freebsd-skq/usr.sbin/inetd/builtins.c
sheldonh 4f4f7569f6 Move code for all builtin services from inetd.c to builtins.c, including
the Green Piece. :-)

In future, new builtin services are less likely to need to touch the
already tangled inetd.c .
1999-07-22 14:11:26 +00:00

506 lines
10 KiB
C

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/ucred.h>
#include <sys/uio.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include "inetd.h"
extern int debug;
extern struct servtab *servtab;
char ring[128];
char *endring;
int check_loop __P((struct sockaddr_in *, struct servtab *sep));
void inetd_setproctitle __P((char *, int));
struct biltin biltins[] = {
/* Echo received data */
{ "echo", SOCK_STREAM, 1, -1, echo_stream },
{ "echo", SOCK_DGRAM, 0, 1, echo_dg },
/* Internet /dev/null */
{ "discard", SOCK_STREAM, 1, -1, discard_stream },
{ "discard", SOCK_DGRAM, 0, 1, discard_dg },
/* Return 32 bit time since 1970 */
{ "time", SOCK_STREAM, 0, -1, machtime_stream },
{ "time", SOCK_DGRAM, 0, 1, machtime_dg },
/* Return human-readable time */
{ "daytime", SOCK_STREAM, 0, -1, daytime_stream },
{ "daytime", SOCK_DGRAM, 0, 1, daytime_dg },
/* Familiar character generator */
{ "chargen", SOCK_STREAM, 1, -1, chargen_stream },
{ "chargen", SOCK_DGRAM, 0, 1, chargen_dg },
{ "tcpmux", SOCK_STREAM, 1, -1, (void (*)())tcpmux },
{ "auth", SOCK_STREAM, 1, -1, ident_stream },
{ NULL }
};
void
initring()
{
int i;
endring = ring;
for (i = 0; i <= 128; ++i)
if (isprint(i))
*endring++ = i;
}
/* ARGSUSED */
void
chargen_dg(s, sep) /* Character generator */
int s;
struct servtab *sep;
{
struct sockaddr_in sin;
static char *rs;
int len, size;
char text[LINESIZ+2];
if (endring == 0) {
initring();
rs = ring;
}
size = sizeof(sin);
if (recvfrom(s, text, sizeof(text), 0,
(struct sockaddr *)&sin, &size) < 0)
return;
if (check_loop(&sin, sep))
return;
if ((len = endring - rs) >= LINESIZ)
memmove(text, rs, LINESIZ);
else {
memmove(text, rs, len);
memmove(text + len, ring, LINESIZ - len);
}
if (++rs == endring)
rs = ring;
text[LINESIZ] = '\r';
text[LINESIZ + 1] = '\n';
(void) sendto(s, text, sizeof(text), 0,
(struct sockaddr *)&sin, sizeof(sin));
}
/* ARGSUSED */
void
chargen_stream(s, sep) /* Character generator */
int s;
struct servtab *sep;
{
int len;
char *rs, text[LINESIZ+2];
inetd_setproctitle(sep->se_service, s);
if (!endring) {
initring();
rs = ring;
}
text[LINESIZ] = '\r';
text[LINESIZ + 1] = '\n';
for (rs = ring;;) {
if ((len = endring - rs) >= LINESIZ)
memmove(text, rs, LINESIZ);
else {
memmove(text, rs, len);
memmove(text + len, ring, LINESIZ - len);
}
if (++rs == endring)
rs = ring;
if (write(s, text, sizeof(text)) != sizeof(text))
break;
}
exit(0);
}
/* ARGSUSED */
void
daytime_dg(s, sep) /* Return human-readable time of day */
int s;
struct servtab *sep;
{
char buffer[256];
time_t clock;
struct sockaddr_in sin;
int size;
clock = time((time_t *) 0);
size = sizeof(sin);
if (recvfrom(s, buffer, sizeof(buffer), 0,
(struct sockaddr *)&sin, &size) < 0)
return;
if (check_loop(&sin, sep))
return;
(void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
(void) sendto(s, buffer, strlen(buffer), 0,
(struct sockaddr *)&sin, sizeof(sin));
}
/* ARGSUSED */
void
daytime_stream(s, sep) /* Return human-readable time of day */
int s;
struct servtab *sep;
{
char buffer[256];
time_t clock;
clock = time((time_t *) 0);
(void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
(void) write(s, buffer, strlen(buffer));
}
/* ARGSUSED */
void
discard_dg(s, sep) /* Discard service -- ignore data */
int s;
struct servtab *sep;
{
char buffer[BUFSIZE];
(void) read(s, buffer, sizeof(buffer));
}
/* ARGSUSED */
void
