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nc: remove a bit of bloat

Browse Source 
inetd: more NOMMU fixes
rx: shrink
devfsd: minor shrink
vlock: shrink
tcpudp: narrow down window where we have no wildcard socket

parse_one_line                                      1015    1102     +87
init_ring                                              -      53     +53
xzalloc_lsa                                            -      48     +48
read_byte                                             51      50      -1
rearm_alarm                                           28      25      -3
nc_main                                             1028    1000     -28
initring                                              53       -     -53
vlock_main                                           583     496     -87
reread_config_file                                  1089     991     -98
rx_main                                             1046     912    -134
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 1/6 up/down: 188/-404)         Total: -216 bytes
   text    data     bss     dec     hex filename
 800120     661    7428  808209   c5511 busybox_old
 799796     661    7428  807885   c53cd busybox_unstripped
This commit is contained in:
Denis Vlasenko
2008-03-12 23:13:50 +00:00
parent 4e6d5117b8
commit 4cf1d08fc2
7 changed files with 302 additions and 295 deletions
Download Patch File Download Diff File Expand all files Collapse all files

260
networking/inetd.c
View File

@@ -3,6 +3,7 @@
/* $OpenBSD: inetd.c,v 1.79 2001/01/30 08:30:57 deraadt Exp $ */
/* $NetBSD: inetd.c,v 1.11 1996/02/22 11:14:41 mycroft Exp $ */
/* Busybox port by Vladimir Oleynik (C) 2001-2005 <dzo@simtreas.ru> */
/* IPv6 support, many bug fixes by Denys Vlasenko (c) 2008 */
/*
* Copyright (c) 1983,1991 The Regents of the University of California.
* All rights reserved.
@@ -38,21 +39,17 @@
/* Inetd - Internet super-server
*
* This program invokes all internet services as needed.
* connection-oriented services are invoked each time a
* This program invokes configured services when a connection
* from a peer is established or a datagram arrives.
* Connection-oriented services are invoked each time a
* connection is made, by creating a process. This process
* is passed the connection as file descriptor 0 and is
* expected to do a getpeername to find out the source host
* expected to do a getpeername to find out peer's host
* and port.
*
* Datagram oriented services are invoked when a datagram
* 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",
* 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".
* on file descriptor 0. peer's address can be obtained
* using recvfrom.
*
* Inetd uses a configuration file which is read at startup
* and, possibly, at some later time in response to a hangup signal.
@@ -60,28 +57,28 @@
* order shown below. Continuation lines for an entry must begin with
* a space or tab. All fields must be present in each entry.
*
* service name must be in /etc/services
* socket type stream/dgram/raw/rdm/seqpacket
* service_name must be in /etc/services
* socket_type stream/dgram/raw/rdm/seqpacket
* protocol must be in /etc/protocols
* (usually "tcp" or "udp")
* wait/nowait[.max] single-threaded/multi-threaded, max #
* user[.group] or user[:group] user/group to run daemon as
* server program full path name
* server program arguments maximum of MAXARGS (20)
* server_program full path name
* server_program_arguments maximum of MAXARGS (20)
*
* For RPC services
* service name/version must be in /etc/rpc
* socket type stream/dgram/raw/rdm/seqpacket
* service_name/version must be in /etc/rpc
* socket_type stream/dgram/raw/rdm/seqpacket
* rpc/protocol "rpc/tcp" etc
* wait/nowait[.max] single-threaded/multi-threaded
* user[.group] or user[:group] user to run daemon as
* server program full path name
* server program arguments maximum of MAXARGS (20)
* server_program full path name
* server_program_arguments maximum of MAXARGS (20)
*
* For non-RPC services, the "service name" can be of the form
* hostaddress:servicename, in which case the hostaddress is used
* as the host portion of the address to listen on. If hostaddress
* consists of a single `*' character, INADDR_ANY is used.
* consists of a single '*' character, INADDR_ANY is used.
*
* A line can also consist of just
* hostaddress:
@@ -102,7 +99,7 @@
* one line for any given RPC service, even if the host-address
* specifiers are different.
*
* Comment lines are indicated by a `#' in column 1.
* Comment lines are indicated by a '#' in column 1.
*/
/* inetd rules for passing file descriptors to children
@@ -133,6 +130,8 @@
* 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.
