3 * $Id: exec.c,v 1.2 1999/10/22 22:46:17 mdw Exp $
5 * Source and target for executable programs
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
14 * `fw' is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * `fw' is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with `fw'; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.2 1999/10/22 22:46:17 mdw
33 * When a non-file endpoint is attached to a file, keep the file endpoint
34 * open until the nonfile is done. This stops socket sources from
35 * resetting their connection limits too early.
37 * Revision 1.1 1999/07/26 23:33:32 mdw
38 * New sources and targets.
42 /*----- Header files ------------------------------------------------------*/
55 #include <sys/types.h>
62 # include <sys/resource.h>
66 extern char **environ
;
74 #include <mLib/alloc.h>
75 #include <mLib/dstr.h>
77 #include <mLib/fdflags.h>
78 #include <mLib/report.h>
80 #include <mLib/selbuf.h>
95 /*----- Data structures ---------------------------------------------------*/
97 /* --- Resource usage --- */
101 typedef struct xlimit
{
102 #define R(r, n) struct rlimit n;
108 /* --- Environment variable modifications --- */
110 typedef struct xenv
{
120 /* --- Program options --- */
122 typedef struct xopts
{
131 #ifdef HAVE_SETRLIMIT
138 /* --- Executable program arguments --- */
140 typedef struct xargs
{
146 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
148 /* --- Executable endpoints --- */
150 typedef struct xept
{
152 struct xept
*next
, *prev
;
162 #define XEF_CLOSE 16u
165 /* --- Executable program data --- */
167 typedef struct xdata
{
172 /* --- Executable source block --- */
174 typedef struct xsource
{
179 /* --- Executable target block --- */
181 typedef struct xtarget
{
186 /*----- Static variables --------------------------------------------------*/
188 static xopts exec_opts
= { 1, 0, 0, 0, -1, -1, 0, &exec_opts
.env
};
189 static xept
*xept_list
;
191 static sym_table env
;
193 /*----- Fiddling about with resource limits -------------------------------*/
195 #ifdef HAVE_SETRLIMIT
197 /* --- Table mapping user-level names to OS interface bits --- */
199 typedef struct rlimit_ent
{
206 static rlimit_ent rlimits
[] = {
207 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
212 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
214 /* --- @rlimit_get@ --- *
216 * Arguments: @xlimit *xl@ = pointer to limit structure
220 * Use: Initializes a limit structure from the current limits.
223 static void rlimit_get(xlimit
*xl
)
227 for (r
= rlimits
; r
->name
; r
++) {
228 if (getrlimit(r
->r
, RLIMIT(xl
, r
->off
))) {
229 moan("couldn't read %s: %s", r
->rname
, strerror(errno
));
235 /* --- @rlimit_set@ --- *
237 * Arguments: @xlimit *xl@ = pointer to limit structure
241 * Use: Sets resource limits from the supplied limits structure.