discard_stream(s, sep) /* Discard service -- ignore data */
int s;
struct servtab *sep;
{
int ret;
char buffer[BUFSIZE];
inetd_setproctitle(sep->se_service, s);
while (1) {
while ((ret = read(s, buffer, sizeof(buffer))) > 0)
;
if (ret == 0 || errno != EINTR)
break;
}
exit(0);
}
/* ARGSUSED */
void
echo_dg(s, sep) /* Echo service -- echo data back */
int s;
struct servtab *sep;
{
char buffer[BUFSIZE];
int i, size;
struct sockaddr_in sin;
size = sizeof(sin);
if ((i = recvfrom(s, buffer, sizeof(buffer), 0,
(struct sockaddr *)&sin, &size)) < 0)
return;
if (check_loop(&sin, sep))
return;
(void) sendto(s, buffer, i, 0, (struct sockaddr *)&sin,
sizeof(sin));
}
/* ARGSUSED */
void
echo_stream(s, sep) /* Echo service -- echo data back */
int s;
struct servtab *sep;
{
char buffer[BUFSIZE];
int i;
inetd_setproctitle(sep->se_service, s);
while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
write(s, buffer, i) > 0)
;
exit(0);
}
/* ARGSUSED */
void
iderror(lport, fport, fp, er)
int lport, fport, er;
FILE *fp;
{
fprintf(fp, "%d , %d : ERROR : %s\r\n", lport, fport,
er == -1 ? "HIDDEN-USER" : er ? strerror(er) : "UNKNOWN-ERROR");
fflush(fp);
fclose(fp);
exit(0);
}
/* ARGSUSED */
void
ident_stream(s, sep) /* Ident service */
int s;
struct servtab *sep;
{
struct sockaddr_in sin[2];
struct ucred uc;
struct passwd *pw;
FILE *fp;
char buf[BUFSIZE], *cp, **av;
int len, c, rflag = 0, fflag = 0, argc = 0;
u_short lport, fport;
inetd_setproctitle(sep->se_service, s);
optind = 1;
optreset = 1;
for (av = sep->se_argv; *av; av++)
argc++;
if (argc) {
while ((c = getopt(argc, sep->se_argv, "fr")) != -1)
switch (c) {
case 'f':
fflag = 1;
break;
case 'r':
rflag = 1;
break;
default:
break;
}
}
fp = fdopen(s, "r+");
len = sizeof(sin[0]);
if (getsockname(s, (struct sockaddr *)&sin[0], &len) == -1)
iderror(0, 0, fp, errno);
len = sizeof(sin[1]);
if (getpeername(s, (struct sockaddr *)&sin[1], &len) == -1)
iderror(0, 0, fp, errno);
errno = 0;
if (fgets(buf, sizeof(buf), fp) == NULL)
iderror(0, 0, fp, errno);
buf[BUFSIZE - 1] = '\0';
strtok(buf, "\r\n");
cp = strtok(buf, ",");
if (cp == NULL || sscanf(cp, "%hu", &lport) != 1)
iderror(0, 0, fp, 0);
cp = strtok(NULL, ",");
if (cp == NULL || sscanf(cp, "%hu", &fport) != 1)
iderror(0, 0, fp, 0);
if (!rflag)
iderror(lport, fport, fp, -1);
sin[0].sin_port = htons(lport);
sin[1].sin_port = htons(fport);
len = sizeof(uc);
if (sysctlbyname("net.inet.tcp.getcred", &uc, &len, sin,
sizeof(sin)) == -1)
iderror(lport, fport, fp, errno);
pw = getpwuid(uc.cr_uid);
if (pw == NULL)
iderror(lport, fport, fp, errno);
if (fflag) {
FILE *fakeid = NULL;
char fakeid_path[PATH_MAX];
struct stat sb;
seteuid(pw->pw_uid);
setegid(pw->pw_gid);
snprintf(fakeid_path, sizeof(fakeid_path), "%s/.fakeid",
pw->pw_dir);
if ((fakeid = fopen(fakeid_path, "r")) != NULL &&
fstat(fileno(fakeid), &sb) != -1 && S_ISREG(sb.st_mode)) {
buf[sizeof(buf) - 1] = '\0';
if (fgets(buf, sizeof(buf), fakeid) == NULL) {
cp = pw->pw_name;
fclose(fakeid);
goto printit;
}
fclose(fakeid);
strtok(buf, "\r\n");
if (strlen(buf) > 16)
buf[16] = '\0';
cp = buf;
while (isspace(*cp))
cp++;
strtok(cp, " \t");
if (!*cp || getpwnam(cp))
cp = getpwuid(uc.cr_uid)->pw_name;
} else
cp = pw->pw_name;
} else
cp = pw->pw_name;
printit:
fprintf(fp, "%d , %d : USERID : FreeBSD :%s\r\n", lport, fport,
cp);
fflush(fp);
fclose(fp);
exit(0);
}
/*
* Return a machine readable date and time, in the form of the
* number of seconds since midnight, Jan 1, 1900. Since gettimeofday
* returns the number of seconds since midnight, Jan 1, 1970,
* we must add 2208988800 seconds to this figure to make up for
* some seventy years Bell Labs was asleep.
