f8138d1f9

Denis Vlasenko

2007-01-11

FAILED Duration: 3s

Subject

fakeinetd: attempted ipv6-ization (and it's done) but entire applet can be orders of magnitude smaller if written as an inetd service. So did that (#ifdef'ed out entire old version). inetd version is less than 10% of old one! function old new delta p

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

include/usage.h +9 -0 networking/fakeidentd.c +167 -179 networking/inetd.c +38 -11

include/usage.h+9 -0

@@ -826,6 +826,7 @@
	"\\( and \\) or null; if \\( and \\) are not used, they return the number\n" \
	"of characters matched or 0."

+	#if 0 /* bloaty */
	#define fakeidentd_trivial_usage \
	"[-b ip] [STRING]"
	#define fakeidentd_full_usage \
@@ -833,6 +834,14 @@
	"\n\nOptions:\n" \
	" -b Bind to ip address\n" \
	" STRING The ident answer string (default is nobody)"
+	#else /* inetd-only */
+	#define fakeidentd_trivial_usage \
+	"[username]"
+	#define fakeidentd_full_usage \
+	"Return a (faked) ident response.\n" \
+	"This applet is meant to run from inetd.\n" \
+	"Optional argument is the username to return (default is 'nobody')."
+	#endif

	#define false_trivial_usage \
	""

networking/fakeidentd.c+167 -179

@@ -9,12 +9,62 @@
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

+	/* Ident crash course
+	*
+	* Incoming requests are of form "6191, 23\r\n" - peer asks us
+	* "which user connected from your port 6191 to my port 23?"
+	* We should answer:
+	* "6193, 23 : USERID : UNIX : username\r\n"
+	* and close the connection.
+	* We can also reply:
+	* "6195, 23 : USERID : OTHER[,US-ASCII] : username\r\n"
+	* "6195, 23 : ERROR : INVALID-PORT/NO-USER/HIDDEN-USER/UNKNOWN-ERROR\r\n"
+	* but we probably will never want that.
+	*/
+
	#include "busybox.h"
+
+	#define SANE_INETD_ONLY_VERSION
+
+	#ifdef SANE_INETD_ONLY_VERSION
+
+	int fakeidentd_main(int argc, char **argv)
+	{
+	char buf[64];
+	const char *bogouser = "nobody";
+	char *cur = buf;
+	int rem = sizeof(buf)-1;
+
+	if (argv[1])
+	bogouser = argv[1];
+
+	alarm(30);
+	while (1) {
+	char *p;
+	int sz = safe_read(0, cur, rem);
+	if (sz < 0) return 1;
+	cur[sz] = '\0';
+	p = strpbrk(cur, "\r\n");
+	if (p) {
+	*p = '\0';
+	break;
+	}
+	cur += sz;
+	rem -= sz;
+	if (!rem \|\| !sz)
+	break;
+	}
+	printf("%s : USERID : UNIX : %s\r\n", buf, bogouser);
+	return 0;
+	}
+
+	#else
+
+	/* Welcome to the bloaty horrors */
+
	#include <sys/syslog.h>
	#include <sys/uio.h>

-
-	#define IDENT_PORT 113
	#define MAXCONNS 20
	#define MAXIDLETIME 45

@@ -43,9 +93,9 @@ enum { ident_substr_len = sizeof(ident_substr) - 1 };
	* in `conns' array + FCS
	*/
	static struct {
-	char buf[20];
-	int len;
	time_t lasttime;
+	int len;
+	char buf[20];
	} conns[MAXCONNS];

	/* When using global variables, bind those at least to a structure. */
@@ -55,111 +105,92 @@ static struct {
	int conncnt;
	} G;

-	/*
-	* Prototypes
-	*/
-	static void reply(int s, char *buf);
-	static void replyError(int s, char *buf);
+	static char *bind_ip_address;

