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/* ==================================================================
* CHILD.C
* -------
*
* This module is responsible for running
* efingerd as a child service of inetd.
* It cares for this child like a good parent should,
* providing vital nutrients, love, support, child
* reapers, and built in functionality to have the
* child kill itself if it stays alive too long.
*
* ==================================================================
*/
#include "efingerd.h"
#ifdef DONT_HAVE_LIBIDENT
# define ident_id(a,b) NULL
#else
# include "ident.h"
#endif
#include <pwd.h>
#include <sys/stat.h>
static int s_in = -1, s_out = -1;
/* ------------------------------------------------------------------
* lookup_addr:
* if resolve_addr, try to reverse resolve the address.
* else return the numerical ip.
* ------------------------------------------------------------------
*/
static char *lookup_addr(struct in_addr in)
{
static char addr[100];
struct hostent *he;
if (resolve_addr) {
he = gethostbyaddr((char *) &in, sizeof(struct in_addr), AF_INET);
if (he == NULL)
strncpy(addr, inet_ntoa(in), sizeof(addr));
else
strncpy(addr, he->h_name, sizeof(addr));
} else
strncpy(addr, inet_ntoa(in), sizeof(addr));
addr[sizeof(addr)-1] = '\0';
return addr;
}
/* ----------------------------------------------------------------
* killtic:
* kill this process after a pre-determined
* timeout period. (SIGALRM handler)
* ----------------------------------------------------------------
*/
void killtic(int s)
{
killsock(s_in);
killsock(s_out);
exit(0);
}
void alm(int i)
{
i++;
signal(SIGINT, SIG_IGN); /* Don't want to kill ourselves */
kill(-getpgrp(), SIGINT);
sleep(TIME_UNTIL_KILL); /* 3 second for the process to terminate itself */
kill(-getpgrp(), SIGKILL);
exit(0);
}
void safe_exec(char *cmd, char *arg1, char *arg2, char *arg3)
{
int pid;
if ((pid = fork()) == 0) { /* Program inherits the socket */
execl(cmd, cmd, arg1, arg2, arg3, NULL);
_exit(0); /* Should never happen */
}
signal(SIGALRM, alm);
alarm(TIME_UNTIL_INT);
wait(NULL);
}
void do_finger(char *user, char *identity, char *remote_address,
int sd_out)
{
struct passwd *passs;
struct stat st;
char buff[200], path[200];
char *poi;
if (strlen(user) == 0) {
safe_exec(EFINGER_LIST, identity, remote_address, NULL);
} else {
passs = getpwnam(user);
if (passs == NULL) {
safe_exec(EFINGER_NOUSER, identity, remote_address, user);
} else {
if (display_full_name) {
strncpy(buff, passs->pw_gecos, sizeof(buff) - 1);
buff[sizeof(buff) - 1] = '\0';
for (poi = buff; (*poi) != '\0'; poi++)
if ((*poi) == ',')
(*poi) = ' ';
client_reply(sd_out, buff);
client_reply(sd_out, "\r\n");
};
if (sizeof(path) >=
strlen(passs->pw_dir) + sizeof(EFINGER_USER_FILE) + 1) {
strncpy(path, passs->pw_dir, sizeof(path));
strcat(path, "/");
strcat(path, EFINGER_USER_FILE);
if (ignore_user || stat(path, &st)) {
safe_exec(EFINGER_LUSER, identity, remote_address,
user);
} else {
safe_exec(path, identity, remote_address, user);
}
}
}
}
client_reply(sd_out, "\r\n");
}
/* ------------------------------------------------------------------
* inetd_service:
* this function does the actual pipe handling
* user lookups, replies, etcetera.
* ------------------------------------------------------------------
*/
void inetd_service(int sd_in, int sd_out)
{
struct in_addr laddr, raddr;
struct sockaddr_in sin;
char buffer[MAX_SOCK_LENGTH];
int sinsize = sizeof(struct sockaddr_in);
int reqstat;
char *identity, *remote_address;
char *nullident = "(null)";
s_in = sd_in;
s_out = sd_out;
if (getpeername(sd_in, (struct sockaddr *) &sin, &sinsize) == -1) {
syslog(LOG_NOTICE, "error: getpeername: %s", strerror(errno));
client_reply(sd_out, "401 getpeername failed\r\n");
return; /* the error implies the net is down, but try */
}
raddr = sin.sin_addr;
if (getsockname(sd_in, (struct sockaddr *) &sin, &sinsize) == -1) {
syslog(LOG_ERR, "error: getsockname: %s", strerror(errno));
client_reply(sd_out, "402 getsockname failed\r\n");
return;
}
laddr = sin.sin_addr;
reqstat = get_request(sd_in, buffer, MAX_SOCK_LENGTH);
identity = ident_id(sd_in, IDENT_TIME);
if (identity == NULL)
identity = nullident;
remote_address = lookup_addr(raddr);
do_finger(buffer, identity, remote_address, sd_out);
}
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