2 * userv service (or standalone program) for per-user IP subranges.
4 * When invoked appropriately, it creates a point-to-point network
5 * interface with specified parameters. It arranges for packets sent out
6 * via that interface by the kernel to appear on its own stdout in SLIP or
7 * CSLIP encoding, and packets injected into its own stdin to be given to
8 * the kernel as if received on that interface. Optionally, additional
9 * routes can be set up to arrange for traffic for other address ranges to
10 * be routed through the new interface.
12 * This is the service program, which is invoked as root from userv (or may
13 * be invoked firectly).
15 * Its arguments are supposed to be, in order, as follows:
17 * The first two arguments are usually supplied by the userv
18 * configuration. See the file `ipif/ipif' in the source tree, which
19 * is installed in /etc/userv/services.d/ipif by `make install':
23 * Specifies address ranges and gids which own them. The default
24 * configuration supplies /etc/userv/ipif-networks, which is then read
25 * for a list of entries, one per line.
28 * Serves to separate the user-supplied and therefore untrusted
29 * arguments from the trusted first argument.
31 * The remaining arguments are supplied by the (untrusted) caller:
33 * <local-addr>,<peer-addr>,<mtu>,<proto>
35 * As for slattach. Supported protocols are slip, cslip, and
36 * adaptive. Alternatively, set to `debug' to print debugging info
37 * and exit. <local-addr> is address of the interface to be created
38 * on the local system; <peer-addr> is the address of the
39 * point-to-point peer. They must be actual addresses (not
42 * <prefix>/<mask>,<prefix>/<mask>,...
44 * List of additional routes to add for this interface. routes will
45 * be set up on the local system arranging for packets for those
46 * networks to be sent via the created interface. <prefix> must be an
47 * IPv4 address, and mask must be an integer (dotted-quad masks are
48 * not supported). If no additional routes are to be set up, use `-'
49 * or supply an empty argument.
51 * Each <config> item - whether a line file such as
52 * /etc/userv/ipif-networks, or supplied on the service program
53 * command line - is one of:
56 * ./<config-file-name>
57 * ../<config-file-name>
59 * Reads a file which contains lines which are each <config>
62 * <gid>,[=][-|+]<prefix>/<len>(-|+<prefix>/<len>...)[,<junk>]
64 * Indicates that <gid> may allocate addresses in the relevant address
65 * range (<junk> is ignored). <gid> must be numeric. To specify a
66 * single host address, you must specify a mask of /32. If `=' is
67 * specified then the specific subrange is only allowed for the local
68 * endpoint address, but not for remote addresses.
70 * More than one range may be given, with each range prefixed
71 * by + or -. In this case each address range in the rule will
72 * scanned in order, and the first range in the rule that matches
73 * any desired rule will count: if that first matching range is
74 * prefixed by `+' (or nothing) then the rule applies, if it
75 * is prefixed by `-' (or nothing matches), the rule does not.
78 * Means that anything is to be permitted. This should not appear in
79 * /etc/userv/ipif-networks, as that would permit any user on the
80 * system to create any interfaces with any addresses and routes
81 * attached. It is provided so that root can usefully invoke the ipif
82 * service program directly (not via userv), without needing to set up
83 * permissions in /etc/userv/ipif-networks.
87 * Comment. Blank lines are also ignored.
89 * NB: Permission is granted if _any_ config entry matches the request.
91 * The service program should be run from userv with no-disconnect-hup.
94 * Copyright (C) 1999-2000,2003 Ian Jackson
95 * This file is part of ipif, part of userv-utils
97 * This is free software; you can redistribute it and/or modify it
98 * under the terms of the GNU General Public License as published by
99 * the Free Software Foundation; either version 2 of the License, or
100 * (at your option) any later version.
102 * This program is distributed in the hope that it will be useful, but
103 * WITHOUT ANY WARRANTY; without even the implied warranty of
104 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
105 * General Public License for more details.
