Skip to content

Commit

Permalink
filter refactoring
Browse files Browse the repository at this point in the history
  • Loading branch information
@tschiemer
tschiemer committed Jul 5, 2020
1 parent d3f3203 commit 2eb62ca
Show file tree
Hide file tree
Showing 4 changed files with 242 additions and 66 deletions.
127 changes: 93 additions & 34 deletions minimr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@
#include "minimr.h"


const uint8_t * minimr_dns_type_str(uint16_t type)
const uint8_t * minimr_dns_type_tostr(uint16_t type)
{
switch (type) {
case MINIMR_DNS_TYPE_ANY: return (uint8_t*)"ANY";
Expand All @@ -19,24 +19,48 @@ const uint8_t * minimr_dns_type_str(uint16_t type)
return (uint8_t*)"?";
}

const uint8_t * minimr_dns_class_tostr(uint16_t glass)
{
switch (glass) {
case MINIMR_DNS_CLASS_ANY: return (uint8_t*)"ANY";
case MINIMR_DNS_CLASS_IN: return (uint8_t*)"IN";

}
return (uint8_t*)"?";
}

#define _seq1_(lhs, rhs) ( lhs[0] == rhs[0] )
#define _seq2_(lhs, rhs) ( lhs[0] == rhs[0] )
#define _seq3_(lhs, rhs) ( lhs[0] == rhs[0] )
#define _seq4_(lhs, rhs) ( lhs[0] == rhs[0] )
#define _seq2_(lhs, rhs) ( lhs[0] == rhs[0] && lhs[1] == rhs[1] )
#define _seq3_(lhs, rhs) ( lhs[0] == rhs[0] && lhs[1] == rhs[1] && lhs[2] == rhs[2] )
#define _seq4_(lhs, rhs) ( lhs[0] == rhs[0] && lhs[1] == rhs[1] && lhs[2] == rhs[2] && lhs[3] == rhs[4])

uint16_t minimr_dns_type_fromstr(uint8_t * typestr)
{
if (_seq3_(typestr, "ANY")) return MINIMR_DNS_TYPE_ANY;
if (_seq1_(typestr, "A")) return MINIMR_DNS_TYPE_A;
// in decreasing order of length

if (_seq4_(typestr, "AAAA")) return MINIMR_DNS_TYPE_AAAA;

if (_seq3_(typestr, "ANY")) return MINIMR_DNS_TYPE_ANY;
if (_seq3_(typestr, "SRV")) return MINIMR_DNS_TYPE_SRV;
if (_seq3_(typestr, "TXT")) return MINIMR_DNS_TYPE_TXT;
if (_seq3_(typestr, "PTR")) return MINIMR_DNS_TYPE_PTR;

if (_seq1_(typestr, "A")) return MINIMR_DNS_TYPE_A;

MINIMR_DEBUGF("type not recognized! %s\n", typestr);

return 0;
}


uint16_t minimr_dns_class_fromstr(uint8_t * classstr)
{
// in decreasing order of length
if (_seq3_(classstr, "ANY")) return MINIMR_DNS_CLASS_ANY;
if (_seq2_(classstr, "IN")) return MINIMR_DNS_CLASS_IN;

MINIMR_DEBUGF("class not recognized! %s\n", classstr);

return 0;
}

Expand Down Expand Up @@ -213,6 +237,13 @@ void minimr_dns_normalize_field(uint8_t * field, uint16_t * length, uint8_t mark
{
MINIMR_ASSERT(field != NULL);

// if first byte does not match marker, we assume the field has already been normalized
// note: this could the source of an error where the field to be normalized in fact was just wrongly formatted..
if (field[0] != marker){
MINIMR_DEBUGF("WARNING first byte of field to be normalized is not marker '%c' - assumed to be normalized alread\n", marker);
return;
}

uint16_t i = 0;

while(field[i] != '\0'){
Expand Down Expand Up @@ -247,10 +278,10 @@ void minimr_dns_denormalize_field(uint8_t * field, uint16_t length, uint8_t mark
}
}

uint8_t minimr_dns_name_len(uint16_t namepos, uint8_t * msg, uint16_t msglen, uint8_t * namelen, uint8_t * bytelen)
{
return MINIMR_OK;
}
//uint8_t minimr_dns_name_len(uint16_t namepos, uint8_t * msg, uint16_t msglen, uint8_t * namelen, uint8_t * bytelen)
//{
// return MINIMR_OK;
//}