-	static const char nobodystr = "nobody"; / this needs to be declared like this */
-	static char *bind_ip_address = "0.0.0.0";
+	static int chmatch(char c, char *chars)
+	{
+	for (; *chars; chars++)
+	if (c == *chars)
+	return 1;
+	return 0;
+	}

-	static void movefd(int from, int to)
+	static int skipchars(char *p, char chars)
	{
-	if (from != to) {
-	dup2(from, to);
-	close(from);
-	}
+	while (chmatch(**p, chars))
+	(*p)++;
+	if (p == '\r' \|\| p == '\n')
+	return 0;
+	return 1;
	}

-	static void inetbind(void)
+	static int parseAddrs(char ptr, char myaddr, char *heraddr)
	{
-	int s, port;
-	struct sockaddr_in addr;
-	int len = sizeof(addr);
-	struct servent *se;
+	/* parse <port-on-server> , <port-on-client> */

-	se = getservbyname("identd", "tcp");
-	port = IDENT_PORT;
-	if (se)
-	port = se->s_port;
+	if (!skipchars(&ptr, " \t"))
+	return -1;

-	s = xsocket(AF_INET, SOCK_STREAM, 0);
+	*myaddr = ptr;

-	setsockopt_reuseaddr(s);
+	if (!skipchars(&ptr, "1234567890"))
+	return -1;

-	memset(&addr, 0, sizeof(addr));
-	addr.sin_addr.s_addr = inet_addr(bind_ip_address);
-	addr.sin_family = AF_INET;
-	addr.sin_port = htons(port);
+	if (!chmatch(*ptr, " \t,"))
+	return -1;

-	xbind(s, (struct sockaddr *)&addr, len);
-	xlisten(s, 5);
+	*ptr++ = '\0';

-	movefd(s, 0);
-	}
+	if (!skipchars(&ptr, " \t,") )
+	return -1;

-	static void handlexitsigs(int signum)
-	{
-	if (unlink(PIDFILE) < 0)
-	close(open(PIDFILE, O_WRONLY\|O_CREAT\|O_TRUNC, 0644));
-	exit(0);
-	}
+	*heraddr = ptr;

-	/* May succeed. If not, won't care. */
-	static void writepid(uid_t nobody, uid_t nogrp)
-	{
-	char buf[sizeof(int)*3 + 2];
-	int fd = open(PIDFILE, O_WRONLY\|O_CREAT\|O_TRUNC, 0664);
+	skipchars(&ptr, "1234567890");

-	if (fd < 0)
-	return;
+	if (!chmatch(*ptr, " \n\r"))
+	return -1;

-	sprintf(buf, "%d\n", getpid());
-	write(fd, buf, strlen(buf));
-	fchown(fd, nobody, nogrp);
-	close(fd);
+	*ptr = '\0';

-	/* should this handle ILL, ... (see signal(7)) */
-	signal(SIGTERM, handlexitsigs);
-	signal(SIGINT, handlexitsigs);
-	signal(SIGQUIT, handlexitsigs);
+	return 0;
	}

-	/* return 0 as parent, 1 as child */
-	static int godaemon(void)
+	static void replyError(int s, char *buf)
	{
-	uid_t nobody, nogrp;
-	struct passwd *pw;
-
-	switch (fork()) {
-	case -1:
-	bb_perror_msg_and_die("fork");
-
-	case 0:
-	pw = getpwnam(nobodystr);
-	if (pw == NULL)
-	bb_error_msg_and_die("cannot find uid/gid of user '%s'", nobodystr);
-	nobody = pw->pw_uid;
-	nogrp = pw->pw_gid;
-	writepid(nobody, nogrp);
-
-	close(0);
-	inetbind();
-	xsetgid(nogrp);
-	xsetuid(nobody);
-	close(1);
-	close(2);
+	struct iovec iv[3];
+	iv[0].iov_base = "0, 0 : ERROR : "; iv[0].iov_len = 15;
+	iv[1].iov_base = buf; iv[1].iov_len = strlen(buf);
+	iv[2].iov_base = "\r\n"; iv[2].iov_len = 2;
+	writev(s, iv, 3);
+	}