244 static void rlimit_set(xlimit
*xl
)
248 for (r
= rlimits
; r
->name
; r
++) {
249 if (setrlimit(r
->r
, RLIMIT(xl
, r
->off
))) {
250 moan("couldn't set %s: %s", r
->rname
, strerror(errno
));
256 /* --- @rlimit_option@ --- */
258 static int rlimit_option(xlimit
*xl
, scanner
*sc
)
260 CONF_BEGIN(sc
, "rlimit", "resource limit")
261 enum { w_soft
, w_hard
, w_both
} which
= w_both
;
266 /* --- Find out which resource is being fiddled --- */
272 for (r
= rlimits
; r
->name
; r
++) {
273 if (strncmp(sc
->d
.buf
, r
->name
, sc
->d
.len
) == 0) {
274 if (r
->name
[sc
->d
.len
] == 0) {
278 error(sc
, "ambiguous resource limit name `%s'", sc
->d
.buf
);
286 rl
= RLIMIT(xl
, chosen
->off
);
289 /* --- Look for hard or soft restrictions --- */
295 if (sc
->t
== CTOK_WORD
) {
296 if ((i
= conf_enum(sc
, "soft,hard",
297 ENUM_ABBREV
| ENUM_NONE
, "limit type")) != -1)
302 /* --- Now read the new value --- */
306 if (sc
->t
!= CTOK_WORD
)
307 error(sc
, "parse error, expected limit value");
309 if (conf_enum(sc
, "unlimited,infinity",
310 ENUM_ABBREV
| ENUM_NONE
, "limit value") > -1)
315 v
= strtol(sc
->d
.buf
, &p
, 0);
317 error(sc
, "parse error, invalid limit value `%s'", sc
->d
.buf
);
318 switch (tolower((unsigned char)*p
)) {
320 case 'b': v
*= 512; break;
323 case 'k': v
*= 1024; break;
324 default: error(sc
, "parse error, invalid limit scale `%c'", *p
);
329 /* --- Store the limit value away --- */
337 if (v
> rl
->rlim_max
)
338 error(sc
, "soft limit %l exceeds hard limit %l for %s",
339 v
, rl
->rlim_max
, chosen
->rname
);
344 if (rl
->rlim_cur
> v
)
355 /*----- Environment fiddling ----------------------------------------------*/
357 /* --- @xenv_option@ --- *
359 * Arguments: @xopts *xo@ = pointer to options block
360 * @scanner *sc@ = pointer to scanner
362 * Returns: Nonzero if claimed
364 * Use: Parses environment variable assignments.
367 static int xenv_option(xopts
*xo
, scanner
*sc
)
369 CONF_BEGIN(sc
, "env", "environment")
372 /* --- Unset a variable --- */
374 if (strcmp(sc
->d
.buf
, "unset") == 0) {
376 if (sc
->t
!= CTOK_WORD
)
377 error(sc
, "parse error, expected environment variable name");
379 xe
->name
= xstrdup(sc
->d
.buf
);
386 /* --- Clear the entire environment --- */
388 if (strcmp(sc
->d
.buf
, "clear") == 0) {
395 /* --- Allow `set' to be omitted if there's a prefix --- */
397 if (strcmp(sc
->d
.buf
, "set") == 0)
402 /* --- Set a variable --- */
404 if (sc
->t
!= CTOK_WORD
)
405 error(sc
, "parse error, expected environment variable name");
407 xe
->name
= xstrdup(sc
->d
.buf
);
411 if (sc
->t
!= CTOK_WORD
)
412 error(sc
, "parse error, expected environment variable value");
413 xe
->value
= xstrdup(sc
->d
.buf
);
421 xo
->etail
= &xe
->next
;
424 /* --- Nothing else to try --- */
429 /* --- @xenv_apply@ --- *
431 * Arguments: @xenv *xe@ = pointer to a variable change list
435 * Use: Modifies the environment (in @env@) according to the list.
438 static void xenv_apply(xenv
*xe
)
443 env_put(&env
, xe
->name
, xe
->value
);
454 /* --- @xenv_destroy@ --- *
456 * Arguments: @xenv *xe@ = pointer to a variable change list
460 * Use: Frees the memory used by an environment variable change list.
463 static void xenv_destroy(xenv
*xe
)
475 /*----- Miscellaneous good things -----------------------------------------*/
477 /* --- @x_tidy@ --- *
479 * Arguments: @xargs *xa@ = pointer to an arguments block
480 * @xopts *xo@ = pointer to an options block
484 * Use: Releases a reference to argument and options blocks.
