")) {
LDNS_OPCODE_SET(reply, LDNS_PACKET_QUERY);
} else if(str_keyword(&parse, "IQUERY")) {
LDNS_OPCODE_SET(reply, LDNS_PACKET_IQUERY);
} else if(str_keyword(&parse, "STATUS")) {
LDNS_OPCODE_SET(reply, LDNS_PACKET_STATUS);
} else if(str_keyword(&parse, "NOTIFY")) {
LDNS_OPCODE_SET(reply, LDNS_PACKET_NOTIFY);
} else if(str_keyword(&parse, "UPDATE")) {
LDNS_OPCODE_SET(reply, LDNS_PACKET_UPDATE);
/* rcodes */
} else if(str_keyword(&parse, "NOERROR")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NOERROR);
} else if(str_keyword(&parse, "FORMERR")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_FORMERR);
} else if(str_keyword(&parse, "SERVFAIL")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_SERVFAIL);
} else if(str_keyword(&parse, "NXDOMAIN")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NXDOMAIN);
} else if(str_keyword(&parse, "NOTIMPL")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NOTIMPL);
} else if(str_keyword(&parse, "REFUSED")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_REFUSED);
} else if(str_keyword(&parse, "YXDOMAIN")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_YXDOMAIN);
} else if(str_keyword(&parse, "YXRRSET")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_YXRRSET);
} else if(str_keyword(&parse, "NXRRSET")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NXRRSET);
} else if(str_keyword(&parse, "NOTAUTH")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NOTAUTH);
} else if(str_keyword(&parse, "NOTZONE")) {
LDNS_RCODE_SET(reply, LDNS_RCODE_NOTZONE);
/* flags */
} else if(str_keyword(&parse, "QR")) {
LDNS_QR_SET(reply);
} else if(str_keyword(&parse, "AA")) {
LDNS_AA_SET(reply);
} else if(str_keyword(&parse, "TC")) {
LDNS_TC_SET(reply);
} else if(str_keyword(&parse, "RD")) {
LDNS_RD_SET(reply);
} else if(str_keyword(&parse, "CD")) {
LDNS_CD_SET(reply);
} else if(str_keyword(&parse, "RA")) {
LDNS_RA_SET(reply);
} else if(str_keyword(&parse, "AD")) {
LDNS_AD_SET(reply);
} else if(str_keyword(&parse, "DO")) {
*do_flag = 1;
} else {
error("could not parse REPLY: '%s'", parse);
}
}
}
/** parse ADJUST line */
static void adjustline(char* line, struct entry* e,
struct reply_packet* pkt)
{
char* parse = line;
while(*parse) {
if(isendline(*parse))
return;
if(str_keyword(&parse, "copy_id")) {
e->copy_id = 1;
} else if(str_keyword(&parse, "copy_query")) {
e->copy_query = 1;
} else if(str_keyword(&parse, "sleep=")) {
e->sleeptime = (unsigned int) strtol(parse, (char**)&parse, 10);
while(isspace((unsigned char)*parse))
parse++;
} else if(str_keyword(&parse, "packet_sleep=")) {
pkt->packet_sleep = (unsigned int) strtol(parse, (char**)&parse, 10);
while(isspace((unsigned char)*parse))
parse++;
} else {
error("could not parse ADJUST: '%s'", parse);
}
}
}
/** create new entry */
static struct entry* new_entry()
{
struct entry* e = (struct entry*)malloc(sizeof(struct entry));
if(!e) error("out of memory");
memset(e, 0, sizeof(*e));
e->match_opcode = 0;
e->match_qtype = 0;
e->match_qname = 0;
e->match_subdomain = 0;
e->match_all = 0;
e->match_ttl = 0;
e->match_do = 0;
e->match_noedns = 0;
e->match_serial = 0;
e->ixfr_soa_serial = 0;
e->match_transport = transport_any;
e->reply_list = NULL;
e->copy_id = 0;
e->copy_query = 0;
e->sleeptime = 0;
e->next = NULL;
return e;
}
/**
* Converts a hex string to binary data
* @param hexstr: string of hex.
* @param len: is the length of the string
* @param buf: is the buffer to store the result in
* @param offset: is the starting position in the result buffer
* @param buf_len: is the length of buf.
