patch from richard

sort multiple DNS records using a key
This commit is contained in:
Alfred E. Heggestad 2016-06-21 14:58:15 +00:00
parent 64d5123da7
commit 107323352d
4 changed files with 79 additions and 22 deletions

View file

@ -172,7 +172,8 @@ int dns_dname_encode(struct mbuf *mb, const char *name,
int dns_dname_decode(struct mbuf *mb, char **name, size_t start); int dns_dname_decode(struct mbuf *mb, char **name, size_t start);
int dns_cstr_encode(struct mbuf *mb, const char *str); int dns_cstr_encode(struct mbuf *mb, const char *str);
int dns_cstr_decode(struct mbuf *mb, char **str); int dns_cstr_decode(struct mbuf *mb, char **str);
void dns_rrlist_sort(struct list *rrl, uint16_t type); void dns_rrlist_sort(struct list *rrl, uint16_t type, size_t key);
void dns_rrlist_sort_addr(struct list *rrl, size_t key);
struct dnsrr *dns_rrlist_apply(struct list *rrl, const char *name, struct dnsrr *dns_rrlist_apply(struct list *rrl, const char *name,
uint16_t type, uint16_t dnsclass, uint16_t type, uint16_t dnsclass,
bool recurse, dns_rrlist_h *rrlh, void *arg); bool recurse, dns_rrlist_h *rrlh, void *arg);

View file

@ -3,8 +3,10 @@
* *
* Copyright (C) 2010 Creytiv.com * Copyright (C) 2010 Creytiv.com
*/ */
#include <string.h>
#include <re_types.h> #include <re_types.h>
#include <re_list.h> #include <re_list.h>
#include <re_hash.h>
#include <re_mbuf.h> #include <re_mbuf.h>
#include <re_fmt.h> #include <re_fmt.h>
#include <re_dns.h> #include <re_dns.h>
@ -15,31 +17,56 @@ enum {
}; };
struct sort {
uint16_t type;
uint32_t key;
};
static uint32_t sidx(const struct dnsrr *rr, uint32_t key)
{
uint32_t addr[4];
switch (rr->type) {
case DNS_TYPE_A:
return rr->rdata.a.addr ^ key;
case DNS_TYPE_AAAA:
memcpy(addr, rr->rdata.aaaa.addr, 16);
return addr[0] ^ addr[1] ^ addr[2] ^ addr[3] ^ key;
case DNS_TYPE_SRV:
return ((hash_fast_str(rr->rdata.srv.target) & 0xfff) ^ key) +
rr->rdata.srv.weight;
default:
return 0;
}
}
static bool std_sort_handler(struct le *le1, struct le *le2, void *arg) static bool std_sort_handler(struct le *le1, struct le *le2, void *arg)
{ {
struct dnsrr *rr1 = le1->data; struct dnsrr *rr1 = le1->data;
struct dnsrr *rr2 = le2->data; struct dnsrr *rr2 = le2->data;
const uint16_t type = *(uint16_t *)arg; struct sort *sort = arg;
if (type != rr1->type) if (sort->type != rr1->type)
return type != rr2->type; return sort->type != rr2->type;
if (type != rr2->type) if (sort->type != rr2->type)
return true; return true;
switch (type) { switch (sort->type) {
case DNS_TYPE_MX: case DNS_TYPE_MX:
return rr1->rdata.mx.pref <= rr2->rdata.mx.pref; return rr1->rdata.mx.pref <= rr2->rdata.mx.pref;
case DNS_TYPE_SRV: case DNS_TYPE_SRV:
if (rr1->rdata.srv.pri == rr2->rdata.srv.pri) { if (rr1->rdata.srv.pri == rr2->rdata.srv.pri)
return sidx(rr1, sort->key) >= sidx(rr2, sort->key);
if (rr1->rdata.srv.weight)
return 0 != rr2->rdata.srv.weight;
return true;
}
return rr1->rdata.srv.pri < rr2->rdata.srv.pri; return rr1->rdata.srv.pri < rr2->rdata.srv.pri;
@ -57,16 +84,42 @@ static bool std_sort_handler(struct le *le1, struct le *le2, void *arg)
} }
static bool addr_sort_handler(struct le *le1, struct le *le2, void *arg)
{
struct dnsrr *rr1 = le1->data;
struct dnsrr *rr2 = le2->data;
struct sort *sort = arg;
return sidx(rr1, sort->key) >= sidx(rr2, sort->key);
}
/** /**
* Sort a list of DNS Resource Records * Sort a list of DNS Resource Records
* *
* @param rrl DNS Resource Record list * @param rrl DNS Resource Record list
* @param type DNS Record type * @param type DNS Record type
* @param key Sort key
*/ */
void dns_rrlist_sort(struct list *rrl, uint16_t type) void dns_rrlist_sort(struct list *rrl, uint16_t type, size_t key)
{ {
list_sort(rrl, std_sort_handler, &type); struct sort sort = {type, (uint32_t)key>>5};
/* todo add SRV postprocessing for weighted load balancing. */
list_sort(rrl, std_sort_handler, &sort);
}
/**
* Sort a list of A/AAAA DNS Resource Records
*
* @param rrl DNS Resource Record list
* @param key Sort key
*/
void dns_rrlist_sort_addr(struct list *rrl, size_t key)
{
struct sort sort = {0, (uint32_t)key>>5};
list_sort(rrl, addr_sort_handler, &sort);
} }