*
* In short: "stream" can be "wait" or "nowait"; "dgram" must be "wait".
*/
/* Here's the scoop concerning the user[:group] feature:
@@ -152,26 +151,27 @@
#include <syslog.h>
#include <sys/un.h>
#include "libbb.h"
#if !BB_MMU
/* stream versions of these builtins are forking,
* can't do that (easily) on NOMMU */
#undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 0
#undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
#endif
#include "libbb.h"
#if ENABLE_FEATURE_INETD_RPC
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#endif
#if !BB_MMU
/* stream version of chargen is forking but not execing,
* can't do that (easily) on NOMMU */
#undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
#endif
#define _PATH_INETDPID "/var/run/inetd.pid"
#define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
#define RETRYTIME (60*10) /* retry after bind or server fail */
#define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
#define RETRYTIME 60 /* retry after bind or server fail */
// TODO: explain, or get rid of setrlimit games
#ifndef RLIMIT_NOFILE
#define RLIMIT_NOFILE RLIMIT_OFILE
@@ -209,20 +209,21 @@ typedef struct servtab_t {
#else
#define is_rpc_service(sep) 0
#endif
pid_t se_wait; /* 0:"nowait", 1:"wait" */
pid_t se_wait; /* 0:"nowait", 1:"wait", >1:"wait" */
/* and waiting for this pid */
socktype_t se_socktype; /* SOCK_STREAM/DGRAM/RDM/... */
family_t se_family; /* AF_UNIX/INET[6] */
smallint se_proto_no; /* almost "getprotobyname(se_proto)" */
/* se_proto_no is used by RPC code only... hmm */
smallint se_proto_no; /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
smallint se_checked; /* looked at during merge */
unsigned se_max; /* allowed instances per minute */
unsigned se_count; /* number started since se_time */
unsigned se_time; /* whem we started counting */
char *se_user; /* user name to run as */
char *se_group; /* group name to run as, can be NULL */
#ifdef INETD_BUILTINS_ENABLED
const struct builtin *se_builtin; /* if built-in, description */
#endif
// TODO: wrong algorithm!!!
unsigned se_max; /* max # of instances of this service */
unsigned se_count; /* number started since se_time */
unsigned se_time; /* start of se_count */
struct servtab_t *se_next;
len_and_sockaddr *se_lsa;
char *se_program; /* server program */
@@ -231,60 +232,54 @@ typedef struct servtab_t {
} servtab_t;
#ifdef INETD_BUILTINS_ENABLED
/* Echo received data */
/* Echo received data */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
static void echo_stream(int, servtab_t *);
static void echo_dg(int, servtab_t *);
#endif
/* Internet /dev/null */
/* Internet /dev/null */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
static void discard_stream(int, servtab_t *);
static void discard_dg(int, servtab_t *);
#endif
/* Return 32 bit time since 1900 */
/* Return 32 bit time since 1900 */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
static void machtime_stream(int, servtab_t *);
static void machtime_dg(int, servtab_t *);
#endif
/* Return human-readable time */
/* Return human-readable time */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
static void daytime_stream(int, servtab_t *);
static void daytime_dg(int, servtab_t *);
#endif
/* Familiar character generator */
/* Familiar character generator */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
static void chargen_stream(int, servtab_t *);
static void chargen_dg(int, servtab_t *);
#endif
struct builtin {
const char *bi_service; /* internally provided service name */
uint8_t bi_fork; /* 1 if stream fn should run in child */
/* All builtins are "nowait" */
/* uint8_t bi_wait; */ /* 1 if should wait for child */
/* NB: not necessarily NUL terminated */
char bi_service7[7]; /* internally provided service name */
uint8_t bi_fork; /* 1 if stream fn should run in child */
void (*bi_stream_fn)(int, servtab_t *);
void (*bi_dgram_fn)(int, servtab_t *);
};
static const struct builtin builtins[] = {
