e73500d947987b77c5e53bed5d21e496c2adf4f8
3 * $Id: exec.c,v 1.4 2001/02/03 20:30:03 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 1.4 2001/02/03 20:30:03 mdw
33 * Support re-reading config files on SIGHUP.
35 * Revision 1.3 2000/07/01 11:28:52 mdw
36 * Use new mLib selbuf features.
38 * Revision 1.2 1999/10/22 22:46:17 mdw
39 * When a non-file endpoint is attached to a file, keep the file endpoint
40 * open until the nonfile is done. This stops socket sources from
41 * resetting their connection limits too early.
43 * Revision 1.1 1999/07/26 23:33:32 mdw
44 * New sources and targets.
48 /*----- Header files ------------------------------------------------------*/
61 #include <sys/types.h>
68 # include <sys/resource.h>
72 extern char **environ
;
80 #include <mLib/alloc.h>
81 #include <mLib/dstr.h>
83 #include <mLib/fdflags.h>
84 #include <mLib/report.h>
86 #include <mLib/selbuf.h>
101 /*----- Data structures ---------------------------------------------------*/
103 /* --- Resource usage --- */
105 #ifdef HAVE_SETRLIMIT
107 typedef struct xlimit
{
108 #define R(r, n) struct rlimit n;
114 /* --- Environment variable modifications --- */
116 typedef struct xenv
{
126 /* --- Program options --- */
128 typedef struct xopts
{
137 #ifdef HAVE_SETRLIMIT
144 /* --- Executable program arguments --- */
146 typedef struct xargs
{
152 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
154 /* --- Executable endpoints --- */
156 typedef struct xept
{
158 struct xept
*next
, *prev
;
168 #define XEF_CLOSE 16u
171 /* --- Executable program data --- */
173 typedef struct xdata
{
178 /* --- Executable source block --- */
180 typedef struct xsource
{
185 /* --- Executable target block --- */
187 typedef struct xtarget
{
192 /*----- Static variables --------------------------------------------------*/
194 static xopts exec_opts
= { 1, 0, 0, 0, -1, -1, 0, &exec_opts
.env
};
195 static xept
*xept_list
;
197 static sym_table env
;
199 /*----- Fiddling about with resource limits -------------------------------*/
201 #ifdef HAVE_SETRLIMIT
203 /* --- Table mapping user-level names to OS interface bits --- */
205 typedef struct rlimit_ent
{
212 static rlimit_ent rlimits
[] = {
213 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
218 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
220 /* --- @rlimit_get@ --- *
222 * Arguments: @xlimit *xl@ = pointer to limit structure
226 * Use: Initializes a limit structure from the current limits.
229 static void rlimit_get(xlimit
*xl
)
233 for (r
= rlimits
; r
->name
; r
++) {
234 if (getrlimit(r
->r
, RLIMIT(xl
, r
->off
))) {
235 moan("couldn't read %s: %s", r
->rname
, strerror(errno
));
241 /* --- @rlimit_set@ --- *
243 * Arguments: @xlimit *xl@ = pointer to limit structure
247 * Use: Sets resource limits from the supplied limits structure.
