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* dns.c: Hard-code structure sizes, to avoid issues on some compilers where

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padding is included.
This commit is contained in:
jifl 2008-10-02 13:53:16 +00:00
parent 0d7dccba5e
commit ba98bcdc60
2 changed files with 19 additions and 12 deletions
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4
CHANGELOG
View File

@ -47,6 +47,10 @@ HISTORY
++ Bugfixes:
2008-10-02 Jonathan Larmour
* dns.c: Hard-code structure sizes, to avoid issues on some compilers where
padding is included.
2008-09-30 Jonathan Larmour
* sockets.c (lwip_accept): check addr isn't NULL. If it's valid, do an
assertion check that addrlen isn't NULL.

27
src/core/dns.c
View File

@ -139,6 +139,7 @@ PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#define SIZEOF_DNS_HDR 12
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
@ -155,6 +156,7 @@ PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#define SIZEOF_DNS_QUERY 4
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
@ -173,6 +175,7 @@ PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#define SIZEOF_DNS_ANSWER 10
/** DNS table entry */
struct dns_table_entry {
@ -415,17 +418,17 @@ dns_send(u8_t numdns, const char* name, u8_t id)
LWIP_ASSERT("dns server has no IP address set", dns_servers[numdns].addr != 0);
/* if here, we have either a new query or a retry on a previous query to process */
p = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dns_hdr) + DNS_MAX_NAME_LENGTH +
sizeof(struct dns_query), PBUF_RAM);
p = pbuf_alloc(PBUF_TRANSPORT, SIZEOF_DNS_HDR + DNS_MAX_NAME_LENGTH +
SIZEOF_DNS_QUERY, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
/* fill dns header */
hdr = (struct dns_hdr*)p->payload;
memset(hdr, 0, sizeof(struct dns_hdr));
memset(hdr, 0, SIZEOF_DNS_HDR);
hdr->id = htons(id);
hdr->flags1 = DNS_FLAG1_RD;
hdr->numquestions = htons(1);
query = (char*)hdr + sizeof(struct dns_hdr);
query = (char*)hdr + SIZEOF_DNS_HDR;
pHostname = name;
--pHostname;
@ -446,10 +449,10 @@ dns_send(u8_t numdns, const char* name, u8_t id)
/* fill dns query */
qry.type = htons(DNS_RRTYPE_A);
qry.class = htons(DNS_RRCLASS_IN);
MEMCPY( query, &qry, sizeof(struct dns_query));
MEMCPY( query, &qry, SIZEOF_DNS_QUERY);
/* resize pbuf to the exact dns query */
pbuf_realloc(p, (query + sizeof(struct dns_query)) - ((char*)(p->payload)));
pbuf_realloc(p, (query + SIZEOF_DNS_QUERY) - ((char*)(p->payload)));
/* connect to the server for faster receiving */
udp_connect(dns_pcb, &dns_servers[numdns], DNS_SERVER_PORT);
@ -591,7 +594,7 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u
}
/* is the dns message big enough ? */
if (p->tot_len < (sizeof(struct dns_hdr) + sizeof(struct dns_query) + sizeof(struct dns_answer))) {
if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
/* free pbuf and return */
goto memerr1;
@ -632,7 +635,7 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u
#if DNS_DOES_NAME_CHECK
/* Check if the name in the "question" part match with the name in the entry. */
if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + sizeof(struct dns_hdr)) != 0) {
if (dns_compare_name((unsigned char *)(pEntry->name), (unsigned char *)dns_payload + SIZEOF_DNS_HDR) != 0) {
LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response not match to query\n", pEntry->name));
/* call callback to indicate error, clean up memory and return */
goto responseerr;
@ -640,14 +643,14 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u
#endif /* DNS_DOES_NAME_CHECK */
/* Skip the name in the "question" part */
pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + sizeof(struct dns_hdr)) + sizeof(struct dns_query);
pHostname = (char *) dns_parse_name((unsigned char *)dns_payload + SIZEOF_DNS_HDR) + SIZEOF_DNS_QUERY;
while(nanswers > 0) {
/* skip answer resource record's host name */
pHostname = (char *) dns_parse_name((unsigned char *)pHostname);
/* Check for IP address type and Internet class. Others are discarded. */
MEMCPY(&ans, pHostname, sizeof(struct dns_answer));
MEMCPY(&ans, pHostname, SIZEOF_DNS_ANSWER);
if((ntohs(ans.type) == DNS_RRTYPE_A) && (ntohs(ans.class) == DNS_RRCLASS_IN) && (ntohs(ans.len) == sizeof(struct ip_addr)) ) {
/* read the answer resource record's TTL, and maximize it if needed */
pEntry->ttl = ntohl(ans.ttl);
@ -655,7 +658,7 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u
pEntry->ttl = DNS_MAX_TTL;
}
/* read the IP address after answer resource record's header */
MEMCPY( &(pEntry->ipaddr), (pHostname+sizeof(struct dns_answer)), sizeof(struct ip_addr));
MEMCPY( &(pEntry->ipaddr), (pHostname+SIZEOF_DNS_ANSWER), sizeof(struct ip_addr));
LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: \"%s\": response = ", pEntry->name));
ip_addr_debug_print(DNS_DEBUG, (&(pEntry->ipaddr)));
LWIP_DEBUGF(DNS_DEBUG, ("\n"));
@ -666,7 +669,7 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u
/* deallocate memory and return */
goto memerr2;
} else {
pHostname = pHostname + sizeof(struct dns_answer) + htons(ans.len);
pHostname = pHostname + SIZEOF_DNS_ANSWER + htons(ans.len);
}
--nanswers;
}