107 * You should have received a copy of the GNU General Public License
108 * along with userv-utils; if not, write to the Free Software
109 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
125 #include <sys/types.h>
126 #include <sys/wait.h>
127 #include <sys/stat.h>
130 #define MAXEXROUTES 50
133 static const unsigned long gidmaxval
= (unsigned long)((gid_t
)-2);
134 static const char *const protos_ok
[]= { "slip", "cslip", "adaptive", 0 };
135 static const int signals
[]= { SIGHUP
, SIGINT
, SIGTERM
, 0 };
137 static const char *configstr
, *proto
;
138 static unsigned long localaddr
, peeraddr
, mtu
;
139 static int localpming
, peerpming
;
140 static int localallow
, peerallow
, allallow
;
141 static int nexroutes
;
142 static struct exroute
{
143 unsigned long prefix
, mask
;
145 char prefixtxt
[ATXTLEN
], masktxt
[ATXTLEN
];
146 } exroutes
[MAXEXROUTES
];
148 static char localtxt
[ATXTLEN
];
149 static char peertxt
[ATXTLEN
];
151 static struct pplace
{
152 struct pplace
*parent
;
153 const char *filename
;
158 static int slpipe
[2], ptmaster
, undoslattach
;
159 static const char *ifname
;
160 static const char *ptyname
;
165 struct { pid_t sl
, cout
, cin
, task
; } byname
;
166 pid_t bynumber
[NPIDS
];
168 sigset_t emptyset
, fullset
;
171 static int cleantask(void) {
176 if (pid
== (pid_t
)-1)
177 perror("userv-ipif: fork for undo slattach failed - cannot clean up properly");
181 static void terminate(int estatus
) {
185 for (i
=0; i
<NPIDS
; i
++)
186 if (pids
.bynumber
[i
]) kill(pids
.bynumber
[i
], SIGTERM
);
190 execlp("slattach", "slattach", "-p", "tty", ptyname
, (char*)0);
191 perror("userv-ipif: exec slattach for undo slattach failed");
194 if (ifname
&& cleantask()) {
195 execlp("ifconfig", "ifconfig", ifname
, "down", (char*)0);
196 perror("userv-ipif: exec ifconfig for undo ifconfig failed");
202 pid
= waitpid(-1,&status
,0);
203 if (pid
== (pid_t
)-1) break;
209 static void fatal(const char *fmt
, ...)
210 __attribute__((format(printf
,1,2)));
211 static void fatal(const char *fmt
, ...) {
215 fputs("userv-ipif service: fatal error: ",stderr
);
216 vfprintf(stderr
, fmt
, al
);
221 static void sysfatal(const char *fmt
, ...)
222 __attribute__((format(printf
,1,2)));
223 static void sysfatal(const char *fmt
, ...) {
230 fputs("userv-ipif service: fatal system error: ",stderr
);
231 vfprintf(stderr
, fmt
, al
);
232 fprintf(stderr
,": %s\n", strerror(e
));
237 static void badusage(const char *fmt
, ...)
238 __attribute__((format(printf
,1,2)));
239 static void badusage(const char *fmt
, ...) {
245 "userv-ipif service: %s:%d: ",
246 cpplace
->filename
, cpplace
->lineno
);
248 fputs("userv-ipif service: invalid usage: ",stderr
);
251 vfprintf(stderr
, fmt
, al
);
255 for (cpp
=cpplace
->parent
; cpp
; cpp
=cpp
->parent
) {
257 "userv-ipif service: %s:%d: ... in file included from here\n",
258 cpp
->filename
, cpp
->lineno
);
264 static char *ip2txt(unsigned long addr
, char *buf
) {
265 sprintf(buf
, "%lu.%lu.%lu.%lu",
273 static unsigned long eat_number(const char **argp
, const char *what
,
274 unsigned long min
, unsigned long max
,
275 const char *endchars
, int *endchar_r
) {
276 /* If !endchars then the endchar must be a nul, otherwise it may be
277 * a nul (resulting in *argp set to 0) or something else (*argp set
278 * to point to after delim, *endchar_r set to delim).
279 * *endchar_r may be 0.
