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