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Commit 852adde1 authored by Vitezslav Kriz's avatar Vitezslav Kriz
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hints: reverse lookup keep name ordering from host file 

If one line contains multiple names for the address, the first
name should be the canonical one (i.e. used for reverse lookups).
In the current implementation wins top level domain according to
domain tree.

This change saves PTR records to separate tree. Names are
oredered according to order in host file.
parent a3306b09
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1 merge request!309hints: reverse lookup keep name ordering from host file
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with 142 additions and 89 deletions
modules/hints/hints.c
+ 142
− 89
View file @ 852adde1
......@@ -36,6 +36,11 @@
/* Defaults */
#define VERBOSE_MSG(qry, fmt...) QRVERBOSE(qry, "hint", fmt)
struct hints_data {
struct kr_zonecut hints;
struct kr_zonecut reverse_hints;
};
/** Useful for returning from module properties. */
static char * bool2jsonstr(bool val)
{
......@@ -77,37 +82,6 @@ static int put_answer(knot_pkt_t *pkt, knot_rrset_t *rr)
return ret;
}
static int find_reverse(const char *k, void *v, void *baton)
{
const knot_dname_t *domain = (const knot_dname_t *)k;
pack_t *addr_set = (pack_t *)v;
struct rev_search_baton *search = baton;
/* Check if it matches any of the addresses. */
bool matches = false;
uint8_t *addr = pack_head(*addr_set);
while (!matches && addr != pack_tail(*addr_set)) {
size_t len = pack_obj_len(addr);
void *addr_val = pack_obj_val(addr);
matches = (len == search->addr_len && memcmp(addr_val, (void *)&search->addr, len) == 0);
addr = pack_obj_next(addr);
}
/* Synthesise PTR record */
if (!matches) {
return 0;
}
knot_pkt_t *pkt = search->pkt;
knot_dname_t *qname = knot_dname_copy(search->name, &pkt->mm);
knot_rrset_t rr;
knot_rrset_init(&rr, qname, KNOT_RRTYPE_PTR, KNOT_CLASS_IN);
knot_rrset_add_rdata(&rr, domain, knot_dname_size(domain), 0, &pkt->mm);
/* Insert into packet */
int ret = put_answer(pkt, &rr);
if (ret == 0) {
return 1;
}
return ret;
}
static inline uint8_t label2num(const uint8_t **src, int base)
{
uint8_t ret = strtoul((const char *)(*src + 1), NULL, base) & 0xff; /* ord(0-64) => labels are separators */
......@@ -117,39 +91,24 @@ static inline uint8_t label2num(const uint8_t **src, int base)
static int satisfy_reverse(struct kr_zonecut *hints, knot_pkt_t *pkt, struct kr_query *qry)
{
struct rev_search_baton baton = {
.pkt = pkt,
.name = qry->sname,
.addr_len = sizeof(struct in_addr)
};
/* Check if it is IPv6/IPv4 query. */
size_t need_labels = baton.addr_len;
if (knot_dname_in((const uint8_t *)"\3ip6\4arpa", qry->sname)) {
baton.addr_len = sizeof(struct in6_addr);
need_labels = baton.addr_len * 2; /* Each label is a nibble */
}
/* Make address from QNAME (reverse order). */
int labels = knot_dname_labels(qry->sname, NULL);
if (labels != need_labels + 2) {
return kr_error(EINVAL);
}
const uint8_t *src = qry->sname;
uint8_t *dst = (uint8_t *)&baton.addr.ip4 + baton.addr_len - 1;
for (size_t i = 0; i < baton.addr_len; ++i) {
if (baton.addr_len == sizeof(struct in_addr)) { /* IPv4, 1 label = 1 octet */
*dst = label2num(&src, 10);
} else { /* IPv4, 1 label = 1 nibble */
*dst = label2num(&src, 16);
*dst |= label2num(&src, 16) << 4;
}
dst -= 1;
/* Find a matching name */
pack_t *addr_set = kr_zonecut_find(hints, qry->sname);
if (!addr_set || addr_set->len == 0) {
return kr_error(ENOENT);
}
/* Try to find matching domains. */
int ret = map_walk(&hints->nsset, find_reverse, &baton);
if (ret > 0) {
return kr_ok(); /* Found */
knot_dname_t *qname = knot_dname_copy(qry->sname, &pkt->mm);
knot_rrset_t rr;
knot_rrset_init(&rr, qname, KNOT_RRTYPE_PTR, KNOT_CLASS_IN);
/* Append address records from hints */
uint8_t *addr = pack_head(*addr_set);
if (addr != NULL) {
size_t len = pack_obj_len(addr);
void *addr_val = pack_obj_val(addr);
knot_rrset_add_rdata(&rr, addr_val, len, 0, &pkt->mm);
}
return kr_error(ENOENT);
return put_answer(pkt, &rr);
}