View file

@ -227,6 +227,7 @@ static int request_next(struct sip_request *req)
list_unlink(&rr->le); list_unlink(&rr->le);
if (req->addrl.head) { if (req->addrl.head) {
dns_rrlist_sort_addr(&req->addrl, (size_t)req->arg);
mem_deref(rr); mem_deref(rr);
goto again; goto again;
} }
@ -392,7 +393,7 @@ static void naptr_handler(int err, const struct dnshdr *hdr, struct list *ansl,
(void)hdr; (void)hdr;
(void)authl; (void)authl;
dns_rrlist_sort(ansl, DNS_TYPE_NAPTR); dns_rrlist_sort(ansl, DNS_TYPE_NAPTR, (size_t)req->arg);
rr = dns_rrlist_apply(ansl, NULL, DNS_TYPE_NAPTR, DNS_CLASS_IN, false, rr = dns_rrlist_apply(ansl, NULL, DNS_TYPE_NAPTR, DNS_CLASS_IN, false,
rr_naptr_handler, req); rr_naptr_handler, req);
@ -410,8 +411,6 @@ static void naptr_handler(int err, const struct dnshdr *hdr, struct list *ansl,
return; return;
} }
dns_rrlist_sort(addl, DNS_TYPE_SRV);
dns_rrlist_apply(addl, rr->rdata.naptr.replace, DNS_TYPE_SRV, dns_rrlist_apply(addl, rr->rdata.naptr.replace, DNS_TYPE_SRV,
DNS_CLASS_IN, true, rr_append_handler, &req->srvl); DNS_CLASS_IN, true, rr_append_handler, &req->srvl);
@ -425,6 +424,8 @@ static void naptr_handler(int err, const struct dnshdr *hdr, struct list *ansl,
return; return;
} }
dns_rrlist_sort(&req->srvl, DNS_TYPE_SRV, (size_t)req->arg);
dns_rrlist_apply(addl, NULL, DNS_QTYPE_ANY, DNS_CLASS_IN, false, dns_rrlist_apply(addl, NULL, DNS_QTYPE_ANY, DNS_CLASS_IN, false,
rr_cache_handler, req); rr_cache_handler, req);
@ -447,8 +448,6 @@ static void srv_handler(int err, const struct dnshdr *hdr, struct list *ansl,
(void)hdr; (void)hdr;
(void)authl; (void)authl;
dns_rrlist_sort(ansl, DNS_TYPE_SRV);
dns_rrlist_apply(ansl, NULL, DNS_TYPE_SRV, DNS_CLASS_IN, false, dns_rrlist_apply(ansl, NULL, DNS_TYPE_SRV, DNS_CLASS_IN, false,
rr_append_handler, &req->srvl); rr_append_handler, &req->srvl);
@ -479,6 +478,8 @@ static void srv_handler(int err, const struct dnshdr *hdr, struct list *ansl,
return; return;
} }
dns_rrlist_sort(&req->srvl, DNS_TYPE_SRV, (size_t)req->arg);
dns_rrlist_apply(addl, NULL, DNS_QTYPE_ANY, DNS_CLASS_IN, false, dns_rrlist_apply(addl, NULL, DNS_QTYPE_ANY, DNS_CLASS_IN, false,
rr_cache_handler, req); rr_cache_handler, req);
@ -514,6 +515,8 @@ static void addr_handler(int err, const struct dnshdr *hdr, struct list *ansl,
goto fail; goto fail;
} }
dns_rrlist_sort_addr(&req->addrl, (size_t)req->arg);
err = request_next(req); err = request_next(req);
if (err) if (err)
goto fail; goto fail;

View file

@ -138,7 +138,7 @@ static void srv_handler(int err, const struct dnshdr *hdr, struct list *ansl,
(void)hdr; (void)hdr;
(void)authl; (void)authl;
dns_rrlist_sort(ansl, DNS_TYPE_SRV); dns_rrlist_sort(ansl, DNS_TYPE_SRV, (size_t)dns->arg);
/* Find SRV answers */ /* Find SRV answers */
rr = dns_rrlist_find(ansl, NULL, DNS_TYPE_SRV, DNS_CLASS_IN, false); rr = dns_rrlist_find(ansl, NULL, DNS_TYPE_SRV, DNS_CLASS_IN, false);