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
/* Echo received data */
{ "echo", 1, echo_stream, echo_dg },
#endif
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
/* Internet /dev/null */
{ "discard", 1, discard_stream, discard_dg },
#endif
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
/* Familiar character generator */
{ "chargen", 1, chargen_stream, chargen_dg },
#endif
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
/* Return 32 bit time since 1900 */
{ "time", 0, machtime_stream, machtime_dg },
#endif
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
/* Return human-readable time */
{ "daytime", 0, daytime_stream, daytime_dg },
#endif
};
@@ -305,8 +300,8 @@ struct globals {
FILE *fconfig;
char *default_local_hostname;
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
char *endring;
char *ringpos;
char *end_ring;
char *ring_pos;
char ring[128];
#endif
fd_set allsock;
@@ -333,8 +328,8 @@ struct BUG_G_too_big {
#define default_local_hostname (G.default_local_hostname)
#define first_ps_byte (G.first_ps_byte )
#define last_ps_byte (G.last_ps_byte )
#define endring (G.endring )
#define ringpos (G.ringpos )
#define end_ring (G.end_ring )
#define ring_pos (G.ring_pos )
#define ring (G.ring )
#define allsock (G.allsock )
#define line (G.line )
@@ -357,6 +352,8 @@ static len_and_sockaddr *xzalloc_lsa(int family)
int sz;
sz = sizeof(struct sockaddr_in);
if (family == AF_UNIX)
sz = sizeof(struct sockaddr_un);
#if ENABLE_FEATURE_IPV6
if (family == AF_INET6)
sz = sizeof(struct sockaddr_in6);
@@ -367,7 +364,6 @@ static len_and_sockaddr *xzalloc_lsa(int family)
return lsa;
}
static void rearm_alarm(void)
{
if (!alarm_armed) {
@@ -660,10 +656,8 @@ static NOINLINE servtab_t *parse_one_line(void)
}
arg = next_word(&cp);
if (arg == NULL) {
/* A blank line. */
if (arg == NULL) /* a blank line. */
goto more;
}
/* [host:]service socktype proto wait user[:group] prog [args] */
/* Check for "host:...." line */
@@ -764,9 +758,9 @@ static NOINLINE servtab_t *parse_one_line(void)
}
/* we don't really need getprotobyname()! */
if (strcmp(arg, "tcp") == 0)
sep->se_proto_no = 6;
sep->se_proto_no = IPPROTO_TCP; /* = 6 */
if (strcmp(arg, "udp") == 0)
sep->se_proto_no = 17;
sep->se_proto_no = IPPROTO_UDP; /* = 17 */
if (six)
*six = '6';
if (!sep->se_proto_no) /* not tcp/udp?? */
@@ -785,7 +779,11 @@ static NOINLINE servtab_t *parse_one_line(void)
if (errno)
goto parse_err;
}
sep->se_wait = (strcmp(arg, "wait") == 0);
sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
if (!sep->se_wait) /* "no" seen */
arg += 2;
if (strcmp(arg, "wait") != 0)
goto parse_err;
/* user[:group] prog [args] */
sep->se_user = xstrdup(next_word(&cp));
@@ -804,48 +802,56 @@ static NOINLINE servtab_t *parse_one_line(void)
if (sep->se_program == NULL)
goto parse_err;
#ifdef INETD_BUILTINS_ENABLED
/* sep->se_builtin = NULL; - done by new_servtab() */
if (strcmp(sep->se_program, "internal") == 0
&& strlen(sep->se_service) <= 7
&& (sep->se_socktype == SOCK_STREAM
|| sep->se_socktype == SOCK_DGRAM)
) {
int i;
for (i = 0; i < ARRAY_SIZE(builtins); i++)
if (strcmp(builtins[i].bi_service, sep->se_service) == 0)
if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
goto found_bi;
bb_error_msg("unknown internal service %s", sep->se_service);
goto parse_err;
found_bi:
sep->se_builtin = &builtins[i];
sep->se_wait = 0; /* = builtins[i].bi_wait; - always 0 */
/* stream builtins must be "nowait", dgram must be "wait" */
if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
goto parse_err;
}
#endif
argc = 0;
while ((arg = next_word(&cp)) != NULL && argc < MAXARGV) {
while ((arg = next_word(&cp)) != NULL && argc < MAXARGV)
sep->se_argv[argc++] = xstrdup(arg);
}
/* while (argc <= MAXARGV) */
/* sep->se_argv[argc++] = NULL; - done by new_servtab() */
/*
* Now that we've processed the entire line, check if the hostname
* specifier was a comma separated list of hostnames. If so
* we'll make new entries for each address.