static int satisfy_forward(struct kr_zonecut *hints, knot_pkt_t *pkt, struct kr_query *qry)
......@@ -189,18 +148,18 @@ static int query(kr_layer_t *ctx, knot_pkt_t *pkt)
}
struct kr_module *module = ctx->api->data;
struct kr_zonecut *hint_map = module->data;
if (!hint_map) { /* No valid file. */
struct hints_data *data = module->data;
if (!data) { /* No valid file. */
return ctx->state;
}
switch(qry->stype) {
case KNOT_RRTYPE_A:
case KNOT_RRTYPE_AAAA: /* Find forward record hints */
if (satisfy_forward(hint_map, pkt, qry) != 0)
if (satisfy_forward(&data->hints, pkt, qry) != 0)
return ctx->state;
break;
case KNOT_RRTYPE_PTR: /* Find PTR record */
if (satisfy_reverse(hint_map, pkt, qry) != 0)
if (satisfy_reverse(&data->reverse_hints, pkt, qry) != 0)
return ctx->state;
break;
default:
......@@ -243,6 +202,53 @@ static const knot_rdata_t * addr2rdata(const char *addr) {
return rdata_arr;
}
/** @warning _NOT_ thread-safe; returns a pointer to static data! */
static const knot_dname_t * raw_addr2reverse(const uint8_t *raw_addr, int family)
{
char reverse_addr[KNOT_DNAME_MAXLEN];
static knot_dname_t dname[KNOT_DNAME_MAXLEN];
if (family == AF_INET) {
snprintf(reverse_addr, KNOT_DNAME_MAXLEN, "%d.%d.%d.%d.in-addr.arpa.",
raw_addr[3], raw_addr[2], raw_addr[1], raw_addr[0]
);
} else {
snprintf(reverse_addr, KNOT_DNAME_MAXLEN,
"%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.in-addr6.arpa.",
raw_addr[7] & 0x0f, (raw_addr[7] > 4),
raw_addr[6] & 0x0f, (raw_addr[6] > 4),
raw_addr[5] & 0x0f, (raw_addr[5] > 4),
raw_addr[4] & 0x0f, (raw_addr[4] > 4),
raw_addr[3] & 0x0f, (raw_addr[3] > 4),
raw_addr[2] & 0x0f, (raw_addr[2] > 4),
raw_addr[1] & 0x0f, (raw_addr[1] > 4),
raw_addr[0] & 0x0f, (raw_addr[0] > 4)
);
}
if (!knot_dname_from_str(dname, reverse_addr, sizeof(dname))) {
return NULL;
}
if (knot_dname_to_lower(dname) != KNOT_EOK) {
return NULL;
}
return dname;
}
/** @warning _NOT_ thread-safe; returns a pointer to static data! */
static const knot_dname_t * addr2reverse(const char *addr)
{
/* Parse address string */
struct sockaddr_storage ss;
if (parse_addr_str(&ss, addr) != 0) {
return NULL;
}
// Convert ip address to reverse order
const uint8_t *raw_addr = (const uint8_t *)kr_inaddr((struct sockaddr *)&ss);
int family = kr_inaddr_family((struct sockaddr *)&ss);
return raw_addr2reverse(raw_addr, family);
}
static int add_pair(struct kr_zonecut *hints, const char *name, const char *addr)
{
/* Build key */
......@@ -262,29 +268,71 @@ static int add_pair(struct kr_zonecut *hints, const char *name, const char *addr
return kr_zonecut_add(hints, key, rdata);
}
static int add_reverse_pair(struct kr_zonecut *hints, const char *name, const char *addr)
{
const knot_dname_t *key = addr2reverse(addr);
if (key == NULL) {
return kr_error(EINVAL);
}
knot_dname_t ptr_name[KNOT_DNAME_MAXLEN];
if (!knot_dname_from_str(ptr_name, name, sizeof(ptr_name))) {
return kr_error(EINVAL);
}
/* Build RDATA */
knot_rdata_t rdata[RDATA_ARR_MAX];
knot_rdata_init(rdata, knot_dname_size(ptr_name), ptr_name, 0);
return kr_zonecut_add(hints, key, rdata);
}
/** For a given name, remove either one address or all of them (if == NULL). */
static int del_pair(struct kr_zonecut *hints, const char *name, const char *addr)
static int del_pair(struct hints_data *data, const char *name, const char *addr)
{
/* Build key */
knot_dname_t key[KNOT_DNAME_MAXLEN];
if (!knot_dname_from_str(key, name, sizeof(key))) {
return kr_error(EINVAL);
}
knot_rdata_t ptr_rdata[RDATA_ARR_MAX];
knot_rdata_init(ptr_rdata, knot_dname_size(key), key, 0);
if (addr) {
/* Remove the pair. */
const knot_rdata_t *rdata = addr2rdata(addr);
if (!rdata) {
return kr_error(EINVAL);
}
return kr_zonecut_del(hints, key, rdata);
}
const knot_dname_t *reverse_key = addr2reverse(addr);
return kr_zonecut_del(&data->hints, key, rdata) |
kr_zonecut_del(&data->reverse_hints, reverse_key, ptr_rdata);
} else {
/* Find a matching name */
pack_t *addr_set = kr_zonecut_find(&data->hints, key);
if (!addr_set || addr_set->len == 0) {
return kr_error(ENOENT);
}
/* Append address records from hints */
uint8_t *addr = pack_head(*addr_set);
while (addr != pack_tail(*addr_set)) {
