lookup_serv.c (2413B)
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[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 }