-	signal(SIGHUP, SIG_IGN);
-	signal(SIGPIPE, SIG_IGN); /* connection closed when writing (raises ???) */
+	static void reply(int s, char *buf)
+	{
+	char myaddr, heraddr;

-	setsid();
+	myaddr = heraddr = NULL;

-	return 1;
+	if (parseAddrs(buf, &myaddr, &heraddr))
+	replyError(s, "X-INVALID-REQUEST");
+	else {
+	struct iovec iv[6];
+	iv[0].iov_base = myaddr; iv[0].iov_len = strlen(myaddr);
+	iv[1].iov_base = ", "; iv[1].iov_len = 2;
+	iv[2].iov_base = heraddr; iv[2].iov_len = strlen(heraddr);
+	iv[3].iov_base = (void *)ident_substr; iv[3].iov_len = ident_substr_len;
+	iv[4].iov_base = (void *)G.identuser; iv[4].iov_len = strlen(G.identuser);
+	iv[5].iov_base = "\r\n"; iv[5].iov_len = 2;
+	writev(s, iv, 6);
	}
+	}

-	return 0;
+	static void movefd(int from, int to)
+	{
+	if (from != to) {
+	dup2(from, to);
+	close(from);
+	}
	}

	static void deleteConn(int s)
@@ -215,15 +246,32 @@ static int checkInput(char *buf, int len, int l)
	return 0;
	}

+	/* May succeed. If not, won't care. */
+	static const char *to_unlink;
+	static void writepid(void)
+	{
+	int fd = open(PIDFILE, O_WRONLY\|O_CREAT\|O_TRUNC, 0664);
+	if (fd < 0)
+	return;
+	to_unlink = PIDFILE;
+	fdprintf(fd, "%d\n", getpid());
+	close(fd);
+	}
+
+	static void handlexitsigs(int signum)
+	{
+	if (to_unlink)
+	if (unlink(to_unlink) < 0)
+	close(open(to_unlink, O_WRONLY\|O_CREAT\|O_TRUNC, 0644));
+	exit(0);
+	}
+
	int fakeidentd_main(int argc, char **argv)
	{
-	/* This applet is an inetd-style daemon */
-	openlog(applet_name, 0, LOG_DAEMON);
-	logmode = LOGMODE_SYSLOG;
+	int fd;
+	pid_t pid;

-	memset(conns, 0, sizeof(conns));
-	memset(&G, 0, sizeof(G));
-	FD_ZERO(&G.readfds);
+	/* FD_ZERO(&G.readfds); - in bss, already zeroed */
	FD_SET(0, &G.readfds);

	/* handle -b <ip> parameter */
@@ -232,11 +280,30 @@ int fakeidentd_main(int argc, char **argv)
	if (optind < argc)
	G.identuser = argv[optind];
	else
-	G.identuser = nobodystr;
+	G.identuser = "nobody";

-	/* daemonize and have the parent return */
-	if (godaemon() == 0)
-	return 0;
+	writepid();
+	signal(SIGTERM, handlexitsigs);
+	signal(SIGINT, handlexitsigs);
+	signal(SIGQUIT, handlexitsigs);
+	signal(SIGHUP, SIG_IGN);
+	signal(SIGPIPE, SIG_IGN); /* ignore closed connections when writing */
+
+	fd = create_and_bind_stream_or_die(bind_ip_address, bb_lookup_port("identd", "tcp", 113));
+	xlisten(fd, 5);
+
+	pid = fork();
+	if (pid < 0)
+	bb_perror_msg_and_die("fork");
+	if (pid != 0) /* parent */
+	exit(0);
+	/* child */
+	setsid();
+	movefd(fd, 0);
+	while (fd)
+	close(fd--);
+	openlog(applet_name, 0, LOG_DAEMON);
+	logmode = LOGMODE_SYSLOG;