250 static void rlimit_set(xlimit
*xl
)
254 for (r
= rlimits
; r
->name
; r
++) {
255 if (setrlimit(r
->r
, RLIMIT(xl
, r
->off
))) {
256 moan("couldn't set %s: %s", r
->rname
, strerror(errno
));
262 /* --- @rlimit_option@ --- */
264 static int rlimit_option(xlimit
*xl
, scanner
*sc
)
266 CONF_BEGIN(sc
, "rlimit", "resource limit")
267 enum { w_soft
, w_hard
, w_both
} which
= w_both
;
272 /* --- Find out which resource is being fiddled --- */
278 for (r
= rlimits
; r
->name
; r
++) {
279 if (strncmp(sc
->d
.buf
, r
->name
, sc
->d
.len
) == 0) {
280 if (r
->name
[sc
->d
.len
] == 0) {
284 error(sc
, "ambiguous resource limit name `%s'", sc
->d
.buf
);
292 rl
= RLIMIT(xl
, chosen
->off
);
295 /* --- Look for hard or soft restrictions --- */
301 if (sc
->t
== CTOK_WORD
) {
302 if ((i
= conf_enum(sc
, "soft,hard",
303 ENUM_ABBREV
| ENUM_NONE
, "limit type")) != -1)
308 /* --- Now read the new value --- */
312 if (sc
->t
!= CTOK_WORD
)
313 error(sc
, "parse error, expected limit value");
315 if (conf_enum(sc
, "unlimited,infinity",
316 ENUM_ABBREV
| ENUM_NONE
, "limit value") > -1)
321 v
= strtol(sc
->d
.buf
, &p
, 0);
323 error(sc
, "parse error, invalid limit value `%s'", sc
->d
.buf
);
324 switch (tolower((unsigned char)*p
)) {
326 case 'b': v
*= 512; break;
329 case 'k': v
*= 1024; break;
330 default: error(sc
, "parse error, invalid limit scale `%c'", *p
);
335 /* --- Store the limit value away --- */
343 if (v
> rl
->rlim_max
)
344 error(sc
, "soft limit %l exceeds hard limit %l for %s",
345 v
, rl
->rlim_max
, chosen
->rname
);
350 if (rl
->rlim_cur
> v
)
361 /*----- Environment fiddling ----------------------------------------------*/
363 /* --- @xenv_option@ --- *
365 * Arguments: @xopts *xo@ = pointer to options block
366 * @scanner *sc@ = pointer to scanner
368 * Returns: Nonzero if claimed
370 * Use: Parses environment variable assignments.
373 static int xenv_option(xopts
*xo
, scanner
*sc
)
375 CONF_BEGIN(sc
, "env", "environment")
378 /* --- Unset a variable --- */
380 if (strcmp(sc
->d
.buf
, "unset") == 0) {
382 if (sc
->t
!= CTOK_WORD
)
383 error(sc
, "parse error, expected environment variable name");
385 xe
->name
= xstrdup(sc
->d
.buf
);
392 /* --- Clear the entire environment --- */
394 if (strcmp(sc
->d
.buf
, "clear") == 0) {
401 /* --- Allow `set' to be omitted if there's a prefix --- */
403 if (strcmp(sc
->d
.buf
, "set") == 0)
408 /* --- Set a variable --- */
410 if (sc
->t
!= CTOK_WORD
)
411 error(sc
, "parse error, expected environment variable name");
413 xe
->name
= xstrdup(sc
->d
.buf
);
417 if (sc
->t
!= CTOK_WORD
)
418 error(sc
, "parse error, expected environment variable value");
419 xe
->value
= xstrdup(sc
->d
.buf
);
427 xo
->etail
= &xe
->next
;
430 /* --- Nothing else to try --- */
435 /* --- @xenv_apply@ --- *
437 * Arguments: @xenv *xe@ = pointer to a variable change list
441 * Use: Modifies the environment (in @env@) according to the list.
444 static void xenv_apply(xenv
*xe
)
449 env_put(&env
, xe
->name
, xe
->value
);
460 /* --- @xenv_destroy@ --- *
462 * Arguments: @xenv *xe@ = pointer to a variable change list
466 * Use: Frees the memory used by an environment variable change list.
469 static void xenv_destroy(xenv
*xe
)
481 /*----- Miscellaneous good things -----------------------------------------*/
483 /* --- @x_tidy@ --- *
485 * Arguments: @xargs *xa@ = pointer to an arguments block
486 * @xopts *xo@ = pointer to an options block
490 * Use: Releases a reference to argument and options blocks.