* @return This function returns the length of the result
*/
static size_t
hexstr2bin(char *hexstr, int len, uint8_t *buf, size_t offset, size_t buf_len)
{
char c;
int i;
uint8_t int8 = 0;
int sec = 0;
size_t bufpos = 0;
if (len % 2 != 0) {
return 0;
}
for (i=0; i<len; i++) {
c = hexstr[i];
/* case insensitive, skip spaces */
if (c != ' ') {
if (c >= '0' && c <= '9') {
int8 += c & 0x0f;
} else if (c >= 'a' && c <= 'z') {
int8 += (c & 0x0f) + 9;
} else if (c >= 'A' && c <= 'Z') {
int8 += (c & 0x0f) + 9;
} else {
return 0;
}
if (sec == 0) {
int8 = int8 << 4;
sec = 1;
} else {
if (bufpos + offset + 1 <= buf_len) {
buf[bufpos+offset] = int8;
int8 = 0;
sec = 0;
bufpos++;
} else {
fprintf(stderr, "Buffer too small in hexstr2bin");
}
}
}
}
return bufpos;
}
/** convert hex buffer to binary buffer */
static sldns_buffer *
hex_buffer2wire(sldns_buffer *data_buffer)
{
sldns_buffer *wire_buffer = NULL;
int c;
/* stat hack
* 0 = normal
* 1 = comment (skip to end of line)
* 2 = unprintable character found, read binary data directly
*/
size_t data_buf_pos = 0;
int state = 0;
uint8_t *hexbuf;
int hexbufpos = 0;
size_t wirelen;
uint8_t *data_wire = (uint8_t *) sldns_buffer_begin(data_buffer);
uint8_t *wire = (uint8_t*)malloc(MAX_PACKETLEN);
if(!wire) error("out of memory");
hexbuf = (uint8_t*)malloc(MAX_PACKETLEN);
if(!hexbuf) error("out of memory");
for (data_buf_pos = 0; data_buf_pos < sldns_buffer_position(data_buffer); data_buf_pos++) {
c = (int) data_wire[data_buf_pos];
if (state < 2 && !isascii((unsigned char)c)) {
/*verbose("non ascii character found in file: (%d) switching to raw mode\n", c);*/
state = 2;
}
switch (state) {
case 0:
if ( (c >= '0' && c <= '9') ||
(c >= 'a' && c <= 'f') ||
(c >= 'A' && c <= 'F') )
{
if (hexbufpos >= MAX_PACKETLEN) {
error("buffer overflow");
free(hexbuf);
return 0;
}
hexbuf[hexbufpos] = (uint8_t) c;
hexbufpos++;
} else if (c == ';') {
state = 1;
} else if (c == ' ' || c == '\t' || c == '\n') {
/* skip whitespace */
}
break;
case 1:
if (c == '\n' || c == EOF) {
state = 0;
}
break;
case 2:
if (hexbufpos >= MAX_PACKETLEN) {
error("buffer overflow");
free(hexbuf);
return 0;
}
hexbuf[hexbufpos] = (uint8_t) c;
hexbufpos++;
break;
}
}
if (hexbufpos >= MAX_PACKETLEN) {
/*verbose("packet size reached\n");*/
}
/* lenient mode: length must be multiple of 2 */
if (hexbufpos % 2 != 0) {
if (hexbufpos >= MAX_PACKETLEN) {
error("buffer overflow");
free(hexbuf);
return 0;
}
hexbuf[hexbufpos] = (uint8_t) '0';
hexbufpos++;
}
if (state < 2) {
wirelen = hexstr2bin((char *) hexbuf, hexbufpos, wire, 0, MAX_PACKETLEN);
wire_buffer = sldns_buffer_new(wirelen);
sldns_buffer_new_frm_data(wire_buffer, wire, wirelen);
} else {
error("Incomplete hex data, not at byte boundary\n");
}
free(wire);
free(hexbuf);
return wire_buffer;
}
/** parse ORIGIN */
static void
get_origin(const char* name, struct sldns_file_parse_state* pstate, char* parse)
{
/* snip off rest of the text so as to make the parse work in ldns */
char* end;
char store;
int status;
end=parse;
while(!isspace((unsigned char)*end) && !isendline(*end))
end++;
store = *end;
*end = 0;
verbose(3, "parsing '%s'\n", parse);
status = sldns_str2wire_dname_buf(parse, pstate->origin,
&pstate->origin_len);
*end = store;
if(status != 0)
error("%s line %d:\n\t%s: %s", name, pstate->lineno,
sldns_get_errorstr_parse(status), parse);
}
/** add RR to packet */
static void add_rr(char* rrstr, uint8_t* pktbuf, size_t pktsize,
size_t* pktlen, struct sldns_file_parse_state* pstate,
sldns_pkt_section add_section, const char* fname)
{
/* it must be a RR, parse and add to packet. */
size_t rr_len = pktsize - *pktlen;
size_t dname_len = 0;
int status;
uint8_t* origin = pstate->origin_len?pstate->origin:0;
uint8_t* prev = pstate->prev_rr_len?pstate->prev_rr:0;
if(*pktlen > pktsize || *pktlen < LDNS_HEADER_SIZE)
error("packet overflow");
/* parse RR */
if(add_section == LDNS_SECTION_QUESTION)
status = sldns_str2wire_rr_question_buf(rrstr, pktbuf+*pktlen,
&rr_len, &dname_len, origin, pstate->origin_len,
prev, pstate->prev_rr_len);
else status = sldns_str2wire_rr_buf(rrstr, pktbuf+*pktlen, &rr_len,
