Merge pull request #888 from adamdunkels/pr/resolv-fixes

Resolv fixes, including CERT VU #210620
This commit is contained in:
Nicolas Tsiftes 2014-12-03 13:18:14 +01:00
commit ee7c847048

View file

@ -227,9 +227,6 @@ struct dns_hdr {
uint16_t numextrarr; uint16_t numextrarr;
}; };
#define RESOLV_ENCODE_INDEX(i) (uip_htons(i+1))
#define RESOLV_DECODE_INDEX(i) (unsigned char)(uip_ntohs(i-1))
/** These default values for the DNS server are Google's public DNS: /** These default values for the DNS server are Google's public DNS:
* <https://developers.google.com/speed/public-dns/docs/using> * <https://developers.google.com/speed/public-dns/docs/using>
*/ */
@ -264,6 +261,7 @@ struct namemap {
#define STATE_DONE 4 #define STATE_DONE 4
uint8_t state; uint8_t state;
uint8_t tmr; uint8_t tmr;
uint16_t id;
uint8_t retries; uint8_t retries;
uint8_t seqno; uint8_t seqno;
#if RESOLV_SUPPORTS_RECORD_EXPIRATION #if RESOLV_SUPPORTS_RECORD_EXPIRATION
@ -506,8 +504,6 @@ start_name_collision_check(clock_time_t after)
static unsigned char * static unsigned char *
mdns_write_announce_records(unsigned char *queryptr, uint8_t *count) mdns_write_announce_records(unsigned char *queryptr, uint8_t *count)
{ {
struct dns_answer *ans;
#if NETSTACK_CONF_WITH_IPV6 #if NETSTACK_CONF_WITH_IPV6
uint8_t i; uint8_t i;
@ -524,7 +520,6 @@ mdns_write_announce_records(unsigned char *queryptr, uint8_t *count)
*queryptr++ = 0xc0; *queryptr++ = 0xc0;
*queryptr++ = sizeof(struct dns_hdr); *queryptr++ = sizeof(struct dns_hdr);
} }
ans = (struct dns_answer *)queryptr;
*queryptr++ = (uint8_t) ((NATIVE_DNS_TYPE) >> 8); *queryptr++ = (uint8_t) ((NATIVE_DNS_TYPE) >> 8);
*queryptr++ = (uint8_t) ((NATIVE_DNS_TYPE)); *queryptr++ = (uint8_t) ((NATIVE_DNS_TYPE));
@ -546,6 +541,8 @@ mdns_write_announce_records(unsigned char *queryptr, uint8_t *count)
} }
} }
#else /* NETSTACK_CONF_WITH_IPV6 */ #else /* NETSTACK_CONF_WITH_IPV6 */
struct dns_answer *ans;
queryptr = encode_name(queryptr, resolv_hostname); queryptr = encode_name(queryptr, resolv_hostname);
ans = (struct dns_answer *)queryptr; ans = (struct dns_answer *)queryptr;
ans->type = UIP_HTONS(NATIVE_DNS_TYPE); ans->type = UIP_HTONS(NATIVE_DNS_TYPE);
@ -603,8 +600,6 @@ mdns_prep_host_announce_packet(void)
uint8_t total_answers = 0; uint8_t total_answers = 0;
struct dns_answer *ans;
/* Be aware that, unless `ARCH_DOESNT_NEED_ALIGNED_STRUCTS` is set, /* Be aware that, unless `ARCH_DOESNT_NEED_ALIGNED_STRUCTS` is set,
* writing directly to the uint16_t members of this struct is an error. */ * writing directly to the uint16_t members of this struct is an error. */
struct dns_hdr *hdr = (struct dns_hdr *)uip_appdata; struct dns_hdr *hdr = (struct dns_hdr *)uip_appdata;
@ -703,7 +698,8 @@ check_entries(void)
} }
hdr = (struct dns_hdr *)uip_appdata; hdr = (struct dns_hdr *)uip_appdata;
memset(hdr, 0, sizeof(struct dns_hdr)); memset(hdr, 0, sizeof(struct dns_hdr));
hdr->id = RESOLV_ENCODE_INDEX(i); hdr->id = random_rand();
namemapptr->id = hdr->id;
#if RESOLV_CONF_SUPPORTS_MDNS #if RESOLV_CONF_SUPPORTS_MDNS
if(!namemapptr->is_mdns || namemapptr->is_probe) { if(!namemapptr->is_mdns || namemapptr->is_probe) {
hdr->flags1 = DNS_FLAG1_RD; hdr->flags1 = DNS_FLAG1_RD;
@ -903,10 +899,13 @@ newdata(void)
} else } else
#endif /* RESOLV_CONF_SUPPORTS_MDNS */ #endif /* RESOLV_CONF_SUPPORTS_MDNS */
{ {
/* The ID in the DNS header should be our entry into the name table. */ for(i = 0; i < RESOLV_ENTRIES; ++i) {
i = RESOLV_DECODE_INDEX(hdr->id); namemapptr = &names[i];
if(namemapptr->state == STATE_ASKING &&
namemapptr = &names[i]; namemapptr->id == hdr->id) {
break;
}
}
if(i >= RESOLV_ENTRIES || i < 0 || namemapptr->state != STATE_ASKING) { if(i >= RESOLV_ENTRIES || i < 0 || namemapptr->state != STATE_ASKING) {
PRINTF("resolver: DNS response has bad ID (%04X) \n", uip_ntohs(hdr->id)); PRINTF("resolver: DNS response has bad ID (%04X) \n", uip_ntohs(hdr->id));
@ -1200,6 +1199,16 @@ PROCESS_THREAD(resolv_process, ev, data)
PROCESS_END(); PROCESS_END();
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static void
init(void)
{
static uint8_t initialized = 0;
if(!initialized) {
process_start(&resolv_process, NULL);
initialized = 1;
}
}
/*---------------------------------------------------------------------------*/
#if RESOLV_AUTO_REMOVE_TRAILING_DOTS #if RESOLV_AUTO_REMOVE_TRAILING_DOTS
static const char * static const char *
remove_trailing_dots(const char *name) { remove_trailing_dots(const char *name) {
@ -1233,6 +1242,8 @@ resolv_query(const char *name)
register struct namemap *nameptr = 0; register struct namemap *nameptr = 0;
init();
lseq = lseqi = 0; lseq = lseqi = 0;
/* Remove trailing dots, if present. */ /* Remove trailing dots, if present. */
@ -1369,7 +1380,8 @@ resolv_lookup(const char *name, uip_ipaddr_t ** ipaddr)
#if VERBOSE_DEBUG #if VERBOSE_DEBUG
switch (ret) { switch (ret) {
case RESOLV_STATUS_CACHED:{ case RESOLV_STATUS_CACHED:
if(ipaddr) {
PRINTF("resolver: Found \"%s\" in cache.\n", name); PRINTF("resolver: Found \"%s\" in cache.\n", name);
const uip_ipaddr_t *addr = *ipaddr; const uip_ipaddr_t *addr = *ipaddr;