493 static void x_tidy(xargs
*xa
, xopts
*xo
)
501 xenv_destroy(xo
->env
);
506 /*----- Executable endpoints ----------------------------------------------*/
508 /* --- @attach@ --- */
510 static void xept_error(char */
*p*/
, void */
*v*/
);
512 static void xept_attach(endpt
*e
, reffd
*in
, reffd
*out
)
514 xept
*xe
= (xept
*)e
;
518 /* --- Make a pipe for standard error --- */
521 fw_log(-1, "[%s] couldn't create pipe: %s", xe
->desc
, strerror(errno
));
524 fdflags(fd
[0], O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
526 /* --- Fork a child, and handle an error if there was one --- */
528 if ((kid
= fork()) == -1) {
529 fw_log(-1, "[%s] couldn't fork: %s", xe
->desc
, strerror(errno
));
535 /* --- Do the child thing --- */
540 /* --- Fiddle with the file descriptors --- *
542 * Attach the other endpoint's descriptors to standard input and output.
543 * Attach my pipe to standard error. Mark everything as blocking and
544 * not-to-be-closed-on-exec at this end.
548 if (dup2(in
->fd
, STDIN_FILENO
) < 0 ||
549 dup2(out
->fd
, STDOUT_FILENO
) < 0 ||
550 dup2(fd
[1], STDERR_FILENO
) < 0) {
551 moan("couldn't manipulate file descriptors: %s", strerror(errno
));
560 fdflags(STDIN_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
561 fdflags(STDOUT_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
562 fdflags(STDERR_FILENO
, O_NONBLOCK
, 0, FD_CLOEXEC
, 0);
564 /* --- First of all set the @chroot@ prison --- */
566 if (xo
->root
&& chroot(xo
->root
)) {
567 moan("couldn't set `%s' as filesystem root: %s",
568 xo
->root
, strerror(errno
));
572 /* --- Now set the current directory --- */
574 if (xo
->dir ?
chdir(xo
->dir
) : xo
->root ?
chdir("/") : 0) {
575 moan("couldn't set `%s' as current directory: %s",
576 xo
->dir ? xo
->dir
: "/", strerror(errno
));
580 /* --- Set the resource limits --- */
582 #ifdef HAVE_SETRLIMIT
586 /* --- Set group id --- */
589 if (setgid(xo
->gid
)) {
590 moan("couldn't set gid %i: %s", xo
->gid
, strerror(errno
));
593 #ifdef HAVE_SETGROUPS
594 if (setgroups(1, &xo
->gid
))
595 moan("warning: couldn't set group list to %i: %s", xo
->gid
,
600 /* --- Set uid --- */
603 if (setuid(xo
->uid
)) {
604 moan("couldn't set uid %i: %s", xo
->uid
, strerror(errno
));
609 /* --- Play with signal dispositions --- */
611 signal(SIGPIPE
, SIG_DFL
);
613 /* --- Fiddle with the environment --- */
615 xenv_apply(exec_opts
.env
);
616 xenv_apply(xe
->xo
->env
);
617 environ
= env_export(&env
);
619 /* --- Run the program --- */
621 execvp(xe
->xa
->file
, xe
->xa
->argv
);
622 moan("couldn't execute `%s': %s", xe
->xa
->file
, strerror(errno
));
626 /* --- The child's done; see to the parent --- */
629 selbuf_init(&xe
->err
, sel
, fd
[0], xept_error
, xe
);
631 xe
->next
= xept_list
;
634 xept_list
->prev
= xe
;
636 if (!(xe
->xo
->f
& XF_NOLOG
))
637 fw_log(-1, "[%s] started with pid %i", xe
->desc
, kid
);
642 /* --- @xept_file@ --- */