&dname_len, pstate->default_ttl, origin,
pstate->origin_len, prev, pstate->prev_rr_len);
if(status != 0)
error("%s line %d:%d %s\n\t%s", fname, pstate->lineno,
LDNS_WIREPARSE_OFFSET(status),
sldns_get_errorstr_parse(status), rrstr);
*pktlen += rr_len;
/* increase RR count */
if(add_section == LDNS_SECTION_QUESTION)
sldns_write_uint16(pktbuf+4, LDNS_QDCOUNT(pktbuf)+1);
else if(add_section == LDNS_SECTION_ANSWER)
sldns_write_uint16(pktbuf+6, LDNS_ANCOUNT(pktbuf)+1);
else if(add_section == LDNS_SECTION_AUTHORITY)
sldns_write_uint16(pktbuf+8, LDNS_NSCOUNT(pktbuf)+1);
else if(add_section == LDNS_SECTION_ADDITIONAL)
sldns_write_uint16(pktbuf+10, LDNS_ARCOUNT(pktbuf)+1);
else error("internal error bad section %d", (int)add_section);
}
/* add EDNS 4096 DO opt record */
static void
add_do_flag(uint8_t* pktbuf, size_t pktsize, size_t* pktlen)
{
uint8_t edns[] = {0x00, /* root label */
0x00, LDNS_RR_TYPE_OPT, /* type */
0x10, 0x00, /* class is UDPSIZE 4096 */
0x00, /* TTL[0] is ext rcode */
0x00, /* TTL[1] is edns version */
0x80, 0x00, /* TTL[2-3] is edns flags, DO */
0x00, 0x00 /* rdatalength (0 options) */
};
if(*pktlen < LDNS_HEADER_SIZE)
return;
if(*pktlen + sizeof(edns) > pktsize)
error("not enough space for EDNS OPT record");
memmove(pktbuf+*pktlen, edns, sizeof(edns));
sldns_write_uint16(pktbuf+10, LDNS_ARCOUNT(pktbuf)+1);
*pktlen += sizeof(edns);
}
/* Reads one entry from file. Returns entry or NULL on error. */
struct entry*
read_entry(FILE* in, const char* name, struct sldns_file_parse_state* pstate,
int skip_whitespace)
{
struct entry* current = NULL;
char line[MAX_LINE];
char* parse;
sldns_pkt_section add_section = LDNS_SECTION_QUESTION;
struct reply_packet *cur_reply = NULL;
int reading_hex = 0;
sldns_buffer* hex_data_buffer = NULL;
uint8_t pktbuf[MAX_PACKETLEN];
size_t pktlen = LDNS_HEADER_SIZE;
int do_flag = 0; /* DO flag in EDNS */
memset(pktbuf, 0, pktlen); /* ID = 0, FLAGS="", and rr counts 0 */
while(fgets(line, (int)sizeof(line), in) != NULL) {
line[MAX_LINE-1] = 0;
parse = line;
pstate->lineno++;
while(isspace((unsigned char)*parse))
parse++;
/* test for keywords */
if(isendline(*parse))
continue; /* skip comment and empty lines */
if(str_keyword(&parse, "ENTRY_BEGIN")) {
if(current) {
error("%s line %d: previous entry does not ENTRY_END",
name, pstate->lineno);
}
current = new_entry();
current->lineno = pstate->lineno;
cur_reply = entry_add_reply(current);
continue;
} else if(str_keyword(&parse, "$ORIGIN")) {
get_origin(name, pstate, parse);
continue;
} else if(str_keyword(&parse, "$TTL")) {
pstate->default_ttl = (uint32_t)atoi(parse);
continue;
}
/* working inside an entry */
if(!current) {
error("%s line %d: expected ENTRY_BEGIN but got %s",
name, pstate->lineno, line);
}
if(str_keyword(&parse, "MATCH")) {
matchline(parse, current);
} else if(str_keyword(&parse, "REPLY")) {
replyline(parse, pktbuf, pktlen, &do_flag);
} else if(str_keyword(&parse, "ADJUST")) {
adjustline(parse, current, cur_reply);
} else if(str_keyword(&parse, "EXTRA_PACKET")) {
cur_reply = entry_add_reply(current);
} else if(str_keyword(&parse, "SECTION")) {
if(str_keyword(&parse, "QUESTION"))
add_section = LDNS_SECTION_QUESTION;
else if(str_keyword(&parse, "ANSWER"))
add_section = LDNS_SECTION_ANSWER;
else if(str_keyword(&parse, "AUTHORITY"))
add_section = LDNS_SECTION_AUTHORITY;
else if(str_keyword(&parse, "ADDITIONAL"))
add_section = LDNS_SECTION_ADDITIONAL;
else error("%s line %d: bad section %s", name, pstate->lineno, parse);
} else if(str_keyword(&parse, "HEX_ANSWER_BEGIN")) {
hex_data_buffer = sldns_buffer_new(MAX_PACKETLEN);
reading_hex = 1;
} else if(str_keyword(&parse, "HEX_ANSWER_END")) {
if(!reading_hex) {
error("%s line %d: HEX_ANSWER_END read but no HEX_ANSWER_BEGIN keyword seen", name, pstate->lineno);
}
reading_hex = 0;
cur_reply->reply_from_hex = hex_buffer2wire(hex_data_buffer);
sldns_buffer_free(hex_data_buffer);
hex_data_buffer = NULL;
} else if(str_keyword(&parse, "ENTRY_END")) {
if(hex_data_buffer)
sldns_buffer_free(hex_data_buffer);
if(pktlen != 0) {
