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 .

1 files changed, 505 insertions, 0 deletions

diff --git a/usr.sbin/inetd/builtins.c b/usr.sbin/inetd/builtins.c
new file mode 100644
index 0000000..c4e8973
--- /dev/null
+++ b/usr.sbin/inetd/builtins.c
@@ -0,0 +1,505 @@
+#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);
+}
+