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#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <ctype.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include "lookup.h"
int __lookup_serv(struct service buf[static MAXSERVS], const char *name, int proto, int socktype, int flags)
{
char line[128];
int cnt = 0;
char *p, *z = "";
unsigned long port = 0;
switch (socktype) {
case SOCK_STREAM:
switch (proto) {
case 0:
proto = IPPROTO_TCP;
case IPPROTO_TCP:
break;
default:
return EAI_SERVICE;
}
break;
case SOCK_DGRAM:
switch (proto) {
case 0:
proto = IPPROTO_UDP;
case IPPROTO_UDP:
break;
default:
return EAI_SERVICE;
}
case 0:
break;
default:
if (name) return EAI_SERVICE;
buf[0].port = 0;
buf[0].proto = proto;
buf[0].socktype = socktype;
return 1;
}
if (name) {
if (!*name) return EAI_SERVICE;
port = strtoul(name, &z, 10);
}
if (!*z) {
if (port > 65535) return EAI_SERVICE;
if (proto != IPPROTO_UDP) {
buf[cnt].port = port;
buf[cnt].socktype = SOCK_STREAM;
buf[cnt++].proto = IPPROTO_TCP;
}
if (proto != IPPROTO_TCP) {
buf[cnt].port = port;
buf[cnt].socktype = SOCK_DGRAM;
buf[cnt++].proto = IPPROTO_UDP;
}
return cnt;
}
if (flags & AI_NUMERICSERV) return EAI_NONAME;
size_t l = strlen(name);
FILE *f = fopen("/etc/services", "rb");
if (!f) switch (errno) {
case ENOENT:
case ENOTDIR:
case EACCES:
return EAI_SERVICE;
default:
return EAI_SYSTEM;
}
while (fgets(line, sizeof line, f) && cnt < MAXSERVS) {
if ((p=strchr(line, '#'))) *p++='\n', *p=0;
/* Find service name */
for(p=line; (p=strstr(p, name)); p++) {
if (p>line && !isspace(p[-1])) continue;
if (p[l] && !isspace(p[l])) continue;
break;
}
if (!p) continue;
/* Skip past canonical name at beginning of line */
for (p=line; *p && !isspace(*p); p++);
port = strtoul(p, &z, 10);
if (port > 65535 || z==p) continue;
if (!strncmp(z, "/udp", 4)) {
if (proto == IPPROTO_TCP) continue;
buf[cnt].port = port;
buf[cnt].socktype = SOCK_DGRAM;
buf[cnt++].proto = IPPROTO_UDP;
}
if (!strncmp(z, "/tcp", 4)) {
if (proto == IPPROTO_UDP) continue;
buf[cnt].port = port;
buf[cnt].socktype = SOCK_STREAM;
buf[cnt++].proto = IPPROTO_TCP;
}
}
fclose(f);
return cnt > 0 ? cnt : EAI_SERVICE;
}
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