	/* main loop where we process all events and never exit */
	while (1) {
@@ -252,10 +319,11 @@ int fakeidentd_main(int argc, char **argv)

	if (FD_ISSET(s, &rfds)) {
	char *buf = conns[i].buf;
-	unsigned int len = conns[i].len;
-	unsigned int l;
+	unsigned len = conns[i].len;
+	unsigned l;

-	if ((l = read(s, buf + len, sizeof(conns[0].buf) - len)) > 0) {
+	l = read(s, buf + len, sizeof(conns[0].buf) - len);
+	if (l > 0) {
	if (checkInput(buf, len, l)) {
	reply(s, buf);
	goto deleteconn;
@@ -268,10 +336,8 @@ int fakeidentd_main(int argc, char **argv)
	} else {
	goto deleteconn;
	}
-
	conns[i].lasttime = tim;
	continue;
-
	deleteconn:
	deleteConn(s);
	} else {
@@ -287,7 +353,7 @@ deleteconn:
	int s = accept(0, NULL, 0);

	if (s < 0) {
-	if (errno != EINTR) /* EINTR */
+	if (errno != EINTR)
	bb_perror_msg("accept");
	} else {
	if (G.conncnt == MAXCONNS)
@@ -297,7 +363,6 @@ deleteconn:

	movefd(s, i + FCS); /* move if not already there */
	FD_SET(i + FCS, &G.readfds);
-
	conns[i].len = 0;
	conns[i].lasttime = time(NULL);
	}
@@ -307,81 +372,4 @@ deleteconn:
	return 0;
	}

-	static int parseAddrs(char ptr, char myaddr, char *heraddr);
-	static void reply(int s, char *buf)
-	{
-	char myaddr, heraddr;
-
-	myaddr = heraddr = NULL;
-
-	if (parseAddrs(buf, &myaddr, &heraddr))
-	replyError(s, "X-INVALID-REQUEST");
-	else {
-	struct iovec iv[6];
-	iv[0].iov_base = myaddr; iv[0].iov_len = strlen(myaddr);
-	iv[1].iov_base = ", "; iv[1].iov_len = 2;
-	iv[2].iov_base = heraddr; iv[2].iov_len = strlen(heraddr);
-	iv[3].iov_base = (void *)ident_substr; iv[3].iov_len = ident_substr_len;
-	iv[4].iov_base = (void *)G.identuser; iv[4].iov_len = strlen(G.identuser);
-	iv[5].iov_base = "\r\n"; iv[5].iov_len = 2;
-	writev(s, iv, 6);
-	}
-	}
-
-	static void replyError(int s, char *buf)
-	{
-	struct iovec iv[3];
-	iv[0].iov_base = "0, 0 : ERROR : "; iv[0].iov_len = 15;
-	iv[1].iov_base = buf; iv[1].iov_len = strlen(buf);
-	iv[2].iov_base = "\r\n"; iv[2].iov_len = 2;
-	writev(s, iv, 3);
-	}
-
-	static int chmatch(char c, char *chars)
-	{
-	for (; *chars; chars++)
-	if (c == *chars)
-	return 1;
-	return 0;
-	}
-
-	static int skipchars(char *p, char chars)
-	{
-	while (chmatch(**p, chars))
-	(*p)++;
-	if (p == '\r' \|\| p == '\n')
-	return 0;
-	return 1;
-	}
-
-	static int parseAddrs(char ptr, char myaddr, char *heraddr)
-	{
-	/* parse <port-on-server> , <port-on-client> */
-
-	if (!skipchars(&ptr, " \t"))
-	return -1;
-
-	*myaddr = ptr;
-
-	if (!skipchars(&ptr, "1234567890"))
-	return -1;
-
-	if (!chmatch(*ptr, " \t,"))
-	return -1;
-
-	*ptr++ = '\0';
-
-	if (!skipchars(&ptr, " \t,") )
-	return -1;
-
-	*heraddr = ptr;
-
-	skipchars(&ptr, "1234567890");
-
-	if (!chmatch(*ptr, " \n\r"))
-	return -1;
-
-	*ptr = '\0';
-
-	return 0;
-	}
+	#endif /* !SANE_INETD_ONLY_VERSION */

networking/inetd.c+38 -11

@@ -23,7 +23,7 @@
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
-	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
@@ -36,8 +36,7 @@
	* SUCH DAMAGE.
	*/

