Subversion Repositories planix.SVN

/* posix */
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>

/* bsd extensions */
#include <sys/uio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#include "priv.h"

enum
{
        Nname= 6,
};

/*
 *  for inet addresses only
 */
struct servent*
getservbyname(char *name, char *proto)
{
        int i, fd, m, num;
        char *p, *bp;
        int nn, na;
        static struct servent s;
        static char buf[1024];
        static char *nptr[Nname+1];

        num = 1;
        for(p = name; *p; p++)
                if(!isdigit(*p))
                        num = 0;

        s.s_name = 0;

        /* connect to server */
        fd = open("/net/cs", O_RDWR);
        if(fd < 0){
                _syserrno();
                return 0;
        }

        /* construct the query, always expect an ip# back */
        if(num)
                snprintf(buf, sizeof buf, "!port=%s %s=*", name, proto);
        else
                snprintf(buf, sizeof buf, "!%s=%s port=*", proto, name);

        /* query the server */
        if(write(fd, buf, strlen(buf)) < 0){
                _syserrno();
                return 0;
        }
        lseek(fd, 0, 0);
        for(i = 0; i < sizeof(buf)-1; i += m){
                m = read(fd, buf+i, sizeof(buf) - 1 - i);
                if(m <= 0)
                        break;
                buf[i+m++] = ' ';
        }
        close(fd);
        buf[i] = 0;

        /* parse the reply */
        nn = na = 0;
        for(bp = buf;;){
                p = strchr(bp, '=');
                if(p == 0)
                        break;
                *p++ = 0;
                if(strcmp(bp, proto) == 0){
                        if(nn < Nname)
                                nptr[nn++] = p;
                } else if(strcmp(bp, "port") == 0){
                        s.s_port = htons(atoi(p));
                }
                while(*p && *p != ' ')
                        p++;
                if(*p)
                        *p++ = 0;
                bp = p;
        }
        if(nn+na == 0)
                return 0;

        nptr[nn] = 0;
        s.s_aliases = nptr;
        if(s.s_name == 0)
                s.s_name = nptr[0];

        return &s;
}