int32_t minimr_dns_name_cmp(uint8_t * uncompressed_name, uint16_t namepos, uint8_t * msg, uint16_t msglen)
Expand Down Expand Up @@ -405,16 +436,16 @@ int32_t minimr_dns_uncompress_name(uint8_t * uncompressed_name, uint16_t maxlen,
}


uint8_t minimr_parse_msg(
int32_t minimr_parse_msg(
uint8_t *msg, uint16_t msglen,
minimr_query_handler qhandler, uint8_t **qfilter_names, uint16_t nqfilter_names,
minimr_rr_handler rrhandler, uint8_t **rrfilter_names, uint16_t nrrfilter_names,
minimr_query_handler qhandler, struct minimr_filter * qfilters, uint16_t nqfilters,
minimr_rr_handler rrhandler, struct minimr_filter * rrfilters, uint16_t nrrfilters,
void * user_data
)
{
MINIMR_ASSERT(msg != NULL);
MINIMR_ASSERT(nqfilter_names == 0 || qfilter_names != NULL);
MINIMR_ASSERT(nrrfilter_names == 0 || rrfilter_names != NULL);
MINIMR_ASSERT(nqfilters == 0 || qfilters != NULL);
MINIMR_ASSERT(nrrfilters == 0 || rrfilters != NULL);
MINIMR_ASSERT(qhandler != NULL && rrhandler != NULL); // doesn't make any sense not to use any handler at all.

MINIMR_DEBUGF("\nnew msg %p (len %d)\n", msg, msglen);
Expand Down Expand Up @@ -454,17 +485,33 @@ uint8_t minimr_parse_msg(
continue;
}


uint8_t cont = MINIMR_CONTINUE;

if (nqfilter_names == 0){
cont = qhandler(&hdr, &qstat, msg, msglen, 0, user_data);
if (nqfilters == 0){
cont = qhandler(&hdr, &qstat, msg, msglen, user_data);
} else {

for (uint16_t i = 0; i < nqfilter_names; i++){
for (uint16_t i = 0; i < nqfilters; i++){

MINIMR_ASSERT(qfilters[i].name != NULL);

// type match?
if (qfilters[i].type != MINIMR_DNS_TYPE_ANY && qstat.type != MINIMR_DNS_TYPE_ANY && qfilters[i].type != qstat.type){
continue;
}

// class match?
if (qfilters[i].fclass != MINIMR_DNS_CLASS_ANY && (qstat.unicast_class & MINIMR_DNS_QCLASS) != MINIMR_DNS_CLASS_ANY && qfilters[i].fclass != (qstat.unicast_class & MINIMR_DNS_QCLASS) ){
continue;
}

if (minimr_dns_name_cmp(qfilters[i].name, qstat.name_offset, msg, msglen) == 0){

qstat.match_i = i;

if (minimr_dns_name_cmp(qfilter_names[i], qstat.name_offset, msg, msglen) == 0){
// pass to user rr handler
cont = qhandler(&hdr, &qstat, msg, msglen, i, user_data);
cont = qhandler(&hdr, &qstat, msg, msglen, user_data);
}
}
}
Expand Down Expand Up @@ -503,13 +550,11 @@ uint8_t minimr_parse_msg(

// in case of a server fail, pass this along
if (res == MINIMR_DNS_HDR2_RCODE_SERVAIL) {
MINIMR_DEBUGF("1\n");
return MINIMR_DNS_HDR2_RCODE_SERVAIL;
}

if (res != MINIMR_OK){
// we could respond that it was a faulty query..
MINIMR_DEBUGF("2\n");
return MINIMR_DNS_HDR2_RCODE_FORMERR;
}

Expand All @@ -524,14 +569,28 @@ uint8_t minimr_parse_msg(
uint8_t cont = MINIMR_CONTINUE;

// if any filter records were given, just look for these
if (nrrfilter_names == 0) {
cont = rrhandler(&hdr, section, &rstat, msg, msglen, 0, user_data);
if (nrrfilters == 0) {
cont = rrhandler(&hdr, section, &rstat, msg, msglen, user_data);
} else {
for (uint16_t i = 0; i < nrrfilter_names; i++){
for (uint16_t i = 0; i < nrrfilters; i++){

MINIMR_ASSERT(rrfilters[i].name != NULL);