487 static void x_tidy(xargs
*xa
, xopts
*xo
)
495 xenv_destroy(xo
->env
);
500 /*----- Executable endpoints ----------------------------------------------*/
502 /* --- @attach@ --- */
504 static void xept_error(char */
*p*/
, void */
*v*/
);
506 static void xept_attach(endpt
*e
, reffd
*in
, reffd
*out
)
508 xept
*xe
= (xept
*)e
;
512 /* --- Make a pipe for standard error --- */
515 fw_log(-1, "[%s] couldn't create pipe: %s", xe
->desc
, strerror(errno
));
518 fdflags(fd
[0], O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
520 /* --- Fork a child, and handle an error if there was one --- */
522 if ((kid
= fork()) == -1) {
523 fw_log(-1, "[%s] couldn't fork: %s", xe
->desc
, strerror(errno
));
529 /* --- Do the child thing --- */
534 /* --- Fiddle with the file descriptors --- *
536 * Attach the other endpoint's descriptors to standard input and output.
537 * Attach my pipe to standard error. Mark everything as blocking and
538 * not-to-be-closed-on-exec at this end.
542 if (dup2(in
->fd
, STDIN_FILENO
) < 0 ||
543 dup2(out
->fd
, STDOUT_FILENO
) < 0 ||
544 dup2(fd
[1], STDERR_FILENO
) < 0) {
545 moan("couldn't manipulate file descriptors: %s", strerror(errno
));
554 fdflags(STDIN_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
555 fdflags(STDOUT_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
556 fdflags(STDERR_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
558 /* --- First of all set the @chroot@ prison --- */
560 if (xo
->root
&& chroot(xo
->root
)) {
561 moan("couldn't set `%s' as filesystem root: %s",
562 xo
->root
, strerror(errno
));
566 /* --- Now set the current directory --- */
568 if (xo
->dir ?
chdir(xo
->dir
) : xo
->root ?
chdir("/") : 0) {
569 moan("couldn't set `%s' as current directory: %s",
570 xo
->dir ? xo
->dir
: "/", strerror(errno
));
574 /* --- Set the resource limits --- */
576 #ifdef HAVE_SETRLIMIT
580 /* --- Set group id --- */
583 if (setgid(xo
->gid
)) {
584 moan("couldn't set gid %i: %s", xo
->gid
, strerror(errno
));
587 #ifdef HAVE_SETGROUPS
588 if (setgroups(1, &xo
->gid
))
589 moan("warning: couldn't set group list to %i: %s", xo
->gid
,
594 /* --- Set uid --- */
597 if (setuid(xo
->uid
)) {
598 moan("couldn't set uid %i: %s", xo
->uid
, strerror(errno
));
603 /* --- Play with signal dispositions --- */
605 signal(SIGPIPE
, SIG_DFL
);
607 /* --- Fiddle with the environment --- */
609 xenv_apply(exec_opts
.env
);
610 xenv_apply(xe
->xo
->env
);
611 environ
= env_export(&env
);
613 /* --- Run the program --- */
615 execvp(xe
->xa
->file
, xe
->xa
->argv
);
616 moan("couldn't execute `%s': %s", xe
->xa
->file
, strerror(errno
));
620 /* --- The child's done; see to the parent --- */
623 selbuf_init(&xe
->err
, sel
, fd
[0], xept_error
, xe
);
625 xe
->next
= xept_list
;
628 xept_list
->prev
= xe
;
630 if (!(xe
->xo
->f
& XF_NOLOG
))
631 fw_log(-1, "[%s] started with pid %i", xe
->desc
, kid
);
636 /* --- @xept_file@ --- */