*/
/* catch mixups. "<service> stream udp ..." == wtf */
if (sep->se_socktype == SOCK_STREAM) {
if (sep->se_proto_no == IPPROTO_UDP)
goto parse_err;
}
if (sep->se_socktype == SOCK_DGRAM) {
if (sep->se_proto_no == IPPROTO_TCP)
goto parse_err;
/* "udp nowait" is a small fork bomb :) */
if (!sep->se_wait)
goto parse_err;
}
/* check if the hostname specifier is a comma separated list
* of hostnames. we'll make new entries for each address. */
while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
nsep = dup_servtab(sep);
/*
* NUL terminate the hostname field of the existing entry,
* and make a dup for the new entry.
*/
/* NUL terminate the hostname field of the existing entry,
* and make a dup for the new entry. */
*hostdelim++ = '\0';
nsep->se_local_hostname = xstrdup(hostdelim);
nsep->se_next = sep->se_next;
sep->se_next = nsep;
}
/* Was doing it here: */
/* was doing it here: */
/* DNS resolution, create copies for each IP address */
/* IPv6-ization destroyed it :( */
return sep;
}
@@ -947,15 +953,9 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
switch (sep->se_family) {
struct sockaddr_un *sun;
case AF_UNIX:
/* we have poor infrastructure for AF_UNIX... */
n = strlen(sep->se_service);
if (n > sizeof(sun->sun_path) - 1)
n = sizeof(sun->sun_path) - 1;
lsa = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
lsa->len = sizeof(struct sockaddr_un);
lsa = xzalloc_lsa(AF_UNIX);
sun = (struct sockaddr_un*)&lsa->u.sa;
sun->sun_family = AF_UNIX;
strncpy(sun->sun_path, sep->se_service, n);
safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
break;
default: /* case AF_INET, case AF_INET6 */
@@ -1259,8 +1259,8 @@ int inetd_main(int argc, char **argv)
sep->se_count = 0;
}
}
/* on NOMMU, streamed echo, chargen and discard
* builtins wouldn't work, but they are
/* on NOMMU, streamed chargen
* builtin wouldn't work, but it is
* not allowed on NOMMU (ifdefed out) */
#ifdef INETD_BUILTINS_ENABLED
if (BB_MMU && sep->se_builtin)
@@ -1311,8 +1311,42 @@ int inetd_main(int argc, char **argv)
continue; /* -> check next fd in fd set */
}
#endif
/* child. prepare env and exec program */
/* child */
setsid();
#if 0
/* This does not work.
* Actually, it _almost_ works. The idea behind it is: child
* can peek at (already received and buffered by kernel) UDP packet,
* and perform connect() on the socket so that it is linked only
* to this peer. But this also affects parent, because descriptors
* are shared after fork() a-la dup(). When parent returns to
* select(), it will see this descriptor attached to the peer (!)
* and likely still readable, will act on it and mess things up
* (can create many copies of same child, etc).
* If child will create new socket instead, then bind() and
* connect() it to peer's address, descriptor aliasing problem
* is solved, but first packet cannot be "transferred" to the new
* socket. It is not a problem if child can account for this,
* but our child will exec - and exec'ed program does not know
* about this "lost packet" problem! Pity... */
/* "nowait" udp[6]. Hmmm... */
if (!sep->se_wait
&& sep->se_socktype == SOCK_DGRAM
&& sep->se_family != AF_UNIX
) {
len_and_sockaddr *lsa = xzalloc_lsa(sep->se_family);
/* peek at the packet and remember peer addr */
int r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
&lsa->u.sa, &lsa->len);
if (r >= 0)
/* make this socket "connected" to peer addr:
* only packets from this peer will be recv'ed,
* and bare write()/send() will work on it */
connect(ctrl, &lsa->u.sa, lsa->len);
free(lsa);
}
#endif
/* prepare env and exec program */
pwd = getpwnam(sep->se_user);
if (pwd == NULL) {
bb_error_msg("%s: no such user", sep->se_user);
@@ -1342,8 +1376,8 @@ int inetd_main(int argc, char **argv)
bb_perror_msg("setrlimit");
