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fakeinetd: attempted ipv6-ization (and it's done)

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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
packed_usage                                       22083   22105     +22
nobodystr                                              4       -      -4
bind_ip_address                                        4       -      -4
ident_substr                                          20       -     -20
chmatch                                               22       -     -22
movefd                                                25       -     -25
skipchars                                             49       -     -49
handlexitsigs                                         51       -     -51
replyError                                            70       -     -70
.rodata                                           158120  158024     -96
deleteConn                                           102       -    -102
G                                                    524     388    -136
conns                                                560       -    -560
fakeidentd_main                                     1457     143   -1314
------------------------------------------------------------------------------
(add/remove: 0/10 grow/shrink: 1/3 up/down: 22/-2453)       Total: -2431 bytes
This commit is contained in:
Denis Vlasenko
2007-01-11 23:26:13 +00:00
parent 4fa5e8b455
commit f8138d1f91
3 changed files with 231 additions and 207 deletions
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49
networking/inetd.c
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@@ -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;