644 static void xept_file(endpt
*e
, endpt
*f
)
646 xept
*xe
= (xept
*)e
;
650 /* --- @xept_close@ --- */
652 static void xept_close(endpt
*e
)
654 xept
*xe
= (xept
*)e
;
657 xe
->f
->ops
->close(xe
->f
);
658 x_tidy(xe
->xa
, xe
->xo
);
664 /* --- @xept_destroy@ --- */
666 static void xept_destroy(xept
*xe
)
668 /* --- First emit the news about the process --- */
670 if (xe
->xo
->f
& XF_NOLOG
)
672 else if (WIFEXITED(xe
->st
)) {
673 if (WEXITSTATUS(xe
->st
) == 0)
674 fw_log(-1, "[%s] pid %i exited successfully", xe
->desc
, xe
->kid
);
676 fw_log(-1, "[%s] pid %i failed: status %i",
677 xe
->desc
, xe
->kid
, WEXITSTATUS(xe
->st
));
679 } else if (WIFSIGNALED(xe
->st
)) {
681 #ifdef HAVE_STRSIGNAL
682 s
= strsignal(WTERMSIG(xe
->st
));
683 #elif HAVE__SYS_SIGLIST
684 s
= _sys_siglist
[WTERMSIG(xe
->st
)];
687 sprintf(buf
, "signal %i", WTERMSIG(xe
->st
));
690 fw_log(-1, "[%s] pid %i failed: %s", xe
->desc
, xe
->kid
, s
);
692 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe
->desc
, xe
->kid
);
694 /* --- Free up the parent-side resources --- */
697 xe
->next
->prev
= xe
->prev
;
699 xe
->prev
->next
= xe
->next
;
701 xept_list
= xe
->next
;
705 xe
->f
->ops
->close(xe
->f
);
706 x_tidy(xe
->xa
, xe
->xo
);
711 /* --- @xept_chld@ --- *
713 * Arguments: @int n@ = signal number
714 * @void *p@ = uninteresting pointer
718 * Use: Deals with child death situations.
721 static void xept_chld(int n
, void *p
)
726 while ((kid
= waitpid(-1, &st
, WNOHANG
)) > 0) {
727 xept
*xe
= xept_list
;
731 if (kid
== xxe
->kid
) {
733 xxe
->e
.f
|= XEF_EXIT
;
734 if (xxe
->e
.f
& XEF_CLOSE
)
742 /* --- @xept_error@ --- *
744 * Arguments: @char *p@ = pointer to string read from stderr
745 * @void *v@ = pointer to by endpoint
749 * Use: Handles error reports from a child process.
752 static void xept_error(char *p
, void *v
)
756 fw_log(-1, "[%s] pid %i: %s", xe
->desc
, xe
->kid
, p
);
758 close(xe
->err
.reader
.fd
);
759 selbuf_destroy(&xe
->err
);
760 xe
->e
.f
|= XEF_CLOSE
;
761 if (xe
->e
.f
& XEF_EXIT
)
766 /* --- Endpoint operations --- */
768 static endpt_ops xept_ops
= { xept_attach
, xept_file
, 0, xept_close
};
770 /*----- General operations on sources and targets -------------------------*/
772 /* --- @exec_init@ --- *
778 * Use: Initializes the executable problem source and target.
783 rlimit_get(&exec_opts
.xl
);
784 sig_add(&xept_sig
, SIGCHLD
, xept_chld
, 0);
786 env_import(&env
, environ
);
789 /* --- @exec_option@ --- */
791 static int exec_option(xdata
*x
, scanner
*sc
)
793 xopts
*xo
= x ? x
->xo
: &exec_opts
;
795 CONF_BEGIN(sc
, "exec", "executable");
797 /* --- Logging settings --- */
799 if (strcmp(sc
->d
.buf
, "logging") == 0 ||
800 strcmp(sc
->d
.buf
, "log") == 0) {
804 if (conf_enum(sc
, "no,yes", ENUM_ABBREV
, "logging status"))
811 /* --- Current directory setting --- *
813 * Lots of possibilities to guard against possible brainoes.