if(do_flag)
add_do_flag(pktbuf, sizeof(pktbuf),
&pktlen);
cur_reply->reply_pkt = memdup(pktbuf, pktlen);
cur_reply->reply_len = pktlen;
if(!cur_reply->reply_pkt)
error("out of memory");
}
return current;
} else if(reading_hex) {
sldns_buffer_printf(hex_data_buffer, "%s", line);
} else {
add_rr(skip_whitespace?parse:line, pktbuf,
sizeof(pktbuf), &pktlen, pstate, add_section,
name);
}
}
if (reading_hex) {
error("%s: End of file reached while still reading hex, "
"missing HEX_ANSWER_END\n", name);
}
if(current) {
error("%s: End of file reached while reading entry. "
"missing ENTRY_END\n", name);
}
return 0;
}
/* reads the canned reply file and returns a list of structs */
struct entry*
read_datafile(const char* name, int skip_whitespace)
{
struct entry* list = NULL;
struct entry* last = NULL;
struct entry* current = NULL;
FILE *in;
struct sldns_file_parse_state pstate;
int entry_num = 0;
memset(&pstate, 0, sizeof(pstate));
if((in=fopen(name, "r")) == NULL) {
error("could not open file %s: %s", name, strerror(errno));
}
while((current = read_entry(in, name, &pstate, skip_whitespace)))
{
if(last)
last->next = current;
else list = current;
last = current;
entry_num ++;
}
verbose(1, "%s: Read %d entries\n", prog_name, entry_num);
fclose(in);
return list;
}
/** get qtype from packet */
static sldns_rr_type get_qtype(uint8_t* pkt, size_t pktlen)
{
uint8_t* d;
size_t dl, sl=0;
char* snull = NULL;
if(pktlen < LDNS_HEADER_SIZE)
return 0;
if(LDNS_QDCOUNT(pkt) == 0)
return 0;
/* skip over dname with dname-scan routine */
d = pkt+LDNS_HEADER_SIZE;
dl = pktlen-LDNS_HEADER_SIZE;
(void)sldns_wire2str_dname_scan(&d, &dl, &snull, &sl, pkt, pktlen);
if(dl < 2)
return 0;
return sldns_read_uint16(d);
}
/** get qtype from packet */
static size_t get_qname_len(uint8_t* pkt, size_t pktlen)
{
uint8_t* d;
size_t dl, sl=0;
char* snull = NULL;
if(pktlen < LDNS_HEADER_SIZE)
return 0;
if(LDNS_QDCOUNT(pkt) == 0)
return 0;
/* skip over dname with dname-scan routine */
d = pkt+LDNS_HEADER_SIZE;
dl = pktlen-LDNS_HEADER_SIZE;
(void)sldns_wire2str_dname_scan(&d, &dl, &snull, &sl, pkt, pktlen);
return pktlen-dl-LDNS_HEADER_SIZE;
}
/** returns owner from packet */
static uint8_t* get_qname(uint8_t* pkt, size_t pktlen)
{
if(pktlen < LDNS_HEADER_SIZE)
return NULL;
if(LDNS_QDCOUNT(pkt) == 0)
return NULL;
return pkt+LDNS_HEADER_SIZE;
}
/** returns opcode from packet */
static int get_opcode(uint8_t* pkt, size_t pktlen)
{
if(pktlen < LDNS_HEADER_SIZE)
return 0;
return (int)LDNS_OPCODE_WIRE(pkt);
}
/** get authority section SOA serial value */
static uint32_t get_serial(uint8_t* p, size_t plen)
{
uint8_t* walk = p;
size_t walk_len = plen, sl=0;
char* snull = NULL;
uint16_t i;
if(walk_len < LDNS_HEADER_SIZE)
return 0;
walk += LDNS_HEADER_SIZE;
walk_len -= LDNS_HEADER_SIZE;
/* skip other records with wire2str_scan */
for(i=0; i < LDNS_QDCOUNT(p); i++)
(void)sldns_wire2str_rrquestion_scan(&walk, &walk_len,
&snull, &sl, p, plen);
for(i=0; i < LDNS_ANCOUNT(p); i++)
(void)sldns_wire2str_rr_scan(&walk, &walk_len, &snull, &sl,
p, plen);
/* walk through authority section */
for(i=0; i < LDNS_NSCOUNT(p); i++) {
/* if this is SOA then get serial, skip compressed dname */
uint8_t* dstart = walk;
size_t dlen = walk_len;
(void)sldns_wire2str_dname_scan(&dstart, &dlen, &snull, &sl,
p, plen);
if(dlen >= 2 && sldns_read_uint16(dstart) == LDNS_RR_TYPE_SOA) {
/* skip type, class, TTL, rdatalen */
if(dlen < 10)
return 0;
if(dlen < 10 + (size_t)sldns_read_uint16(dstart+8))
return 0;
dstart += 10;
dlen -= 10;
/* check third rdf */
(void)sldns_wire2str_dname_scan(&dstart, &dlen, &snull,
&sl, p, plen);
(void)sldns_wire2str_dname_scan(&dstart, &dlen, &snull,
&sl, p, plen);
if(dlen < 4)
return 0;
verbose(3, "found serial %u in msg. ",
(int)sldns_read_uint32(dstart));
return sldns_read_uint32(dstart);
}
/* move to next RR */
(void)sldns_wire2str_rr_scan(&walk, &walk_len, &snull, &sl,
p, plen);
}
return 0;
}
/** get ptr to EDNS OPT record (and remaining length); behind the type u16 */
static int
pkt_find_edns_opt(uint8_t** p, size_t* plen)
{
/* walk over the packet with scan routines */
