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authorRich Felker <dalias@aerifal.cx>2014-06-01 00:09:28 -0400
committerRich Felker <dalias@aerifal.cx>2014-06-01 00:09:28 -0400
commite8f39ca4898237cf71657500f0b11534c47a0521 (patch)
tree3c528e1c46e834d8581079f1ddc6198dde7ce0e7
parent6f409bff008a83fa6bc640c10366765874de35e2 (diff)
downloadmusl-e8f39ca4898237cf71657500f0b11534c47a0521.tar.gz
improve gethostbyname2_r using new resolver backend
these changes reduce the size of the function somewhat and remove many of its dependencies, including free. in principle it should now be async-signal-safe, but this has not been verified in detail. minor changes to error handling are also made.
-rw-r--r--src/network/gethostbyname2_r.c57
1 files changed, 22 insertions, 35 deletions
diff --git a/src/network/gethostbyname2_r.c b/src/network/gethostbyname2_r.c
index 27eb080f..aa8b0a9e 100644
--- a/src/network/gethostbyname2_r.c
+++ b/src/network/gethostbyname2_r.c
@@ -6,41 +6,31 @@
#include <netinet/in.h>
#include <errno.h>
#include <stdint.h>
+#include "lookup.h"
int gethostbyname2_r(const char *name, int af,
struct hostent *h, char *buf, size_t buflen,
struct hostent **res, int *err)
{
- struct addrinfo hint = {
- .ai_family = af==AF_INET6 ? af : AF_INET,
- .ai_flags = AI_CANONNAME
- };
- struct addrinfo *ai, *p;
- int i;
- size_t need;
- const char *canon;
+ struct address addrs[MAXADDRS];
+ char canon[256];
+ int i, cnt;
+ size_t align, need;
- af = hint.ai_family;
-
- /* Align buffer */
- i = (uintptr_t)buf & sizeof(char *)-1;
- if (i) {
- if (buflen < sizeof(char *)-i) return ERANGE;
- buf += sizeof(char *)-i;
- buflen -= sizeof(char *)-i;
- }
-
- switch (getaddrinfo(name, 0, &hint, &ai)) {
+ cnt = __lookup_name(addrs, canon, name, af, AI_CANONNAME);
+ if (cnt<0) switch (cnt) {
case EAI_NONAME:
*err = HOST_NOT_FOUND;
- return errno;
+ return ENOENT;
case EAI_AGAIN:
*err = TRY_AGAIN;
- return errno;
+ return EAGAIN;
default:
+ case EAI_FAIL:
+ *err = NO_RECOVERY;
+ return EBADMSG;
case EAI_MEMORY:
case EAI_SYSTEM:
- case EAI_FAIL:
*err = NO_RECOVERY;
return errno;
case 0:
@@ -50,22 +40,22 @@ int gethostbyname2_r(const char *name, int af,
h->h_addrtype = af;
h->h_length = af==AF_INET6 ? 16 : 4;
- canon = ai->ai_canonname ? ai->ai_canonname : name;
+ /* Align buffer */
+ align = -(uintptr_t)buf & sizeof(char *)-1;
+
need = 4*sizeof(char *);
- for (i=0, p=ai; p; i++, p=p->ai_next)
- need += sizeof(char *) + h->h_length;
+ need += (cnt + 1) * (sizeof(char *) + h->h_length);
need += strlen(name)+1;
need += strlen(canon)+1;
+ need += align;
- if (need > buflen) {
- freeaddrinfo(ai);
- return ERANGE;
- }
+ if (need > buflen) return ERANGE;
+ buf += align;
h->h_aliases = (void *)buf;
buf += 3*sizeof(char *);
h->h_addr_list = (void *)buf;
- buf += (i+1)*sizeof(char *);
+ buf += (cnt+1)*sizeof(char *);
h->h_name = h->h_aliases[0] = buf;
strcpy(h->h_name, canon);
@@ -79,16 +69,13 @@ int gethostbyname2_r(const char *name, int af,
h->h_aliases[2] = 0;
- for (i=0, p=ai; p; i++, p=p->ai_next) {
+ for (i=0; i<cnt; i++) {
h->h_addr_list[i] = (void *)buf;
buf += h->h_length;
- memcpy(h->h_addr_list[i],
- &((struct sockaddr_in *)p->ai_addr)->sin_addr,
- h->h_length);
+ memcpy(h->h_addr_list[i], addrs[i].addr, h->h_length);
}
h->h_addr_list[i] = 0;
*res = h;
- freeaddrinfo(ai);
return 0;
}