// type match?
if (rrfilters[i].type != MINIMR_DNS_TYPE_ANY && rrfilters[i].type != rstat.type){
continue;
}
// class match?
if (rrfilters[i].fclass != MINIMR_DNS_CLASS_ANY && rrfilters[i].fclass != (rstat.cache_class & MINIMR_DNS_RRCLASS) ){
continue;
}

if (minimr_dns_name_cmp(rrfilters[i].name, rstat.name_offset, msg, msglen) == 0){

rstat.match_i = i;

if (minimr_dns_name_cmp(rrfilter_names[i], rstat.name_offset, msg, msglen) == 0){
// pass to user rr handler
cont = rrhandler(&hdr, section, &rstat, msg, msglen, i, user_data);
cont = rrhandler(&hdr, section, &rstat, msg, msglen, user_data);
}
}
}
Expand All @@ -545,7 +604,7 @@ uint8_t minimr_parse_msg(
return MINIMR_OK;
}

uint8_t minimr_make_msg(
int32_t minimr_make_msg(
uint16_t tid, uint8_t flag1, uint8_t flag2,
struct minimr_dns_rr **records, uint16_t nrecords,
uint8_t *outmsg, uint16_t *outmsglen, uint16_t outmsgmaxlen,
Expand Down Expand Up @@ -846,7 +905,7 @@ uint8_t minimr_handle_queries(
// but let's remember this question and the matching record and let's go to the next question

qstats[nq].relevant = 1;
qstats[nq].ir = ir;
qstats[nq].match_i = ir;

nq++;

Expand Down Expand Up @@ -908,13 +967,13 @@ uint8_t minimr_handle_queries(


// if name lengths don't match, there's no point checking names
res = minimr_dns_name_cmp(records[qstats[iq].ir]->name, qstats[iq].name_offset, msg, msglen);
res = minimr_dns_name_cmp(records[qstats[iq].match_i]->name, qstats[iq].name_offset, msg, msglen);

if (res != 0) continue;
}

// so it's a match and we have to check wether it's up to date
struct minimr_dns_rr * rr = records[qstats[iq].ir];
struct minimr_dns_rr * rr = records[qstats[iq].match_i];
if (rr->fun(minimr_dns_rr_fun_type_respond_to, rr, &rstat, msg) == MINIMR_DO_NOT_RESPOND){
qstats[iq].relevant = 0;
remaining_nq--;
Expand Down Expand Up @@ -966,7 +1025,7 @@ uint8_t minimr_handle_queries(
continue;
}

struct minimr_dns_rr * rr = records[qstats[iq].ir];
struct minimr_dns_rr * rr = records[qstats[iq].match_i];

uint16_t nrr = 0;

Expand All @@ -990,7 +1049,7 @@ uint8_t minimr_handle_queries(
continue;
}

struct minimr_dns_rr * rr = records[qstats[iq].ir];
struct minimr_dns_rr * rr = records[qstats[iq].match_i];

uint16_t nrr = 0;

Expand All @@ -1014,7 +1073,7 @@ uint8_t minimr_handle_queries(
continue;
}

struct minimr_dns_rr * rr = records[qstats[iq].ir];
struct minimr_dns_rr * rr = records[qstats[iq].match_i];

uint16_t nrr = 0;

Expand Down
34 changes: 23 additions & 11 deletions minimr.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
#ifndef MINIMR_MINIMR_H
#define MINIMR_MINIMR_H

#include "examples/minimropt.h"
#include "minimropt.h"

#ifdef __cplusplus
extern "C" {
Expand Down Expand Up @@ -146,8 +146,10 @@ extern "C" {
#define MINIMR_DNS_TYPE_URI 256
#define MINIMR_DNS_TYPE_ZONEMD 63

const uint8_t * minimr_dns_type_str(uint16_t type);
const uint8_t * minimr_dns_type_tostr(uint16_t type);
uint16_t minimr_dns_type_fromstr(uint8_t * typestr);
const uint8_t * minimr_dns_class_tostr(uint16_t glass);
uint16_t minimr_dns_class_fromstr(uint8_t * classstr);

// Marker of compressed name
#define MINIMR_DNS_COMPRESSED_NAME 0xc0
Expand Down Expand Up @@ -302,7 +304,7 @@ struct minimr_dns_query_stat {
uint16_t name_offset; // offset of name w.r.t message base