638 static void xept_file(endpt
*e
, endpt
*f
)
640 xept
*xe
= (xept
*)e
;
644 /* --- @xept_close@ --- */
646 static void xept_close(endpt
*e
)
648 xept
*xe
= (xept
*)e
;
651 xe
->f
->ops
->close(xe
->f
);
652 x_tidy(xe
->xa
, xe
->xo
);
658 /* --- @xept_destroy@ --- */
660 static void xept_destroy(xept
*xe
)
662 /* --- First emit the news about the process --- */
664 if (xe
->xo
->f
& XF_NOLOG
)
666 else if (WIFEXITED(xe
->st
)) {
667 if (WEXITSTATUS(xe
->st
) == 0)
668 fw_log(-1, "[%s] pid %i exited successfully", xe
->desc
, xe
->kid
);
670 fw_log(-1, "[%s] pid %i failed: status %i",
671 xe
->desc
, xe
->kid
, WEXITSTATUS(xe
->st
));
673 } else if (WIFSIGNALED(xe
->st
)) {
675 #ifdef HAVE_STRSIGNAL
676 s
= strsignal(WTERMSIG(xe
->st
));
677 #elif HAVE__SYS_SIGLIST
678 s
= _sys_siglist
[WTERMSIG(xe
->st
)];
681 sprintf(buf
, "signal %i", WTERMSIG(xe
->st
));
684 fw_log(-1, "[%s] pid %i failed: %s", xe
->desc
, xe
->kid
, s
);
686 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe
->desc
, xe
->kid
);
688 /* --- Free up the parent-side resources --- */
691 xe
->next
->prev
= xe
->prev
;
693 xe
->prev
->next
= xe
->next
;
695 xept_list
= xe
->next
;
698 xe
->f
->ops
->close(xe
->f
);
699 x_tidy(xe
->xa
, xe
->xo
);
704 /* --- @xept_chld@ --- *
706 * Arguments: @int n@ = signal number
707 * @void *p@ = uninteresting pointer
711 * Use: Deals with child death situations.
714 static void xept_chld(int n
, void *p
)
719 while ((kid
= waitpid(-1, &st
, WNOHANG
)) > 0) {
720 xept
*xe
= xept_list
;
724 if (kid
== xxe
->kid
) {
726 xxe
->e
.f
|= XEF_EXIT
;
727 if (xxe
->e
.f
& XEF_CLOSE
)
735 /* --- @xept_error@ --- *
737 * Arguments: @char *p@ = pointer to string read from stderr
738 * @void *v@ = pointer to by endpoint
742 * Use: Handles error reports from a child process.
745 static void xept_error(char *p
, void *v
)
749 fw_log(-1, "[%s] pid %i: %s", xe
->desc
, xe
->kid
, p
);
751 selbuf_disable(&xe
->err
);
752 close(xe
->err
.reader
.fd
);
753 xe
->e
.f
|= XEF_CLOSE
;
754 if (xe
->e
.f
& XEF_EXIT
)
759 /* --- Endpoint operations --- */
761 static endpt_ops xept_ops
= { xept_attach
, xept_file
, 0, xept_close
};
763 /*----- General operations on sources and targets -------------------------*/
765 /* --- @exec_init@ --- *
771 * Use: Initializes the executable problem source and target.
776 rlimit_get(&exec_opts
.xl
);
777 sig_add(&xept_sig
, SIGCHLD
, xept_chld
, 0);
779 env_import(&env
, environ
);
782 /* --- @exec_option@ --- */
784 static int exec_option(xdata
*x
, scanner
*sc
)
786 xopts
*xo
= x ? x
->xo
: &exec_opts
;
788 CONF_BEGIN(sc
, "exec", "executable");
790 /* --- Logging settings --- */
792 if (strcmp(sc
->d
.buf
, "logging") == 0 ||
793 strcmp(sc
->d
.buf
, "log") == 0) {
797 if (conf_enum(sc
, "no,yes", ENUM_ABBREV
, "logging status"))
804 /* --- Current directory setting --- *
806 * Lots of possibilities to guard against possible brainoes.
