src/network/lookup_serv.c

   1 #include <sys/socket.h>
   2 #include <netinet/in.h>
   3 #include <netdb.h>
   4 #include <ctype.h>
   5 #include <string.h>
   6 #include <stdlib.h>
   7 #include <fcntl.h>
   8 #include <errno.h>
   9 #include "lookup.h"
  10 #include "stdio_impl.h"
  11
  12 int __lookup_serv(struct service buf[static MAXSERVS], const char *name, int proto, int socktype, int flags)
  13 {
  14         char line[128];
  15         int cnt = 0;
  16         char *p, *z = "";
  17         unsigned long port = 0;
  18
  19         switch (socktype) {
  20         case SOCK_STREAM:
  21                 switch (proto) {
  22                 case 0:
  23                         proto = IPPROTO_TCP;
  24                 case IPPROTO_TCP:
  25                         break;
  26                 default:
  27                         return EAI_SERVICE;
  28                 }
  29                 break;
  30         case SOCK_DGRAM:
  31                 switch (proto) {
  32                 case 0:
  33                         proto = IPPROTO_UDP;
  34                 case IPPROTO_UDP:
  35                         break;
  36                 default:
  37                         return EAI_SERVICE;
  38                 }
  39         case 0:
  40                 break;
  41         default:
  42                 if (name) return EAI_SERVICE;
  43                 buf[0].port = 0;
  44                 buf[0].proto = proto;
  45                 buf[0].socktype = socktype;
  46                 return 1;
  47         }
  48
  49         if (name) {
  50                 if (!*name) return EAI_SERVICE;
  51                 port = strtoul(name, &z, 10);
  52         }
  53         if (!*z) {
  54                 if (port > 65535) return EAI_SERVICE;
  55                 if (proto != IPPROTO_UDP) {
  56                         buf[cnt].port = port;
  57                         buf[cnt].socktype = SOCK_STREAM;
  58                         buf[cnt++].proto = IPPROTO_TCP;
  59                 }
  60                 if (proto != IPPROTO_TCP) {
  61                         buf[cnt].port = port;
  62                         buf[cnt].socktype = SOCK_DGRAM;
  63                         buf[cnt++].proto = IPPROTO_UDP;
  64                 }
  65                 return cnt;
  66         }
  67
  68         if (flags & AI_NUMERICSERV) return EAI_NONAME;
  69
  70         size_t l = strlen(name);
  71
  72         unsigned char _buf[1032];
  73         FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
  74         if (!f) switch (errno) {
  75         case ENOENT:
  76         case ENOTDIR:
  77         case EACCES:
  78                 return EAI_SERVICE;
  79         default:
  80                 return EAI_SYSTEM;
  81         }
  82
  83         while (fgets(line, sizeof line, f) && cnt < MAXSERVS) {
  84                 if ((p=strchr(line, '#'))) *p++='\n', *p=0;
  85
  86                 /* Find service name */
  87                 for(p=line; (p=strstr(p, name)); p++) {
  88                         if (p>line && !isspace(p[-1])) continue;
  89                         if (p[l] && !isspace(p[l])) continue;
  90                         break;
  91                 }
  92                 if (!p) continue;
  93
  94                 /* Skip past canonical name at beginning of line */
  95                 for (p=line; *p && !isspace(*p); p++);
  96
  97                 port = strtoul(p, &z, 10);
  98                 if (port > 65535 || z==p) continue;
  99                 if (!strncmp(z, "/udp", 4)) {
 100                         if (proto == IPPROTO_TCP) continue;
 101                         buf[cnt].port = port;
 102                         buf[cnt].socktype = SOCK_DGRAM;
 103                         buf[cnt++].proto = IPPROTO_UDP;
 104                 }
 105                 if (!strncmp(z, "/tcp", 4)) {
 106                         if (proto == IPPROTO_UDP) continue;
 107                         buf[cnt].port = port;
 108                         buf[cnt].socktype = SOCK_STREAM;
 109                         buf[cnt++].proto = IPPROTO_TCP;
 110                 }
 111         }
 112         __fclose_ca(f);
 113         return cnt > 0 ? cnt : EAI_SERVICE;
 114 }