285 if (!*argp
) { badusage("missing number %s",what
); }
286 rv
= strtoul(*argp
,&ep
,0);
287 if ((endchar
= *ep
)) {
288 if (!endchars
) badusage("junk after number %s",what
);
289 if (!strchr(endchars
,endchar
))
290 badusage("invalid character or delimiter `%c' in or after number, %s:"
291 " expected %s (or none?)", endchar
,what
,endchars
);
296 if (endchar_r
) *endchar_r
= endchar
;
297 if (rv
< min
|| rv
> max
) badusage("number %s value %lu out of range %lu..%lu",
302 static int addrnet_overlap(unsigned long p1
, unsigned long m1
,
303 unsigned long p2
, unsigned long m2
) {
307 return (p1
& mask
) == (p2
& mask
);
310 static void addrnet_mustdiffer(const char *w1
, unsigned long p1
, unsigned long m1
,
311 const char *w2
, unsigned long p2
, unsigned long m2
) {
312 if (!addrnet_overlap(p1
,m1
,p2
,m2
)) return;
313 badusage("%s %08lx/%08lx overlaps/clashes with %s %08lx/%08lx",
317 static unsigned long eat_addr(const char **argp
, const char *what
,
318 const char *endchars
, int *endchar_r
) {
327 sprintf(whatbuf
,"%s byte #%d",what
,i
);
328 rv
|= eat_number(argp
,whatbuf
, 0,255, i
<3 ?
"." : endchars
, endchar_r
);
334 static void eat_prefixmask(const char **argp
, const char *what
,
335 const char *endchars
, int *endchar_r
,
336 unsigned long *prefix_r
, unsigned long *mask_r
, int *len_r
) {
337 /* mask_r and len_r may be 0 */
340 unsigned long prefix
, mask
;
342 prefix
= eat_addr(argp
,what
, "/",0);
343 sprintf(whatbuf
,"%s length",what
);
344 len
= eat_number(argp
,whatbuf
, 0,32, endchars
,endchar_r
);
346 mask
= len ?
(~0UL << (32-len
)) : 0UL;
347 if (prefix
& ~mask
) badusage("%s prefix %08lx not fully contained in mask %08lx",
350 if (mask_r
) *mask_r
= mask
;
351 if (len_r
) *len_r
= len
;
354 static int addrnet_isin(unsigned long prefix
, unsigned long mask
,
355 unsigned long mprefix
, unsigned long mmask
) {
356 return !(~mask
& mmask
) && (prefix
& mmask
) == mprefix
;
359 /* Totally hideous algorithm for parsing the config file lines.
360 * For each config file line, we first see if its gid applies. If not
361 * we skip it. Otherwise, we do
363 * which sets <foo>pming to 1
364 * for each range. <foo>pming may be 0 if we've determined that
365 * this line does not apply to <foo>.
367 * which calls permit_range_thing for each <foo>
368 * which checks to see if <foo> is inside the relevant
369 * range (for +) or overlaps it (for -) and updates
370 * <foo>allow and <foo>pming.
373 static void permit_begin(void) {
376 localpming
= peerpming
= 1;
377 for (i
=0; i
<nexroutes
; i
++) exroutes
[i
].pming
= 1;
380 static void permit_range_thing(unsigned long tprefix
, unsigned long tmask
,
381 const char *what
, int *tallow
, int *tpming
,
382 unsigned long pprefix
, unsigned long pmask
,
383 int plus
, int *any
) {
385 if (!addrnet_isin(tprefix
,tmask
, pprefix
,pmask
)) return;
386 if (*tpming
) *tallow
= 1;
388 if (!addrnet_overlap(tprefix
,tmask
, pprefix
,pmask
)) return;
391 if (!proto
) printf(" %c%s", plus?
