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path: root/src/network/gethostbyname2_r.c
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Diffstat (limited to 'src/network/gethostbyname2_r.c')
-rw-r--r--src/network/gethostbyname2_r.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/src/network/gethostbyname2_r.c b/src/network/gethostbyname2_r.c
new file mode 100644
index 00000000..c2ed75b4
--- /dev/null
+++ b/src/network/gethostbyname2_r.c
@@ -0,0 +1,99 @@
+#define _GNU_SOURCE
+
+#include <sys/socket.h>
+#include <netdb.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <inttypes.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;
+
+ af = hint.ai_family;
+
+ /* Align buffer */
+ i = (uintptr_t)buf & sizeof(char *)-1;
+ if (i) {
+ if (buflen < sizeof(char *)-i) {
+ errno = ERANGE;
+ return -1;
+ }
+ buf += sizeof(char *)-i;
+ buflen -= sizeof(char *)-i;
+ }
+
+ getaddrinfo(name, 0, &hint, &ai);
+ switch (getaddrinfo(name, 0, &hint, &ai)) {
+ case EAI_NONAME:
+ *err = HOST_NOT_FOUND;
+ return -1;
+ case EAI_AGAIN:
+ *err = TRY_AGAIN;
+ return -1;
+ default:
+ case EAI_MEMORY:
+ case EAI_SYSTEM:
+ case EAI_FAIL:
+ *err = NO_RECOVERY;
+ return -1;
+ case 0:
+ break;
+ }
+
+ h->h_addrtype = af;
+ h->h_length = af==AF_INET6 ? 16 : 4;
+
+ canon = ai->ai_canonname ? ai->ai_canonname : name;
+ need = 4*sizeof(char *);
+ for (i=0, p=ai; p; i++, p=p->ai_next)
+ need += sizeof(char *) + h->h_length;
+ need += strlen(name)+1;
+ need += strlen(canon)+1;
+
+ if (need > buflen) {
+ freeaddrinfo(ai);
+ errno = ERANGE;
+ return -1;
+ }
+
+ h->h_aliases = (void *)buf;
+ buf += 3*sizeof(char *);
+ h->h_addr_list = (void *)buf;
+ buf += (i+1)*sizeof(char *);
+
+ h->h_name = h->h_aliases[0] = buf;
+ strcpy(h->h_name, canon);
+ buf += strlen(h->h_name)+1;
+
+ if (strcmp(h->h_name, name)) {
+ h->h_aliases[1] = buf;
+ strcpy(h->h_aliases[1], name);
+ buf += strlen(h->h_aliases[1])+1;
+ } else h->h_aliases[1] = 0;
+
+ h->h_aliases[2] = 0;
+
+ for (i=0, p=ai; p; i++, p=p->ai_next) {
+ 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);
+ }
+ h->h_addr_list[i] = 0;
+
+ *res = h;
+ freeaddrinfo(ai);
+ return 0;
+}