uint8_t* w = *p;
size_t wlen = *plen, sl=0;
char* snull = NULL;
uint16_t i;
if(wlen < LDNS_HEADER_SIZE)
return 0;
w += LDNS_HEADER_SIZE;
wlen -= LDNS_HEADER_SIZE;
/* skip other records with wire2str_scan */
for(i=0; i < LDNS_QDCOUNT(p); i++)
(void)sldns_wire2str_rrquestion_scan(&w, &wlen, &snull, &sl,
*p, *plen);
for(i=0; i < LDNS_ANCOUNT(p); i++)
(void)sldns_wire2str_rr_scan(&w, &wlen, &snull, &sl, *p, *plen);
for(i=0; i < LDNS_NSCOUNT(p); i++)
(void)sldns_wire2str_rr_scan(&w, &wlen, &snull, &sl, *p, *plen);
/* walk through additional section */
for(i=0; i < LDNS_ARCOUNT(p); i++) {
/* if this is OPT then done */
uint8_t* dstart = w;
size_t dlen = wlen;
(void)sldns_wire2str_dname_scan(&dstart, &dlen, &snull, &sl,
*p, *plen);
if(dlen >= 2 && sldns_read_uint16(dstart) == LDNS_RR_TYPE_OPT) {
*p = dstart+2;
*plen = dlen-2;
return 1;
}
/* move to next RR */
(void)sldns_wire2str_rr_scan(&w, &wlen, &snull, &sl, *p, *plen);
}
return 0;
}
/** return true if the packet has EDNS OPT record */
static int
get_has_edns(uint8_t* pkt, size_t len)
{
/* use arguments as temporary variables */
return pkt_find_edns_opt(&pkt, &len);
}
/** return true if the DO flag is set */
static int
get_do_flag(uint8_t* pkt, size_t len)
{
uint16_t edns_bits;
uint8_t* walk = pkt;
size_t walk_len = len;
if(pkt_find_edns_opt(&walk, &walk_len)) {
return 1;
}
if(walk_len < 6)
return 0; /* malformed */
edns_bits = sldns_read_uint16(walk+4);
return (int)(edns_bits&LDNS_EDNS_MASK_DO_BIT);
}
/** zero TTLs in packet */
static void
zerottls(uint8_t* pkt, size_t pktlen)
{
uint8_t* walk = pkt;
size_t walk_len = pktlen, sl=0;
char* snull = NULL;
uint16_t i;
uint16_t num = LDNS_ANCOUNT(pkt)+LDNS_NSCOUNT(pkt)+LDNS_ARCOUNT(pkt);
if(walk_len < LDNS_HEADER_SIZE)
return;
walk += LDNS_HEADER_SIZE;
walk_len -= LDNS_HEADER_SIZE;
for(i=0; i < LDNS_QDCOUNT(pkt); i++)
(void)sldns_wire2str_rrquestion_scan(&walk, &walk_len,
&snull, &sl, pkt, pktlen);
for(i=0; i < num; i++) {
/* wipe TTL */
uint8_t* dstart = walk;
size_t dlen = walk_len;
(void)sldns_wire2str_dname_scan(&dstart, &dlen, &snull, &sl,
pkt, pktlen);
if(dlen < 8)
return;
sldns_write_uint32(dstart+4, 0);
/* go to next RR */
(void)sldns_wire2str_rr_scan(&walk, &walk_len, &snull, &sl,
pkt, pktlen);
}
}
/** get one line (\n) from a string, move next to after the \n, zero \n */
static int
get_line(char** s, char** n)
{
/* at end of string? end */
if(*n == NULL || **n == 0)
return 0;
/* result starts at next string */
*s = *n;
/* find \n after that */
*n = strchr(*s, '\n');
if(*n && **n != 0) {
/* terminate line */
(*n)[0] = 0;
(*n)++;
}
return 1;
}
/** match two RR sections without ordering */
static int
match_noloc_section(char** q, char** nq, char** p, char** np, uint16_t num)
{
/* for max number of RRs in packet */
const uint16_t numarray = 3000;
char* qlines[numarray], *plines[numarray];
uint16_t i, j, numq=0, nump=0;
if(num > numarray) fatal_exit("too many RRs");
/* gather lines */
for(i=0; i<num; i++) {
get_line(q, nq);
get_line(p, np);
qlines[numq++] = *q;
plines[nump++] = *p;
}
/* see if they are all present in the other */
for(i=0; i<num; i++) {
int found = 0;
for(j=0; j<num; j++) {
if(strcmp(qlines[i], plines[j]) == 0) {
found = 1;
break;
}
}
if(!found) {
verbose(3, "comparenoloc: failed for %s", qlines[i]);
return 0;
}
}
return 1;
}
/** match two strings for unordered equality of RRs and everything else */
static int
match_noloc(char* q, char* p, uint8_t* q_pkt, size_t q_pkt_len,
uint8_t* p_pkt, size_t p_pkt_len)
{
char* nq = q, *np = p;
/* if no header, compare bytes */
if(p_pkt_len < LDNS_HEADER_SIZE || q_pkt_len < LDNS_HEADER_SIZE) {
if(p_pkt_len != q_pkt_len) return 0;
return memcmp(p, q, p_pkt_len);
}
/* compare RR counts */
if(LDNS_QDCOUNT(p_pkt) != LDNS_QDCOUNT(q_pkt))
return 0;
if(LDNS_ANCOUNT(p_pkt) != LDNS_ANCOUNT(q_pkt))
return 0;
if(LDNS_NSCOUNT(p_pkt) != LDNS_NSCOUNT(q_pkt))
return 0;
if(LDNS_ARCOUNT(p_pkt) != LDNS_ARCOUNT(q_pkt))
return 0;
/* get a line from both; compare; at sections do section */
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) {