*/
unsigned long
machtime()
{
struct timeval tv;
if (gettimeofday(&tv, (struct timezone *)NULL) < 0) {
if (debug)
warnx("unable to get time of day");
return (0L);
}
#define OFFSET ((u_long)25567 * 24*60*60)
return (htonl((long)(tv.tv_sec + OFFSET)));
#undef OFFSET
}
/* ARGSUSED */
void
machtime_dg(s, sep)
int s;
struct servtab *sep;
{
unsigned long result;
struct sockaddr_in sin;
int size;
size = sizeof(sin);
if (recvfrom(s, (char *)&result, sizeof(result), 0,
(struct sockaddr *)&sin, &size) < 0)
return;
if (check_loop(&sin, sep))
return;
result = machtime();
(void) sendto(s, (char *) &result, sizeof(result), 0,
(struct sockaddr *)&sin, sizeof(sin));
}
/* ARGSUSED */
void
machtime_stream(s, sep)
int s;
struct servtab *sep;
{
unsigned long result;
result = machtime();
(void) write(s, (char *) &result, sizeof(result));
}
/*
* Based on TCPMUX.C by Mark K. Lottor November 1988
* sri-nic::ps:<mkl>tcpmux.c
*/
#define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */
#define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1)
static int /* # of characters upto \r,\n or \0 */
getline(fd, buf, len)
int fd;
char *buf;
int len;
{
int count = 0, n;
struct sigaction sa;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
sa.sa_handler = SIG_DFL;
sigaction(SIGALRM, &sa, (struct sigaction *)0);
do {
alarm(10);
n = read(fd, buf, len-count);
alarm(0);
if (n == 0)
return (count);
if (n < 0)
return (-1);
while (--n >= 0) {
if (*buf == '\r' || *buf == '\n' || *buf == '\0')
return (count);
count++;
buf++;
}
} while (count < len);
return (count);
}
struct servtab *
tcpmux(s)
int s;
{
struct servtab *sep;
char service[MAX_SERV_LEN+1];
int len;
/* Get requested service name */
if ((len = getline(s, service, MAX_SERV_LEN)) < 0) {
strwrite(s, "-Error reading service name\r\n");
return (NULL);
}
service[len] = '\0';
if (debug)
warnx("tcpmux: someone wants %s", service);
/*
* Help is a required command, and lists available services,
* one per line.
*/
if (!strcasecmp(service, "help")) {
for (sep = servtab; sep; sep = sep->se_next) {
if (!ISMUX(sep))
continue;
(void)write(s,sep->se_service,strlen(sep->se_service));
strwrite(s, "\r\n");
}
return (NULL);
}
/* Try matching a service in inetd.conf with the request */
for (sep = servtab; sep; sep = sep->se_next) {
if (!ISMUX(sep))
continue;
if (!strcasecmp(service, sep->se_service)) {
if (ISMUXPLUS(sep)) {
strwrite(s, "+Go\r\n");
}
return (sep);
}
}
strwrite(s, "-Service not available\r\n");
return (NULL);
}