'+':'-', what
);
395 static void permit_range(unsigned long prefix
, unsigned long mask
,
396 int plus
, int localonly
) {
400 assert(!(prefix
& ~mask
));
403 permit_range_thing(localaddr
,~0UL,"local", &localallow
,&localpming
,
404 prefix
,mask
, plus
,&any
);
407 permit_range_thing(peeraddr
,~0UL, "peer-addr", &peerallow
,&peerpming
,
408 prefix
,mask
, plus
,&any
);
409 for (i
=0; i
<nexroutes
; i
++) {
410 sprintf(idbuf
,"route#%d",i
);
411 permit_range_thing(exroutes
[i
].prefix
,exroutes
[i
].mask
, idbuf
,
412 &exroutes
[i
].allow
,&exroutes
[i
].pming
,
413 prefix
,mask
, plus
,&any
);
417 if (!any
) fputs(" nothing",stdout
);
420 static void pconfig(const char *configstr
, int truncated
);
422 static void pfile(const char *filename
) {
426 struct pplace npp
, *cpp
;
428 for (cpp
=cpplace
; cpp
; cpp
=cpp
->parent
) {
429 if (!strcmp(cpp
->filename
,filename
))
430 badusage("recursive configuration file `%s'",filename
);
433 file
= fopen(filename
,"r");
435 badusage("cannot open configuration file `%s': %s", filename
, strerror(errno
));
437 if (!proto
) printf("config file `%s':\n",filename
);
440 npp
.filename
= filename
;
444 while (fgets(buf
, sizeof(buf
), file
)) {
449 truncated
= (buf
[l
-1] != '\n');
450 while (l
>0 && isspace((unsigned char) buf
[l
-1])) l
--;
455 while ((c
= getc(file
)) != EOF
&& c
!= '\n');
459 pconfig(buf
,truncated
);
462 badusage("failed while reading configuration file: %s", strerror(errno
));
467 static void pconfig(const char *configstr
, int truncated
) {
468 unsigned long fgid
, tgid
, pprefix
, pmask
;
469 int plen
, localonly
, plus
, rangeix
, delim
;
474 switch (configstr
[0]) {
477 permit_range(0UL,0UL,1,0);
484 if (truncated
) badusage("filename too long (`%.100s...')",configstr
);
489 if (!isdigit((unsigned char)configstr
[0]))
490 badusage("unknown configuration directive");
492 fgid
= eat_number(&configstr
,"gid", 0,gidmaxval
, ",",0);
494 if (!proto
) printf(" %5lu", fgid
);
496 gidlist
= getenv("USERV_GID");
497 if (!gidlist
) fatal("USERV_GID not set");
500 if (!proto
) printf(" no matching gid\n");
503 tgid
= eat_number(&gidlist
,"userv-gid", 0,gidmaxval
, " ",0);
504 if (tgid
== fgid
) break;
507 if (configstr
[0] == '=') {
518 switch (configstr
[0]) {
519 case '-': plus
= 0; /* fall through */
520 case '+': configstr
++;
525 sprintf(whattxt
, "%s-prefix#%d",
526 plus ?
"permitted" : "notpermitted",
528 eat_prefixmask(&configstr
,whattxt
, ",+-",&delim
,
529 &pprefix
,&pmask
,&plen
);
530 if (!configstr
&& truncated
)
531 badusage("gid,prefix/len,... spec too long");
534 printf(" %c%s/%d:", plus?
'+':'-',ip2txt(pprefix
,ptxt
), plen
);
536 permit_range(pprefix
,pmask
,plus
,localonly
);
537 if (delim
==',') break;
539 plus
= delim
=='-' ?
0 : 1;
548 static void checkallow(int allow
, const char *what
,
549 const char *prefixtxt
, const char *masktxt
) {
551 fprintf(stderr
,"userv-ipif service: access denied for %s, %s/%s\n",
552 what
, prefixtxt
, masktxt
);
556 static void parseargs(int argc
, const char *const *argv
) {
557 unsigned long routeaddr
, routemask
;
559 const char *const *cprotop
;
561 char erwhatbuf
[100], erwhatbuf2
[100];
563 if (argc
< NARGS
+1) { badusage("too few arguments"); }
564 if (argc
> NARGS
+1) { badusage("too many arguments"); }
569 if (strcmp(carg
,"--")) badusage("separator argument `--' not found, got `%s'",carg
);
572 localaddr
= eat_addr(&carg
,"local-addr", ",",0);
573 peeraddr
= eat_addr(&carg
,"peer-addr", ",",0);
574 mtu
= eat_number(&carg
,"mtu", 576,65536, ",",0);
575 localallow
= peerallow
= 0;
577 if (!strcmp(carg
,"debug")) {
580 for (cprotop
= protos_ok
;
581 (proto
= *cprotop
) && strcmp(proto
,carg
);
583 if (!proto
) fatal("invalid protocol");
586 addrnet_mustdiffer("local-addr",localaddr
,~0UL, "peer-addr",peeraddr
,~0UL);
589 if (strcmp(carg
,"-")) {
593 if (nexroutes
== MAXEXROUTES
)
594 fatal("too many extra routes (only %d allowed)",MAXEXROUTES
);
595 sprintf(erwhatbuf
,"route#%d",nexroutes
);
597 eat_prefixmask(&carg
,erwhatbuf
, ",",0, &routeaddr
,&routemask
,0);
