src/network/getservbyname_r.c

   1 #define _GNU_SOURCE
   2 #include <sys/socket.h>
   3 #include <netinet/in.h>
   4 #include <netdb.h>
   5 #include <inttypes.h>
   6 #include <errno.h>
   7 #include <string.h>
   8 #include "lookup.h"
   9
  10 #define ALIGN (sizeof(struct { char a; char *b; }) - sizeof(char *))
  11
  12 int getservbyname_r(const char *name, const char *prots,
  13         struct servent *se, char *buf, size_t buflen, struct servent **res)
  14 {
  15         struct service servs[MAXSERVS];
  16         int cnt, proto, align;
  17
  18         *res = 0;
  19
  20         /* Align buffer */
  21         align = -(uintptr_t)buf & ALIGN-1;
  22         if (buflen < 2*sizeof(char *)+align)
  23                 return ERANGE;
  24         buf += align;
  25
  26         if (!prots) proto = 0;
  27         else if (!strcmp(prots, "tcp")) proto = IPPROTO_TCP;
  28         else if (!strcmp(prots, "udp")) proto = IPPROTO_UDP;
  29         else return EINVAL;
  30
  31         cnt = __lookup_serv(servs, name, proto, 0, 0);
  32         if (cnt<0) switch (cnt) {
  33         case EAI_MEMORY:
  34         case EAI_SYSTEM:
  35                 return ENOMEM;
  36         default:
  37                 return ENOENT;
  38         }
  39
  40         se->s_name = (char *)name;
  41         se->s_aliases = (void *)buf;
  42         se->s_aliases[0] = se->s_name;
  43         se->s_aliases[1] = 0;
  44         se->s_port = htons(servs[0].port);
  45         se->s_proto = servs[0].proto == IPPROTO_TCP ? "tcp" : "udp";
  46
  47         *res = se;
  48         return 0;
  49 }