closelog();
xmove_fd(ctrl, 0);
dup2(0, 1);
dup2(0, 2);
xdup2(0, 1);
xdup2(0, 2);
/* NB: among others, this loop closes listening socket
* for nowait stream children */
for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
@@ -1378,6 +1412,8 @@ static void echo_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
}
#else
static const char *const args[] = { "cat", NULL };
/* no error messages */
xmove_fd(xopen("/dev/null", O_WRONLY), STDERR_FILENO);
BB_EXECVP("cat", (char**)args);
_exit(1);
#endif
@@ -1404,8 +1440,16 @@ static void echo_dg(int s, servtab_t *sep)
/* ARGSUSED */
static void discard_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
{
#if BB_MMU
while (safe_read(s, line, LINE_SIZE) > 0)
continue;
#else
static const char *const args[] = { "dd", "of=/dev/null", NULL };
/* no error messages */
xmove_fd(xopen("/dev/null", O_WRONLY), STDERR_FILENO);
BB_EXECVP("dd", (char**)args);
_exit(1);
#endif
}
/* ARGSUSED */
static void discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
@@ -1418,14 +1462,14 @@ static void discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
#define LINESIZ 72
static void initring(void)
static void init_ring(void)
{
int i;
endring = ring;
end_ring = ring;
for (i = 0; i <= 128; ++i)
if (isprint(i))
*endring++ = i;
*end_ring++ = i;
}
/* Character generator. MMU arches only. */
/* ARGSUSED */
@@ -1435,8 +1479,8 @@ static void chargen_stream(int s, servtab_t *sep)
int len;
char text[LINESIZ + 2];
if (!endring) {
initring();
if (!end_ring) {
init_ring();
rs = ring;
}
@@ -1444,14 +1488,14 @@ static void chargen_stream(int s, servtab_t *sep)
text[LINESIZ + 1] = '\n';
rs = ring;
for (;;) {
len = endring - rs;
len = end_ring - rs;
if (len >= LINESIZ)
memmove(text, rs, LINESIZ);
else {
memmove(text, rs, len);
memmove(text + len, ring, LINESIZ - len);
}
if (++rs == endring)
if (++rs == end_ring)
rs = ring;
xwrite(s, text, sizeof(text));
}
@@ -1469,20 +1513,20 @@ static void chargen_dg(int s, servtab_t *sep)
if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
return;
if (!endring) {
initring();
ringpos = ring;
if (!end_ring) {
init_ring();
ring_pos = ring;
}
len = endring - ringpos;
len = end_ring - ring_pos;
if (len >= LINESIZ)
memmove(text, ringpos, LINESIZ);
memmove(text, ring_pos, LINESIZ);
else {
memmove(text, ringpos, len);
memmove(text, ring_pos, len);
memmove(text + len, ring, LINESIZ - len);
}
if (++ringpos == endring)
ringpos = ring;
if (++ring_pos == end_ring)
ring_pos = ring;
text[LINESIZ] = '\r';
text[LINESIZ + 1] = '\n';
sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
@@ -1498,7 +1542,7 @@ static void chargen_dg(int s, servtab_t *sep)
* we must add 2208988800 seconds to this figure to make up for
* some seventy years Bell Labs was asleep.
*/
static unsigned machtime(void)
static uint32_t machtime(void)
{
struct timeval tv;

7
networking/nc_bloaty.c
View File

@@ -751,6 +751,11 @@ int nc_main(int argc, char **argv)
if (option_mask32 & OPT_s) { /* local address */
/* if o_lport is still 0, then we will use random port */
ouraddr = xhost2sockaddr(str_s, o_lport);
#ifdef BLOAT
/* prevent spurious "UDP listen needs !0 port" */
o_lport = get_nport(ouraddr);
o_lport = ntohs(o_lport);
#endif
x = xsocket(ouraddr->u.sa.sa_family, x, 0);
} else {
/* We try IPv6, then IPv4, unless addr family is
@@ -771,12 +776,14 @@ int nc_main(int argc, char **argv)
setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf);
#endif
#ifdef BLOAT
if (OPT_l && (option_mask32 & (OPT_u|OPT_l)) == (OPT_u|OPT_l)) {
/* apparently UDP can listen ON "port 0",
but that's not useful */
if (!o_lport)
bb_error_msg_and_die("UDP listen needs nonzero -p port");
}
#endif
FD_SET(0, &ding1); /* stdin *is* initially open */
if (proggie) {