/* header line opcode, rcode, id */
return 0;
}
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) {
/* header flags, rr counts */
return 0;
}
/* ;; QUESTION SECTION */
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
if(!match_noloc_section(&q, &nq, &p, &np, LDNS_QDCOUNT(p_pkt)))
return 0;
/* empty line and ;; ANSWER SECTION */
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
if(!match_noloc_section(&q, &nq, &p, &np, LDNS_ANCOUNT(p_pkt)))
return 0;
/* empty line and ;; AUTHORITY SECTION */
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
if(!match_noloc_section(&q, &nq, &p, &np, LDNS_NSCOUNT(p_pkt)))
return 0;
/* empty line and ;; ADDITIONAL SECTION */
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
get_line(&q, &nq);
get_line(&p, &np);
if(strcmp(q, p) != 0) return 0;
if(!match_noloc_section(&q, &nq, &p, &np, LDNS_ARCOUNT(p_pkt)))
return 0;
return 1;
}
/** lowercase domain name - does not follow compression pointers */
static void lowercase_dname(uint8_t** p, size_t* remain)
{
unsigned i, llen;
if(*remain == 0) return;
while(**p != 0) {
/* compressed? */
if((**p & 0xc0) == 0xc0) {
*p += 2;
*remain -= 2;
return;
}
llen = (unsigned int)**p;
*p += 1;
*remain -= 1;
if(*remain < llen)
llen = (unsigned int)*remain;
for(i=0; i<llen; i++) {
(*p)[i] = (uint8_t)tolower((int)(*p)[i]);
}
*p += llen;
*remain -= llen;
if(*remain == 0) return;
}
/* skip root label */
*p += 1;
*remain -= 1;
}
/** lowercase rdata of type */
static void lowercase_rdata(uint8_t** p, size_t* remain,
uint16_t rdatalen, uint16_t t)
{
const sldns_rr_descriptor *desc = sldns_rr_descript(t);
uint8_t dname_count = 0;
size_t i = 0;
size_t rdataremain = rdatalen;
if(!desc) {
/* unknown type */
*p += rdatalen;
*remain -= rdatalen;
return;
}
while(dname_count < desc->_dname_count) {
sldns_rdf_type f = sldns_rr_descriptor_field_type(desc, i++);
if(f == LDNS_RDF_TYPE_DNAME) {
lowercase_dname(p, &rdataremain);
dname_count++;
} else if(f == LDNS_RDF_TYPE_STR) {
uint8_t len;
if(rdataremain == 0) return;
len = **p;
*p += len+1;
rdataremain -= len+1;
} else {
int len = 0;
switch(f) {
case LDNS_RDF_TYPE_CLASS:
case LDNS_RDF_TYPE_ALG:
case LDNS_RDF_TYPE_INT8:
len = 1;
break;
case LDNS_RDF_TYPE_INT16:
case LDNS_RDF_TYPE_TYPE:
case LDNS_RDF_TYPE_CERT_ALG:
len = 2;
break;
case LDNS_RDF_TYPE_INT32:
case LDNS_RDF_TYPE_TIME:
case LDNS_RDF_TYPE_A:
case LDNS_RDF_TYPE_PERIOD:
len = 4;
break;
case LDNS_RDF_TYPE_TSIGTIME:
len = 6;
break;
case LDNS_RDF_TYPE_AAAA:
len = 16;
break;
default: error("bad rdf type in lowercase %d", (int)f);
}
*p += len;
rdataremain -= len;
}
}
/* skip remainder of rdata */
*p += rdataremain;
*remain -= rdatalen;
}
/** lowercase all names in the message */
static void lowercase_pkt(uint8_t* pkt, size_t pktlen)
{
uint16_t i;
uint8_t* p = pkt;
size_t remain = pktlen;
uint16_t t, rdatalen;
if(pktlen < LDNS_HEADER_SIZE)
return;
p += LDNS_HEADER_SIZE;
remain -= LDNS_HEADER_SIZE;
for(i=0; i<LDNS_QDCOUNT(pkt); i++) {
lowercase_dname(&p, &remain);
if(remain < 4) return;
p += 4;
remain -= 4;
}
for(i=0; i<LDNS_ANCOUNT(pkt)+LDNS_NSCOUNT(pkt)+LDNS_ARCOUNT(pkt); i++) {
lowercase_dname(&p, &remain);
if(remain < 10) return;
t = sldns_read_uint16(p);
rdatalen = sldns_read_uint16(p+8);
p += 10;
remain -= 10;
if(remain < rdatalen) return;
lowercase_rdata(&p, &remain, rdatalen, t);
}
}
/** match all of the packet */
int
match_all(uint8_t* q, size_t qlen, uint8_t* p, size_t plen, int mttl,
int noloc)
{
char* qstr, *pstr;
uint8_t* qb = q, *pb = p;
int r;
/* zero TTLs */
qb = memdup(q, qlen);
pb = memdup(p, plen);
if(!qb || !pb) error("out of memory");
if(!mttl) {
zerottls(qb, qlen);
zerottls(pb, plen);
}
lowercase_pkt(qb, qlen);
lowercase_pkt(pb, plen);
qstr = sldns_wire2str_pkt(qb, qlen);
pstr = sldns_wire2str_pkt(pb, plen);
if(!qstr || !pstr) error("cannot pkt2string");
r = (strcmp(qstr, pstr) == 0);
if(!r) {
/* remove ;; MSG SIZE (at end of string) */
char* s = strstr(qstr, ";; MSG SIZE");
if(s) *s=0;
s = strstr(pstr, ";; MSG SIZE");
if(s) *s=0;
r = (strcmp(qstr, pstr) == 0);
if(!r && !noloc) {