void *addr_val = pack_obj_val(addr);
int family = pack_obj_len(addr) == kr_family_len(AF_INET) ? AF_INET : AF_INET6;
const knot_dname_t *reverse_key = raw_addr2reverse(addr_val, family);
if (reverse_key != NULL) {
kr_zonecut_del(&data->reverse_hints, reverse_key, ptr_rdata);
}
addr = pack_obj_next(addr);
}
/* Remove the whole name. */
return kr_zonecut_del_all(hints, key);
return kr_zonecut_del_all(&data->hints, key);
}
}
static int load_map(struct kr_zonecut *hints, FILE *fp)
static int load_map(struct hints_data *data, FILE *fp)
{
size_t line_len = 0;
size_t count = 0;
......@@ -296,9 +344,10 @@ static int load_map(struct kr_zonecut *hints, FILE *fp)
if (tok == NULL || strchr(tok, '#') || strlen(tok) == 0) {
continue;
}
char *name_tok = strtok_r(NULL, " \t\n", &saveptr);
char *name_tok = strtok_r(NULL, " \t\n", &saveptr);
while (name_tok != NULL) {
if (add_pair(hints, name_tok, tok) == 0) {
add_reverse_pair(&data->reverse_hints, name_tok, tok);
if (add_pair(&data->hints, name_tok, tok) == 0) {
count += 1;
}
name_tok = strtok_r(NULL, " \t\n", &saveptr);
......@@ -320,8 +369,8 @@ static int load_file(struct kr_module *module, const char *path)
}
/* Load file to map */
struct kr_zonecut *hints = module->data;
return load_map(hints, fp);
struct hints_data *data = module->data;
return load_map(data, fp);
}
static char* hint_add_hosts(void *env, struct kr_module *module, const char *args)
......@@ -334,10 +383,11 @@ static char* hint_add_hosts(void *env, struct kr_module *module, const char *arg
static void unload(struct kr_module *module)
{
struct kr_zonecut *hints = module->data;
if (hints) {
kr_zonecut_deinit(hints);
mp_delete(hints->pool->ctx);
struct hints_data *data = module->data;
if (data) {
kr_zonecut_deinit(&data->hints);
kr_zonecut_deinit(&data->reverse_hints);
mp_delete(data->hints.pool->ctx);
module->data = NULL;
}
}
......@@ -351,7 +401,7 @@ static void unload(struct kr_module *module)
*/
static char* hint_set(void *env, struct kr_module *module, const char *args)
{
struct kr_zonecut *hints = module->data;
struct hints_data *data = module->data;
if (!args)
return NULL;
auto_free char *args_copy = strdup(args);
......@@ -362,7 +412,8 @@ static char* hint_set(void *env, struct kr_module *module, const char *args)
char *addr = strchr(args_copy, ' ');
if (addr) {
*addr = '\0';
ret = add_pair(hints, args_copy, addr + 1);
add_reverse_pair(&data->reverse_hints, args_copy, addr + 1);
ret = add_pair(&data->hints, args_copy, addr + 1);
}
return bool2jsonstr(ret == 0);
......@@ -370,7 +421,7 @@ static char* hint_set(void *env, struct kr_module *module, const char *args)
static char* hint_del(void *env, struct kr_module *module, const char *args)
{
struct kr_zonecut *hints = module->data;
struct hints_data *data = module->data;
if (!args)
return NULL;
auto_free char *args_copy = strdup(args);
......@@ -383,7 +434,7 @@ static char* hint_del(void *env, struct kr_module *module, const char *args)
*addr = '\0';
++addr;
}
ret = del_pair(hints, args_copy, addr);
ret = del_pair(data, args_copy, addr);
return bool2jsonstr(ret == 0);
}
......@@ -415,7 +466,7 @@ static char* pack_hints(struct kr_zonecut *hints);
*/
static char* hint_get(void *env, struct kr_module *module, const char *args)
{
struct kr_zonecut *hints = module->data;
struct kr_zonecut *hints = &((struct hints_data *) module->data)->hints;
if (!hints) {
assert(false);
return NULL;
......@@ -534,14 +585,16 @@ int hints_init(struct kr_module *module)
}
memcpy(pool, &_pool, sizeof(*pool));
struct kr_zonecut *hints = mm_alloc(pool, sizeof(*hints));
if (!hints) {
struct hints_data *data = mm_alloc(pool, sizeof(struct hints_data));
if (!data) {
mp_delete(pool->ctx);
return kr_error(ENOMEM);
}
hints->pool = pool;
kr_zonecut_init(hints, (const uint8_t *)(""), pool);
module->data = hints;
data->hints.pool = pool;
kr_zonecut_init(&data->hints, (const uint8_t *)(""), pool);
data->reverse_hints.pool = pool;
kr_zonecut_init(&data->reverse_hints, (const uint8_t *)(""), pool);
module->data = data;
return kr_ok();
}
......
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