809 if (strcmp(sc
->d
.buf
, "dir") == 0 ||
810 strcmp(sc
->d
.buf
, "cd") == 0 ||
811 strcmp(sc
->d
.buf
, "chdir") == 0 ||
812 strcmp(sc
->d
.buf
, "cwd") == 0) {
817 conf_name(sc
, '/', &d
);
818 xo
->dir
= xstrdup(d
.buf
);
823 /* --- Set a chroot prison --- */
825 if (strcmp(sc
->d
.buf
, "root") == 0 ||
826 strcmp(sc
->d
.buf
, "chroot") == 0) {
831 conf_name(sc
, '/', &d
);
832 xo
->root
= xstrdup(d
.buf
);
837 /* --- Set the target user id --- */
839 if (strcmp(sc
->d
.buf
, "uid") == 0 ||
840 strcmp(sc
->d
.buf
, "user") == 0) {
844 if (sc
->t
!= CTOK_WORD
)
845 error(sc
, "parse error, expected user name or uid");
846 if (isdigit((unsigned char)*sc
->d
.buf
))
847 xo
->uid
= atoi(sc
->d
.buf
);
849 struct passwd
*pw
= getpwnam(sc
->d
.buf
);
851 error(sc
, "unknown user name `%s'", sc
->d
.buf
);
852 xo
->uid
= pw
->pw_uid
;
858 /* --- Set the target group id --- */
860 if (strcmp(sc
->d
.buf
, "gid") == 0 ||
861 strcmp(sc
->d
.buf
, "group") == 0) {
865 if (sc
->t
!= CTOK_WORD
)
866 error(sc
, "parse error, expected group name or gid");
867 if (isdigit((unsigned char)*sc
->d
.buf
))
868 xo
->gid
= atoi(sc
->d
.buf
);
870 struct group
*gr
= getgrnam(sc
->d
.buf
);
872 error(sc
, "unknown user name `%s'", sc
->d
.buf
);
873 xo
->gid
= gr
->gr_gid
;
879 /* --- Now try resource limit settings --- */
881 if (rlimit_option(&xo
->xl
, sc
))
884 /* --- And then environment settings --- */
886 if (xenv_option(xo
, sc
))
889 /* --- Nothing found --- */
894 /* --- @exec_desc@ --- */
896 static void exec_desc(xdata
*x
, dstr
*d
)
900 dstr_puts(d
, "exec ");
901 if (strcmp(x
->xa
->file
, x
->xa
->argv
[0]) != 0) {
902 dstr_puts(d
, x
->xa
->file
);
905 for (p
= x
->xa
->argv
; *p
; p
++) {
914 /* --- @exec_read@ --- */
916 static void exec_read(xdata
*x
, scanner
*sc
)
922 /* --- Read the first word --- *
924 * This is either a shell command or the actual program to run.
927 if (sc
->t
== CTOK_WORD
) {
928 dstr_putd(&d
, &sc
->d
); d
.len
++;
933 /* --- See if there's a list of arguments --- *
935 * If not, then the thing I saw was a shell command, so build the proper
936 * arguments for that.
942 error(sc
, "parse error, expected shell command or argument list");
943 xa
= xmalloc(XARGS_SZ(3) + 8 + 3 + d
.len
);
944 p
= (char *)(xa
->argv
+ 4);
947 xa
->argv
[0] = p
; memcpy(p
, "/bin/sh", 8); p
+= 8;
948 xa
->argv
[1] = p
; memcpy(p
, "-c", 3); p
+= 3;
949 xa
->argv
[2] = p
; memcpy(p
, d
.buf
, d
.len
); p
+= d
.len
;
953 /* --- Snarf in a list of arguments --- */
960 /* --- Strip off the leading `[' --- */
964 /* --- Read a sequence of arguments --- */
966 while (sc
->t
== CTOK_WORD
) {
967 dstr_putd(&d
, &sc
->d
); d
.len
++;
972 /* --- Expect the closing `]' --- */
975 error(sc
, "parse error, missing `]'");
978 /* --- If there are no arguments, whinge --- */
981 error(sc
, "must specify at least one argument");
983 /* --- Allocate a lump of memory for the array --- */
985 xa
= xmalloc(XARGS_SZ(argc
) + d
.len
);
988 p
= (char *)(v
+ argc
+ 1);
989 memcpy(p
, d
.buf
, d
.len
);
994 /* --- Start dumping addresses into the @argv@ array --- */
998 while (*p
++ && p
< q
)
1006 /* --- Do some other setting up --- */
1010 x
->xo
= CREATE(xopts
);
1016 /* --- @exec_endpt@ --- */
1018 static endpt
*exec_endpt(xdata
*x
, const char *desc
)
1020 xept
*xe
= CREATE(xept
);
1021 xe
->e
.ops
= &xept_ops
;
1025 xe
->xa
= x
->xa
; xe
->xa
->ref
++;
1026 xe
->xo
= x
->xo
; xe
->xo
->ref
++;
1033 /* --- @exec_destroy@ --- */
1035 static void exec_destroy(xdata
*x
)
1037 x_tidy(x
->xa
, x
->xo
);
1040 /*----- Source definition -------------------------------------------------*/
1042 /* --- @option@ --- */
1044 static int xsource_option(source
*s
, scanner
*sc
)
1046 xsource
*xs
= (xsource
*)s
;
1047 return (exec_option(xs ?