/* we are going to fail see if it is because of EDNS */
char* a = strstr(qstr, "; EDNS");
char* b = strstr(pstr, "; EDNS");
if( (a&&!b) || (b&&!a) ) {
verbose(3, "mismatch in EDNS\n");
}
}
}
if(!r && noloc) {
/* check for reordered sections */
r = match_noloc(qstr, pstr, q, qlen, p, plen);
}
free(qstr);
free(pstr);
free(qb);
free(pb);
return r;
}
/** see if domain names are equal */
static int equal_dname(uint8_t* q, size_t qlen, uint8_t* p, size_t plen)
{
uint8_t* qn = get_qname(q, qlen);
uint8_t* pn = get_qname(p, plen);
char qs[512], ps[512];
size_t qslen = sizeof(qs), pslen = sizeof(ps);
char* qss = qs, *pss = ps;
if(!qn || !pn)
return 0;
(void)sldns_wire2str_dname_scan(&qn, &qlen, &qss, &qslen, q, qlen);
(void)sldns_wire2str_dname_scan(&pn, &plen, &pss, &pslen, p, plen);
return (strcmp(qs, ps) == 0);
}
/** see if domain names are subdomain q of p */
static int subdomain_dname(uint8_t* q, size_t qlen, uint8_t* p, size_t plen)
{
/* we use the tostring routines so as to test unbound's routines
* with something else */
uint8_t* qn = get_qname(q, qlen);
uint8_t* pn = get_qname(p, plen);
char qs[5120], ps[5120];
size_t qslen = sizeof(qs), pslen = sizeof(ps);
char* qss = qs, *pss = ps;
if(!qn || !pn)
return 0;
/* decompresses domain names */
(void)sldns_wire2str_dname_scan(&qn, &qlen, &qss, &qslen, q, qlen);
(void)sldns_wire2str_dname_scan(&pn, &plen, &pss, &pslen, p, plen);
/* same: false, (strict subdomain check)??? */
if(strcmp(qs, ps) == 0)
return 1;
/* qs must end in ps, at a dot, without \ in front */
qslen = strlen(qs);
pslen = strlen(ps);
if(qslen > pslen && strcmp(qs + (qslen-pslen), ps) == 0 &&
qslen + 2 >= pslen && /* space for label and dot */
qs[qslen-pslen-1] == '.') {
unsigned int slashcount = 0;
size_t i = qslen-pslen-2;
while(i>0 && qs[i]=='\\') {
i++;
slashcount++;
}
if(slashcount%1 == 1) return 0; /* . preceded by \ */
return 1;
}
return 0;
}
/* finds entry in list, or returns NULL */
struct entry*
find_match(struct entry* entries, uint8_t* query_pkt, size_t len,
enum transport_type transport)
{
struct entry* p = entries;
uint8_t* reply;
size_t rlen;
for(p=entries; p; p=p->next) {
verbose(3, "comparepkt: ");
reply = p->reply_list->reply_pkt;
rlen = p->reply_list->reply_len;
if(p->match_opcode && get_opcode(query_pkt, len) !=
get_opcode(reply, rlen)) {
verbose(3, "bad opcode\n");
continue;
}
if(p->match_qtype && get_qtype(query_pkt, len) !=
get_qtype(reply, rlen)) {
verbose(3, "bad qtype %d %d\n", get_qtype(query_pkt, len), get_qtype(reply, rlen));
continue;
}
if(p->match_qname) {
if(!equal_dname(query_pkt, len, reply, rlen)) {
verbose(3, "bad qname\n");
continue;
}
}
if(p->match_subdomain) {
if(!subdomain_dname(query_pkt, len, reply, rlen)) {
verbose(3, "bad subdomain\n");
continue;
}
}
if(p->match_serial && get_serial(query_pkt, len) != p->ixfr_soa_serial) {
verbose(3, "bad serial\n");
continue;
}
if(p->match_do && !get_do_flag(query_pkt, len)) {
verbose(3, "no DO bit set\n");
continue;
}
if(p->match_noedns && get_has_edns(query_pkt, len)) {
verbose(3, "bad; EDNS OPT present\n");
continue;
}
if(p->match_transport != transport_any && p->match_transport != transport) {
verbose(3, "bad transport\n");
continue;
}
if(p->match_all && !match_all(query_pkt, len, reply, rlen,
(int)p->match_ttl, 0)) {
verbose(3, "bad allmatch\n");
continue;
}
verbose(3, "match!\n");
return p;
}
return NULL;
}
void
adjust_packet(struct entry* match, uint8_t** answer_pkt, size_t *answer_len,
uint8_t* query_pkt, size_t query_len)
{
uint8_t* orig = *answer_pkt;
size_t origlen = *answer_len;
uint8_t* res;
size_t reslen;
/* perform the copy; if possible; must be uncompressed */
if(match->copy_query && origlen >= LDNS_HEADER_SIZE &&
query_len >= LDNS_HEADER_SIZE && LDNS_QDCOUNT(query_pkt)!=0
&& LDNS_QDCOUNT(orig)==0) {
/* no qname in output packet, insert it */
size_t dlen = get_qname_len(query_pkt, query_len);
reslen = origlen + dlen + 4;
res = (uint8_t*)malloc(reslen);
if(!res) {
verbose(1, "out of memory; send without adjust\n");
return;
}
/* copy the header, query, remainder */
memcpy(res, orig, LDNS_HEADER_SIZE);