-	/*
-	* Inetd - Internet super-server
+	/* Inetd - Internet super-server
	*
	* This program invokes all internet services as needed.
	* connection-oriented services are invoked each time a
@@ -50,14 +49,14 @@
	* arrives; a process is created and passed a pending message
	* on file descriptor 0. Datagram servers may either connect
	* to their peer, freeing up the original socket for inetd
-	* to receive further messages on, or ``take over the socket'',
+	* to receive further messages on, or "take over the socket",
	* processing all arriving datagrams and, eventually, timing
-	* out. The first type of server is said to be ``multi-threaded'';
-	* the second type of server ``single-threaded''.
+	* out. The first type of server is said to be "multi-threaded";
+	* the second type of server "single-threaded".
	*
	* Inetd uses a configuration file which is read at startup
	* and, possibly, at some later time in response to a hangup signal.
-	* The configuration file is ``free format'' with fields given in the
+	* The configuration file is "free format" with fields given in the
	* order shown below. Continuation lines for an entry must begin with
	* a space or tab. All fields must be present in each entry.
	*
@@ -105,8 +104,37 @@
	* Comment lines are indicated by a `#' in column 1.
	*/

-	/*
-	* Here's the scoop concerning the user[.:]group feature:
+	/* inetd rules for passing file descriptors to children
+	* (http://www.freebsd.org/cgi/man.cgi?query=inetd):
+	*
+	* The wait/nowait entry specifies whether the server that is invoked by
+	* inetd will take over the socket associated with the service access point,
+	* and thus whether inetd should wait for the server to exit before listen-
+	* ing for new service requests. Datagram servers must use "wait", as
+	* they are always invoked with the original datagram socket bound to the
+	* specified service address. These servers must read at least one datagram
+	* from the socket before exiting. If a datagram server connects to its
+	* peer, freeing the socket so inetd can receive further messages on the
+	* socket, it is said to be a "multi-threaded" server; it should read one
+	* datagram from the socket and create a new socket connected to the peer.
+	* It should fork, and the parent should then exit to allow inetd to check
+	* for new service requests to spawn new servers. Datagram servers which
+	* process all incoming datagrams on a socket and eventually time out are
+	* said to be "single-threaded". The comsat(8), (biff(1)) and talkd(8)
+	* utilities are both examples of the latter type of datagram server. The
+	* tftpd(8) utility is an example of a multi-threaded datagram server.
+	*
+	* Servers using stream sockets generally are multi-threaded and use the
+	* "nowait" entry. Connection requests for these services are accepted by
+	* inetd, and the server is given only the newly-accepted socket connected
+	* to a client of the service. Most stream-based services operate in this
+	* manner. Stream-based servers that use "wait" are started with the lis-
+	* tening service socket, and must accept at least one connection request
+	* before exiting. Such a server would normally accept and process incoming
+	* connection requests until a timeout.
+	*/
+
+	/* Here's the scoop concerning the user[.:]group feature:
	*
	* 1) set-group-option off.
	*
@@ -125,7 +153,6 @@
	* b) other: setgid(specified group)
	* initgroups(name, specified group)
	* setuid()
-	*
	*/

	#include "busybox.h"
@@ -161,7 +188,7 @@
	#endif

	/* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
-	#define FD_MARGIN (8)
+	#define FD_MARGIN 8
	static rlim_t rlim_ofile_cur = OPEN_MAX;
	static struct rlimit rlim_ofile;