81 lines
1.6 KiB
C
81 lines
1.6 KiB
C
#define _GNU_SOURCE
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#include <sys/socket.h>
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#include <netdb.h>
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#include <string.h>
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#include <netinet/in.h>
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#include <errno.h>
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#include <stdint.h>
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#include "lookup.h"
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int gethostbyname2_r(const char *name, int af,
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struct hostent *h, char *buf, size_t buflen,
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struct hostent **res, int *err)
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{
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struct address addrs[MAXADDRS];
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char canon[256];
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int i, cnt;
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size_t align, need;
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*res = 0;
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cnt = __lookup_name(addrs, canon, name, af, AI_CANONNAME);
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if (cnt<0) switch (cnt) {
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case EAI_NONAME:
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*err = HOST_NOT_FOUND;
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return ENOENT;
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case EAI_AGAIN:
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*err = TRY_AGAIN;
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return EAGAIN;
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default:
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case EAI_FAIL:
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*err = NO_RECOVERY;
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return EBADMSG;
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case EAI_MEMORY:
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case EAI_SYSTEM:
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*err = NO_RECOVERY;
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return errno;
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}
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h->h_addrtype = af;
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h->h_length = af==AF_INET6 ? 16 : 4;
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/* Align buffer */
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align = -(uintptr_t)buf & sizeof(char *)-1;
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need = 4*sizeof(char *);
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need += (cnt + 1) * (sizeof(char *) + h->h_length);
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need += strlen(name)+1;
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need += strlen(canon)+1;
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need += align;
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if (need > buflen) return ERANGE;
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buf += align;
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h->h_aliases = (void *)buf;
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buf += 3*sizeof(char *);
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h->h_addr_list = (void *)buf;
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buf += (cnt+1)*sizeof(char *);
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for (i=0; i<cnt; i++) {
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h->h_addr_list[i] = (void *)buf;
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buf += h->h_length;
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memcpy(h->h_addr_list[i], addrs[i].addr, h->h_length);
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}
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h->h_addr_list[i] = 0;
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h->h_name = h->h_aliases[0] = buf;
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strcpy(h->h_name, canon);
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buf += strlen(h->h_name)+1;
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if (strcmp(h->h_name, name)) {
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h->h_aliases[1] = buf;
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strcpy(h->h_aliases[1], name);
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buf += strlen(h->h_aliases[1])+1;
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} else h->h_aliases[1] = 0;
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h->h_aliases[2] = 0;
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*res = h;
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return 0;
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}
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