memmove(res+LDNS_HEADER_SIZE, query_pkt+LDNS_HEADER_SIZE,
dlen+4);
memmove(res+LDNS_HEADER_SIZE+dlen+4, orig+LDNS_HEADER_SIZE,
reslen-(LDNS_HEADER_SIZE+dlen+4));
/* set QDCOUNT */
sldns_write_uint16(res+4, 1);
} else if(match->copy_query && origlen >= LDNS_HEADER_SIZE &&
query_len >= LDNS_HEADER_SIZE && LDNS_QDCOUNT(query_pkt)!=0
&& get_qname_len(orig, origlen) == 0) {
/* QDCOUNT(orig)!=0 but qlen == 0, therefore, an error */
verbose(1, "error: malformed qname; send without adjust\n");
res = memdup(orig, origlen);
reslen = origlen;
} else if(match->copy_query && origlen >= LDNS_HEADER_SIZE &&
query_len >= LDNS_HEADER_SIZE && LDNS_QDCOUNT(query_pkt)!=0
&& LDNS_QDCOUNT(orig)!=0) {
/* in this case olen != 0 and QDCOUNT(orig)!=0 */
/* copy query section */
size_t dlen = get_qname_len(query_pkt, query_len);
size_t olen = get_qname_len(orig, origlen);
reslen = origlen + dlen - olen;
res = (uint8_t*)malloc(reslen);
if(!res) {
verbose(1, "out of memory; send without adjust\n");
return;
}
/* copy the header, query, remainder */
memcpy(res, orig, LDNS_HEADER_SIZE);
memmove(res+LDNS_HEADER_SIZE, query_pkt+LDNS_HEADER_SIZE,
dlen+4);
memmove(res+LDNS_HEADER_SIZE+dlen+4,
orig+LDNS_HEADER_SIZE+olen+4,
reslen-(LDNS_HEADER_SIZE+dlen+4));
} else {
res = memdup(orig, origlen);
reslen = origlen;
}
if(!res) {
verbose(1, "out of memory; send without adjust\n");
return;
}
/* copy the ID */
if(match->copy_id && reslen >= 2)
res[1] = orig[1];
if(match->copy_id && reslen >= 1)
res[0] = orig[0];
if(match->sleeptime > 0) {
verbose(3, "sleeping for %d seconds\n", match->sleeptime);
#ifdef HAVE_SLEEP
sleep(match->sleeptime);
#else
Sleep(match->sleeptime * 1000);
#endif
}
*answer_pkt = res;
*answer_len = reslen;
}
/*
* Parses data buffer to a query, finds the correct answer
* and calls the given function for every packet to send.
*/
void
handle_query(uint8_t* inbuf, ssize_t inlen, struct entry* entries, int* count,
enum transport_type transport, void (*sendfunc)(uint8_t*, size_t, void*),
void* userdata, FILE* verbose_out)
{
struct reply_packet *p;
uint8_t *outbuf = NULL;
size_t outlen = 0;
struct entry* entry = NULL;
verbose(1, "query %d: id %d: %s %d bytes: ", ++(*count),
(int)(inlen>=2?LDNS_ID_WIRE(inbuf):0),
(transport==transport_tcp)?"TCP":"UDP", (int)inlen);
if(verbose_out) {
char* out = sldns_wire2str_pkt(inbuf, (size_t)inlen);
printf("%s\n", out);
free(out);
}
/* fill up answer packet */
entry = find_match(entries, inbuf, (size_t)inlen, transport);
if(!entry || !entry->reply_list) {
verbose(1, "no answer packet for this query, no reply.\n");
return;
}
for(p = entry->reply_list; p; p = p->next)
{
verbose(3, "Answer pkt:\n");
if (p->reply_from_hex) {
/* try to adjust the hex packet, if it can be
* parsed, we can use adjust rules. if not,
* send packet literally */
/* still try to adjust ID if others fail */
outlen = sldns_buffer_limit(p->reply_from_hex);
outbuf = sldns_buffer_begin(p->reply_from_hex);
} else {
outbuf = p->reply_pkt;
outlen = p->reply_len;
}
if(!outbuf) {
verbose(1, "out of memory\n");
return;
}
/* copies outbuf in memory allocation */
adjust_packet(entry, &outbuf, &outlen, inbuf, (size_t)inlen);
verbose(1, "Answer packet size: %u bytes.\n", (unsigned int)outlen);
if(verbose_out) {
char* out = sldns_wire2str_pkt(outbuf, outlen);
printf("%s\n", out);
free(out);
}
if(p->packet_sleep) {
verbose(3, "sleeping for next packet %d secs\n",
p->packet_sleep);
#ifdef HAVE_SLEEP
sleep(p->packet_sleep);
#else
Sleep(p->packet_sleep * 1000);
#endif
verbose(3, "wakeup for next packet "
"(slept %d secs)\n", p->packet_sleep);
}
sendfunc(outbuf, outlen, userdata);
free(outbuf);
outbuf = NULL;
outlen = 0;
}
}
/** delete the list of reply packets */
void delete_replylist(struct reply_packet* replist)
{
struct reply_packet *p=replist, *np;
while(p) {
np = p->next;
free(p->reply_pkt);
sldns_buffer_free(p->reply_from_hex);
free(p);
p=np;
}
}
void delete_entry(struct entry* list)
{
struct entry *p=list, *np;
while(p) {
np = p->next;
delete_replylist(p->reply_list);
free(p);
p = np;
}
}
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