// internal usage
uint16_t ir; // record index of matched record (used in processing to avoid reprocessing)
uint16_t match_i; // record index of matched record (used in processing to avoid reprocessing)
uint8_t relevant; //
};

Expand Down Expand Up @@ -354,6 +356,8 @@ struct minimr_dns_rr_stat {
uint16_t name_offset;

uint16_t data_offset;

uint8_t match_i; // record index (of matched record or filter)
};

/**
Expand Down Expand Up @@ -625,7 +629,7 @@ typedef MINIMR_DNS_RR_TYPE_A(MINIMR_DNS_RR_TYPE_A_DEFAULT_NAMELEN) minimr_dns_rr



/*************** NAME utilities **************/
/*************** NAME and general field utilities **************/


/**
Expand All @@ -651,7 +655,7 @@ void minimr_dns_normalize_field(uint8_t * field, uint16_t * length, uint8_t mark
*/
void minimr_dns_denormalize_field(uint8_t * field, uint16_t length, uint8_t marker);

uint8_t minimr_dns_name_len(uint16_t namepos, uint8_t * msg, uint16_t msglen, uint8_t * namelen, uint8_t * bytelen);
//uint8_t minimr_dns_name_len(uint16_t namepos, uint8_t * msg, uint16_t msglen, uint8_t * namelen, uint8_t * bytelen);

/**
* Lexicographic comparison of two NAMEs where the first MUST be uncompressed and the second CAN be compressed with given message bounds
Expand All @@ -674,8 +678,16 @@ typedef enum {
minimr_dns_rr_section_extra
} minimr_dns_rr_section;

typedef uint8_t (*minimr_query_handler)(struct minimr_dns_hdr * hdr, struct minimr_dns_query_stat * qstat, uint8_t * msg, uint16_t msglen, uint8_t ifilter, void * user_data);
typedef uint8_t (*minimr_rr_handler)(struct minimr_dns_hdr * hdr, minimr_dns_rr_section, struct minimr_dns_rr_stat * rstat, uint8_t * msg, uint16_t msglen, uint8_t ifilter, void * user_data);
struct minimr_filter {
uint16_t type;
uint16_t fclass;
uint8_t * name;
uint16_t name_length;

};

typedef uint8_t (*minimr_query_handler)(struct minimr_dns_hdr * hdr, struct minimr_dns_query_stat * qstat, uint8_t * msg, uint16_t msglen, void * user_data);
typedef uint8_t (*minimr_rr_handler)(struct minimr_dns_hdr * hdr, minimr_dns_rr_section, struct minimr_dns_rr_stat * rstat, uint8_t * msg, uint16_t msglen, void * user_data);

/**
* Tries to parse given mDNS message calling the (optional) handlers for each encountered query or RR
Expand All @@ -684,14 +696,14 @@ typedef uint8_t (*minimr_rr_handler)(struct minimr_dns_hdr * hdr, minimr_dns_rr_
* @see minimr_query_handler
* @see minimr_rr_handler
*/
uint8_t minimr_parse_msg(
int32_t minimr_parse_msg(
uint8_t *msg, uint16_t msglen,
minimr_query_handler qhandler, uint8_t **qfilter_names, uint16_t nqfilter_names,
minimr_rr_handler rrhandler, uint8_t **rrfilter_names, uint16_t nrrfilter_names,
minimr_query_handler qhandler, struct minimr_filter * qfilters, uint16_t nqfilters,
minimr_rr_handler rrhandler, struct minimr_filter * rrfilters, uint16_t nrrfilters,
void * user_data
);

uint8_t minimr_make_msg(
int32_t minimr_make_msg(
uint16_t tid, uint8_t flag1, uint8_t flag2,
struct minimr_dns_rr **records, uint16_t nrecords,
uint8_t *outmsg, uint16_t *outmsglen, uint16_t outmsgmaxlen,
Expand Down
2 changes: 1 addition & 1 deletion utils/reader/minimropt.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@
#define MINIMR_ASSERT(x) assert(x)

// optional
#define MINIMR_DEBUGF(...) fprintf(stderr, __VA_ARGS__)
//#define MINIMR_DEBUGF(...) fprintf(stderr, __VA_ARGS__)


#endif //MINIMR_MINIMROPT_H
Loading

0 comments on commit 2eb62ca

Please sign in to comment.