&xs
->x
: 0, sc
));
1050 /* --- @read@ --- */
1052 static source
*xsource_read(scanner
*sc
)
1056 if (!conf_prefix(sc
, "exec"))
1058 xs
= CREATE(xsource
);
1059 xs
->s
.ops
= &xsource_ops
;
1061 exec_read(&xs
->x
, sc
);
1065 /* --- @attach@ --- */
1067 static void xsource_destroy(source */
*s*/
);
1069 static void xsource_attach(source
*s
, scanner
*sc
, target
*t
)
1071 xsource
*xs
= (xsource
*)s
;
1074 /* --- Set up the source description string --- */
1078 exec_desc(&xs
->x
, &d
);
1079 dstr_puts(&d
, " -> ");
1080 dstr_puts(&d
, t
->desc
);
1081 xs
->s
.desc
= xstrdup(d
.buf
);
1085 /* --- Create the endpoints --- */
1087 if ((ee
= t
->ops
->create(t
, xs
->s
.desc
)) == 0)
1089 if ((e
= exec_endpt(&xs
->x
, xs
->s
.desc
)) == 0) {
1095 /* --- Dispose of source and target --- */
1099 xsource_destroy(&xs
->s
);
1102 /* --- @destroy@ --- */
1104 static void xsource_destroy(source
*s
)
1106 xsource
*xs
= (xsource
*)s
;
1107 exec_destroy(&xs
->x
);
1111 /* --- Executable source operations --- */
1113 source_ops xsource_ops
= {
1115 xsource_option
, xsource_read
, xsource_attach
, xsource_destroy
1118 /*----- Exec target description -------------------------------------------*/
1120 /* --- @option@ --- */
1122 static int xtarget_option(target
*t
, scanner
*sc
)
1124 xtarget
*xt
= (xtarget
*)t
;
1125 return (exec_option(xt ?
&xt
->x
: 0, sc
));
1128 /* --- @read@ --- */
1130 static target
*xtarget_read(scanner
*sc
)
1135 if (!conf_prefix(sc
, "exec"))
1137 xt
= CREATE(xtarget
);
1138 xt
->t
.ops
= &xtarget_ops
;
1139 exec_read(&xt
->x
, sc
);
1140 exec_desc(&xt
->x
, &d
);
1141 xt
->t
.desc
= xstrdup(d
.buf
);
1146 /* --- @create@ --- */
1148 static endpt
*xtarget_create(target
*t
, const char *desc
)
1150 xtarget
*xt
= (xtarget
*)t
;
1151 endpt
*e
= exec_endpt(&xt
->x
, desc
);
1155 /* --- @destroy@ --- */
1157 static void xtarget_destroy(target
*t
)
1159 xtarget
*xt
= (xtarget
*)t
;
1160 exec_destroy(&xt
->x
);
1164 /* --- Exec target operations --- */
1166 target_ops xtarget_ops
= {
1168 xtarget_option
, xtarget_read
, xtarget_create
, xtarget_destroy
1171 /*----- That's all, folks -------------------------------------------------*/