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/*
* This program is in the public domain and may be used freely by anyone
* who wants to.
*
* Please send bug fixes/bug reports to: Peter Eriksson <pen@lysator.liu.se>
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <pwd.h>
#include <nlist.h>
#include <kvm.h>
#include <unistd.h>
#include "identd.h"
#include "error.h"
#define IO_TIMEOUT 30 /* Timeout I/O operations after N seconds */
int check_noident __P((char *));
ssize_t timed_read __P((int, void *, size_t, time_t));
ssize_t timed_write __P((int, const void *, size_t, time_t));
void gentoken __P((char *, int));
/*
* A small routine to check for the existance of the ".noident"
* file in a users home directory.
*/
int
check_noident(homedir)
char *homedir;
{
char path[MAXPATHLEN];
struct stat st;
if (!homedir)
return 0;
if (snprintf(path, sizeof path, "%s/.noident", homedir) >= sizeof path)
return 0;
if (stat(path, &st) == 0)
return 1;
return 0;
}
static char token0cnv[] = "abcdefghijklmnopqrstuvwxyz";
static char tokencnv[] = "abcdefghijklmnopqrstuvwxyz0123456789";
void
gentoken(buf, len)
char *buf;
int len;
{
char *p;
if (len == 0)
return;
for (p = buf; len > 1; p++, len--) {
if (p == buf)
*p = token0cnv[arc4random() % (sizeof token0cnv-1)];
else
*p = tokencnv[arc4random() % (sizeof tokencnv-1)];
}
*p = '\0';
}
/*
* Returns 0 on timeout, -1 on error, #bytes read on success.
*/
ssize_t
timed_read(fd, buf, siz, timeout)
int fd;
void *buf;
size_t siz;
time_t timeout;
{
int error, tot = 0, i, r;
char *p = buf;
fd_set readfds;
struct timeval tv, start, after, duration, tmp;
tv.tv_sec = timeout;
tv.tv_usec = 0;
while (1) {
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
gettimeofday(&start, NULL);
if ((error = select(fd + 1, &readfds, 0, 0, &tv)) <= 0)
return error;
r = read(fd, p, siz - tot);
if (r == -1 || r == 0)
return (r);
for (i = 0; i < r; i++)
if (p[i] == '\r' || p[i] == '\n') {
tot += r;
return (tot);
}
gettimeofday(&after, NULL);
timersub(&start, &after, &duration);
timersub(&tv, &duration, &tmp);
tv = tmp;
if (tv.tv_sec < 0 || !timerisset(&tv))
return (tot);
tot += r;
p += r;
}
}
/*
* Returns 0 on timeout, -1 on error, #bytes read on success.
*/
ssize_t
timed_write(fd, buf, siz, timeout)
int fd;
const void *buf;
size_t siz;
time_t timeout;
{
int error;
fd_set writeds;
struct timeval tv;
FD_ZERO(&writeds);
FD_SET(fd, &writeds);
tv.tv_sec = timeout;
tv.tv_usec = 0;
if ((error = select(fd + 1, 0, &writeds, 0, &tv)) <= 0)
return error;
return(write(fd, buf, siz));
}
int
parse(fd, laddr, faddr)
int fd;
struct in_addr *laddr, *faddr;
{
char buf[BUFSIZ], *p;
struct in_addr laddr2, faddr2;
struct passwd *pw;
int n;
uid_t uid;
if (debug_flag && syslog_flag)
syslog(LOG_DEBUG, "In function parse()");
if (debug_flag && syslog_flag)
syslog(LOG_DEBUG, " Before read from remote host");
faddr2 = *faddr;
laddr2 = *laddr;
lport = fport = 0;
/* Read query from client */
if ((n = timed_read(fd, buf, sizeof(buf) - 1, IO_TIMEOUT)) <= 0) {
if (syslog_flag)
syslog(LOG_NOTICE, "read from %s: %m", gethost(faddr));
n = snprintf(buf, sizeof(buf),
"%d , %d : ERROR : UNKNOWN-ERROR\r\n", lport, fport);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
buf[n] = '\0';
/* Pull out local and remote ports */
p = buf;
while (*p != '\0' && isspace(*p))
p++;
if ((p = strtok(p, " \t,"))) {
lport = atoi(p);
if ((p = strtok(NULL, " \t,")))
fport = atoi(p);
}
if (lport < 1 || lport > 65535 || fport < 1 || fport > 65535) {
if (syslog_flag)
syslog(LOG_NOTICE,
"scanf: invalid-port(s): %d , %d from %s",
lport, fport, gethost(faddr));
n = snprintf(buf, sizeof(buf), "%d , %d : ERROR : %s\r\n",
lport, fport, unknown_flag ? "UNKNOWN-ERROR" : "INVALID-PORT");
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
if (syslog_flag && verbose_flag)
syslog(LOG_NOTICE, "request for (%d,%d) from %s",
lport, fport, gethost(faddr));
if (debug_flag && syslog_flag)
syslog(LOG_DEBUG, " After fscanf(), before k_getuid()");
/*
* Next - get the specific TCP connection and return the
* uid - user number.
*
*/
if (k_getuid(&faddr2, htons(fport), laddr,
htons(lport), &uid) == -1) {
if (syslog_flag)
syslog(LOG_DEBUG, "Returning: %d , %d : NO-USER",
lport, fport);
n = snprintf(buf, sizeof(buf), "%d , %d : ERROR : %s\r\n",
lport, fport, unknown_flag ? "UNKNOWN-ERROR" : "NO-USER");
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
if (debug_flag && syslog_flag)
syslog(LOG_DEBUG, " After k_getuid(), before getpwuid()");
pw = getpwuid(uid);
if (!pw) {
if (syslog_flag)
syslog(LOG_WARNING,
"getpwuid() could not map uid (%d) to name",
uid);
n = snprintf(buf, sizeof(buf),
"%d , %d : USERID : OTHER%s%s :%d\r\n",
lport, fport, charset_name ? " , " : "",
charset_name ? charset_name : "", uid);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
if (syslog_flag)
syslog(LOG_DEBUG, "Successful lookup: %d , %d : %s",
lport, fport, pw->pw_name);
if (noident_flag && check_noident(pw->pw_dir)) {
if (syslog_flag && verbose_flag)
syslog(LOG_NOTICE,
"user %s requested HIDDEN-USER for host %s: %d, %d",
pw->pw_name, gethost(faddr), lport, fport);
n = snprintf(buf, sizeof(buf),
"%d , %d : ERROR : HIDDEN-USER\r\n", lport, fport);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
if (token_flag) {
char token[21];
gentoken(token, sizeof token);
syslog(LOG_NOTICE, "token %s == uid %u (%s)", token, uid,
pw->pw_name);
n = snprintf(buf, sizeof(buf),
"%d , %d : USERID : OTHER%s%s :%s\r\n",
lport, fport, charset_name ? " , " : "",
charset_name ? charset_name : "", token);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
if (number_flag) {
n = snprintf(buf, sizeof(buf),
"%d , %d : USERID : OTHER%s%s :%d\r\n",
lport, fport, charset_name ? " , " : "",
charset_name ? charset_name : "", uid);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
n = snprintf(buf, sizeof(buf), "%d , %d : USERID : %s%s%s :%s\r\n",
lport, fport, other_flag ? "OTHER" : "UNIX",
charset_name ? " , " : "",
charset_name ? charset_name : "", pw->pw_name);
if (timed_write(fd, buf, n, IO_TIMEOUT) != n && syslog_flag) {
syslog(LOG_NOTICE, "write to %s: %m", gethost(faddr));
return 1;
}
return 0;
}
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