nsz Git - musl/blob - src/network/gethostbyname2_r.c

   1 #define _GNU_SOURCE
   2
   3 #include <sys/socket.h>
   4 #include <netdb.h>
   5 #include <string.h>
   6 #include <netinet/in.h>
   7 #include <errno.h>
   8 #include <inttypes.h>
   9
  10 int gethostbyname2_r(const char *name, int af,
  11         struct hostent *h, char *buf, size_t buflen,
  12         struct hostent **res, int *err)
  13 {
  14         struct addrinfo hint = {
  15                 .ai_family = af==AF_INET6 ? af : AF_INET,
  16                 .ai_flags = AI_CANONNAME
  17         };
  18         struct addrinfo *ai, *p;
  19         int i;
  20         size_t need;
  21         const char *canon;
  22
  23         af = hint.ai_family;
  24
  25         /* Align buffer */
  26         i = (uintptr_t)buf & sizeof(char *)-1;
  27         if (i) {
  28                 if (buflen < sizeof(char *)-i) {
  29                         errno = ERANGE;
  30                         return -1;
  31                 }
  32                 buf += sizeof(char *)-i;
  33                 buflen -= sizeof(char *)-i;
  34         }
  35
  36         getaddrinfo(name, 0, &hint, &ai);
  37         switch (getaddrinfo(name, 0, &hint, &ai)) {
  38         case EAI_NONAME:
  39                 *err = HOST_NOT_FOUND;
  40                 return -1;
  41         case EAI_AGAIN:
  42                 *err = TRY_AGAIN;
  43                 return -1;
  44         default:
  45         case EAI_MEMORY:
  46         case EAI_SYSTEM:
  47         case EAI_FAIL:
  48                 *err = NO_RECOVERY;
  49                 return -1;
  50         case 0:
  51                 break;
  52         }
  53
  54         h->h_addrtype = af;
  55         h->h_length = af==AF_INET6 ? 16 : 4;
  56
  57         canon = ai->ai_canonname ? ai->ai_canonname : name;
  58         need = 4*sizeof(char *);
  59         for (i=0, p=ai; p; i++, p=p->ai_next)
  60                 need += sizeof(char *) + h->h_length;
  61         need += strlen(name)+1;
  62         need += strlen(canon)+1;
  63
  64         if (need > buflen) {
  65                 freeaddrinfo(ai);
  66                 errno = ERANGE;
  67                 return -1;
  68         }
  69
  70         h->h_aliases = (void *)buf;
  71         buf += 3*sizeof(char *);
  72         h->h_addr_list = (void *)buf;
  73         buf += (i+1)*sizeof(char *);
  74
  75         h->h_name = h->h_aliases[0] = buf;
  76         strcpy(h->h_name, canon);
  77         buf += strlen(h->h_name)+1;
  78
  79         if (strcmp(h->h_name, name)) {
  80                 h->h_aliases[1] = buf;
  81                 strcpy(h->h_aliases[1], name);
  82                 buf += strlen(h->h_aliases[1])+1;
  83         } else h->h_aliases[1] = 0;
  84
  85         h->h_aliases[2] = 0;
  86
  87         for (i=0, p=ai; p; i++, p=p->ai_next) {
  88                 h->h_addr_list[i] = (void *)buf;
  89                 buf += h->h_length;
  90                 memcpy(h->h_addr_list[i],
  91                         &((struct sockaddr_in *)p->ai_addr)->sin_addr,
  92                         h->h_length);
  93         }
  94         h->h_addr_list[i] = 0;
  95
  96         *res = h;
  97         freeaddrinfo(ai);
  98         return 0;
  99 }