598 if (routemask
== ~0UL) {
599 addrnet_mustdiffer(erwhatbuf
,routeaddr
,routemask
, "local-addr",localaddr
,~0UL);
600 addrnet_mustdiffer(erwhatbuf
,routeaddr
,routemask
, "peer-addr",peeraddr
,~0UL);
602 for (i
=0; i
<nexroutes
; i
++) {
603 sprintf(erwhatbuf2
,"route#%d",i
);
604 addrnet_mustdiffer(erwhatbuf
,routeaddr
,routemask
,
605 erwhatbuf2
,exroutes
[i
].prefix
,exroutes
[i
].mask
);
607 exroutes
[nexroutes
].prefix
= routeaddr
;
608 exroutes
[nexroutes
].mask
= routemask
;
609 exroutes
[nexroutes
].allow
= 0;
610 ip2txt(routeaddr
,exroutes
[nexroutes
].prefixtxt
);
611 ip2txt(routemask
,exroutes
[nexroutes
].masktxt
);
615 ip2txt(localaddr
,localtxt
);
616 ip2txt(peeraddr
,peertxt
);
619 static void checkpermit(void) {
624 checkallow(localallow
,"local-addr", localtxt
,"32");
625 checkallow(peerallow
,"peer-addr", peertxt
,"32");
626 for (i
=0; i
<nexroutes
; i
++) {
627 sprintf(erwhatbuf
, "route#%d", i
);
628 checkallow(exroutes
[i
].allow
, erwhatbuf
, exroutes
[i
].prefixtxt
, exroutes
[i
].masktxt
);
630 if (!allallow
) fatal("access denied");
633 static void dumpdebug(void) __attribute__((noreturn
));
634 static void dumpdebug(void) {
638 printf("protocol: debug\n"
639 "local: %08lx == %s\n"
640 "peer: %08lx == %s\n"
647 for (i
=0; i
<nexroutes
; i
++) {
648 sprintf(erwhatbuf
, "route#%d:", i
);
649 printf("%-9s %08lx/%08lx == %s/%s\n",
651 exroutes
[i
].prefix
, exroutes
[i
].mask
,
652 exroutes
[i
].prefixtxt
, exroutes
[i
].masktxt
);
654 if (ferror(stdout
) || fclose(stdout
)) sysfatal("flush stdout");
659 static void setsigmask(const sigset_t
*ss
) {
662 r
= sigprocmask(SIG_SETMASK
, ss
, 0);
663 if (r
) sysfatal("[un]block signals");
666 static void setsignals(void (*handler
)(int), struct sigaction
*sa
, int chldflags
) {
670 sa
->sa_handler
= handler
;
672 for (signalp
=signals
; (sig
=*signalp
); signalp
++) {
673 r
= sigaction(sig
, sa
, 0); if (r
) sysfatal("uncatch signal");
675 sa
->sa_flags
= chldflags
;
676 r
= sigaction(SIGCHLD
, sa
, 0); if (r
) sysfatal("uncatch children");
679 static void infork(void) {
682 memset(&pids
,0,sizeof(pids
));
683 sigemptyset(&sa
.sa_mask
);
684 setsignals(SIG_DFL
,&sa
,0);
685 setsigmask(&emptyset
);
689 static pid_t
makesubproc(void (*entry
)(void)) {
692 pid
= fork(); if (pid
== (pid_t
)-1) sysfatal("fork for subprocess");
700 static int task(void) {
704 if (pid
== (pid_t
)-1) sysfatal("fork for task");
705 if (!pid
) { infork(); return 1; }
707 pids
.byname
.task
= pid
;
708 while (pids
.byname
.task
) sigsuspend(&emptyset
);
712 static void mdup2(int fd1
, int fd2
, const char *what
) {
716 r
= dup2(fd1
,fd2
); if (r
==fd2
) return;
717 if (r
!=-1) fatal("dup2 in %s gave wrong answer %d instead of %d",what
,r
,fd2
);
718 if (errno
!= EINTR
) sysfatal("dup2 failed in %s",what
);
722 static void sl_entry(void) {
723 mdup2(slpipe
[1],1,"slattach child");
724 execlp("slattach", "slattach", "-v", "-L", "-p",proto
, ptyname
, (char*)0);
725 sysfatal("cannot exec slattach");
728 static void cin_entry(void) {
729 mdup2(ptmaster
,1,"cat input child");
730 execlp("cat", "cat", (char*)0);
731 sysfatal("cannot exec cat input");
734 static void cout_entry(void) {
735 mdup2(ptmaster
,0,"cat output child");
736 execlp("cat", "cat", (char*)0);
737 sysfatal("cannot exec cat output");
740 static void sighandler(int signum
) {
743 const char *taskfail
;
747 if (signum
== SIGCHLD
) {
749 pid
= waitpid(-1,&status
,WNOHANG
);
750 if (!pid
|| pid
== (pid_t
)-1) return;
752 if (pid
== pids
.byname
.task
) {
756 } else if (pid
== pids
.byname
.cin
) {
759 taskfail
= "input cat";
764 } else if (pid
== pids
.byname
.cout
) {
766 taskfail
= "output cat";
767 } else if (pid
== pids
.byname
.sl
) {
769 taskfail
= "slattach";
776 if (WIFEXITED(status
)) {
778 "userv-ipif service: %s unexpectedly exited with exit status %d\n",
779 taskfail
, WEXITSTATUS(status
));
780 } else if (WIFSIGNALED(status
)) {
782 "userv-ipif service: %s unexpectedly killed by signal %s%s\n",
783 taskfail
, strsignal(WTERMSIG(status
)),
784 WCOREDUMP(status
) ?
