src/network/getaddrinfo.c

   1 #include <stdlib.h>
   2 #include <sys/socket.h>
   3 #include <netinet/in.h>
   4 #include <netdb.h>
   5 #include <string.h>
   6 #include "lookup.h"
   7
   8 int getaddrinfo(const char *restrict host, const char *restrict serv, const struct addrinfo *restrict hint, struct addrinfo **restrict res)
   9 {
  10         struct service ports[MAXSERVS];
  11         struct address addrs[MAXADDRS];
  12         char canon[256], *outcanon;
  13         int nservs, naddrs, nais, canon_len, i, j, k;
  14         int family = AF_UNSPEC, flags = 0, proto = 0;
  15         struct aibuf {
  16                 struct addrinfo ai;
  17                 union sa {
  18                         struct sockaddr_in sin;
  19                         struct sockaddr_in6 sin6;
  20                 } sa;
  21         } *out;
  22
  23         if (hint) {
  24                 family = hint->ai_family;
  25                 flags = hint->ai_flags;
  26                 proto = hint->ai_protocol;
  27
  28                 const int mask = AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST |
  29                         AI_V4MAPPED | AI_ALL | AI_ADDRCONFIG | AI_NUMERICSERV;
  30                 if ((flags & mask) != flags)
  31                         return EAI_BADFLAGS;
  32
  33                 switch (family) {
  34                 case AF_INET:
  35                 case AF_INET6:
  36                 case AF_UNSPEC:
  37                         break;
  38                 default:
  39                         return EAI_FAMILY;
  40                 }
  41
  42                 switch (hint->ai_socktype) {
  43                 case SOCK_STREAM:
  44                         switch (proto) {
  45                         case 0:
  46                                 proto = IPPROTO_TCP;
  47                         case IPPROTO_TCP:
  48                                 break;
  49                         default:
  50                                 return EAI_SERVICE;
  51                         }
  52                         break;
  53                 case SOCK_DGRAM:
  54                         switch (proto) {
  55                         case 0:
  56                                 proto = IPPROTO_UDP;
  57                         case IPPROTO_UDP:
  58                                 break;
  59                         default:
  60                                 return EAI_SERVICE;
  61                         }
  62                 case 0:
  63                         break;
  64                 default:
  65                         return EAI_SOCKTYPE;
  66                 }
  67         }
  68
  69         nservs = __lookup_serv(ports, serv, proto, flags);
  70         if (nservs < 0) return nservs;
  71
  72         naddrs = __lookup_name(addrs, canon, host, family, flags);
  73         if (naddrs < 0) return naddrs;
  74
  75         nais = nservs * naddrs;
  76         canon_len = strlen(canon);
  77         out = calloc(1, nais * sizeof(*out) + canon_len + 1);
  78         if (!out) return EAI_MEMORY;
  79
  80         if (canon_len) {
  81                 outcanon = (void *)&out[nais];
  82                 memcpy(outcanon, canon, canon_len+1);
  83         } else {
  84                 outcanon = 0;
  85         }
  86
  87         for (k=i=0; i<naddrs; i++) for (j=0; j<nservs; j++, k++) {
  88                 out[k].ai = (struct addrinfo){
  89                         .ai_family = addrs[i].family,
  90                         .ai_socktype = ports[j].proto == IPPROTO_TCP
  91                                 ? SOCK_STREAM : SOCK_DGRAM,
  92                         .ai_protocol = ports[j].proto,
  93                         .ai_addrlen = addrs[i].family == AF_INET
  94                                 ? sizeof(struct sockaddr_in)
  95                                 : sizeof(struct sockaddr_in6),
  96                         .ai_addr = (void *)&out[k].sa,
  97                         .ai_canonname = outcanon,
  98                         .ai_next = &out[k+1].ai };
  99                 switch (addrs[i].family) {
 100                 case AF_INET:
 101                         out[k].sa.sin.sin_family = AF_INET;
 102                         out[k].sa.sin.sin_port = htons(ports[j].port);
 103                         memcpy(&out[k].sa.sin.sin_addr, &addrs[i].addr, 4);
 104                         break;
 105                 case AF_INET6:
 106                         out[k].sa.sin6.sin6_family = AF_INET6;
 107                         out[k].sa.sin6.sin6_port = htons(ports[j].port);
 108                         memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16);
 109                         break;
 110                 }
 111         }
 112         out[nais-1].ai.ai_next = 0;
 113         *res = &out->ai;
 114         return 0;
 115 }