" (core dumped)" : "");
786 fprintf(stderr
, "userv-ipif service: %s unexpectedly terminated"
787 " with unknown status code %d\n", taskfail
, status
);
792 "userv-ipif service: received signal %d, terminating\n",
799 static void startup(void) {
803 sigfillset(&fullset
);
804 sigemptyset(&emptyset
);
806 ptmaster
= getpt(); if (ptmaster
==-1) sysfatal("allocate pty master");
807 r
= grantpt(ptmaster
); if (r
) sysfatal("grab/grant pty slave");
808 ptyname
= ptsname(ptmaster
); if (!ptyname
) sysfatal("get pty slave name");
809 r
= chmod(ptyname
,0600); if (r
) sysfatal("chmod pty slave");
810 r
= unlockpt(ptmaster
); if (r
) sysfatal("unlock pty");
812 sigfillset(&sa
.sa_mask
);
813 setsignals(sighandler
,&sa
,SA_NOCLDSTOP
);
814 setsigmask(&fullset
);
817 static void startslattach(void) {
818 static char ifnbuf
[200];
823 r
= pipe(slpipe
); if (r
) sysfatal("create pipe");
824 piper
= fdopen(slpipe
[0],"r"); if (!piper
) sysfatal("fdopen pipe");
827 pids
.byname
.sl
= makesubproc(sl_entry
);
830 setsigmask(&emptyset
);
831 if (!fgets(ifnbuf
,sizeof(ifnbuf
),piper
)) {
832 if (ferror(piper
)) sysfatal("cannot read ifname from slattach");
833 else fatal("cannot read ifname from slattach");
835 setsigmask(&fullset
);
837 if (l
<=0 || ifnbuf
[l
-1] != '\n') fatal("slattach gave strange output `%s'",ifnbuf
);
839 for (k
=l
; k
>0 && ifnbuf
[k
-1]!=' '; k
--);
843 static void netconfigure(void) {
848 sprintf(mtutxt
,"%lu",mtu
);
850 execlp("ifconfig", "ifconfig", ifname
, localtxt
,
851 "netmask","255.255.255.255", "-broadcast", "pointopoint",peertxt
,
852 "mtu",mtutxt
, "up", (char*)0);
853 sysfatal("cannot exec ifconfig");
856 for (i
=0; i
<nexroutes
; i
++) {
858 execlp("route","route", "add", "-net",exroutes
[i
].prefixtxt
,
859 "netmask",exroutes
[i
].masktxt
,
860 "gw",peertxt
, "dev",ifname
, (char*)0);
861 sysfatal("cannot exec route (for route)");
866 static void copydata(void) __attribute__((noreturn
));
867 static void copydata(void) {
870 pids
.byname
.cin
= makesubproc(cin_entry
);
872 r
= write(1, "\300", 1); if (r
==1) break;
873 assert(r
==-1); if (errno
!= EINTR
) sysfatal("send initial delim to confirm");
875 pids
.byname
.cout
= makesubproc(cout_entry
);
877 for (;;) sigsuspend(&emptyset
);
880 int main(int argc
, const char *const *argv
) {
881 parseargs(argc
,argv
);
882 pconfig(configstr
,0);
884 if (!proto
) dumpdebug();