816 if (strcmp(sc
->d
.buf
, "dir") == 0 ||
817 strcmp(sc
->d
.buf
, "cd") == 0 ||
818 strcmp(sc
->d
.buf
, "chdir") == 0 ||
819 strcmp(sc
->d
.buf
, "cwd") == 0) {
824 conf_name(sc
, '/', &d
);
825 xo
->dir
= xstrdup(d
.buf
);
830 /* --- Set a chroot prison --- */
832 if (strcmp(sc
->d
.buf
, "root") == 0 ||
833 strcmp(sc
->d
.buf
, "chroot") == 0) {
838 conf_name(sc
, '/', &d
);
839 xo
->root
= xstrdup(d
.buf
);
844 /* --- Set the target user id --- */
846 if (strcmp(sc
->d
.buf
, "uid") == 0 ||
847 strcmp(sc
->d
.buf
, "user") == 0) {
851 if (sc
->t
!= CTOK_WORD
)
852 error(sc
, "parse error, expected user name or uid");
853 if (isdigit((unsigned char)*sc
->d
.buf
))
854 xo
->uid
= atoi(sc
->d
.buf
);
856 struct passwd
*pw
= getpwnam(sc
->d
.buf
);
858 error(sc
, "unknown user name `%s'", sc
->d
.buf
);
859 xo
->uid
= pw
->pw_uid
;
865 /* --- Set the target group id --- */
867 if (strcmp(sc
->d
.buf
, "gid") == 0 ||
868 strcmp(sc
->d
.buf
, "group") == 0) {
872 if (sc
->t
!= CTOK_WORD
)
873 error(sc
, "parse error, expected group name or gid");
874 if (isdigit((unsigned char)*sc
->d
.buf
))
875 xo
->gid
= atoi(sc
->d
.buf
);
877 struct group
*gr
= getgrnam(sc
->d
.buf
);
879 error(sc
, "unknown user name `%s'", sc
->d
.buf
);
880 xo
->gid
= gr
->gr_gid
;
886 /* --- Now try resource limit settings --- */
888 if (rlimit_option(&xo
->xl
, sc
))
891 /* --- And then environment settings --- */
893 if (xenv_option(xo
, sc
))
896 /* --- Nothing found --- */
901 /* --- @exec_desc@ --- */
903 static void exec_desc(xdata
*x
, dstr
*d
)
907 dstr_puts(d
, "exec ");
908 if (strcmp(x
->xa
->file
, x
->xa
->argv
[0]) != 0) {
909 dstr_puts(d
, x
->xa
->file
);
912 for (p
= x
->xa
->argv
; *p
; p
++) {
921 /* --- @exec_read@ --- */
923 static void exec_read(xdata
*x
, scanner
*sc
)
929 /* --- Read the first word --- *
931 * This is either a shell command or the actual program to run.
934 if (sc
->t
== CTOK_WORD
) {
935 dstr_putd(&d
, &sc
->d
); d
.len
++;
940 /* --- See if there's a list of arguments --- *
942 * If not, then the thing I saw was a shell command, so build the proper
943 * arguments for that.
949 error(sc
, "parse error, expected shell command or argument list");
950 xa
= xmalloc(XARGS_SZ(3) + 8 + 3 + d
.len
);
951 p
= (char *)(xa
->argv
+ 4);
954 xa
->argv
[0] = p
; memcpy(p
, "/bin/sh", 8); p
+= 8;
955 xa
->argv
[1] = p
; memcpy(p
, "-c", 3); p
+= 3;
956 xa
->argv
[2] = p
; memcpy(p
, d
.buf
, d
.len
); p
+= d
.len
;
960 /* --- Snarf in a list of arguments --- */
967 /* --- Strip off the leading `[' --- */
971 /* --- Read a sequence of arguments --- */
973 while (sc
->t
== CTOK_WORD
) {
974 dstr_putd(&d
, &sc
->d
); d
.len
++;
979 /* --- Expect the closing `]' --- */
982 error(sc
, "parse error, missing `]'");
985 /* --- If there are no arguments, whinge --- */
988 error(sc
, "must specify at least one argument");
990 /* --- Allocate a lump of memory for the array --- */
992 xa
= xmalloc(XARGS_SZ(argc
) + d
.len
);
995 p
= (char *)(v
+ argc
+ 1);
996 memcpy(p
, d
.buf
, d
.len
);
1001 /* --- Start dumping addresses into the @argv@ array --- */
1005 while (*p
++ && p
< q
)
1013 /* --- Do some other setting up --- */
1017 x
->xo
= CREATE(xopts
);
1023 /* --- @exec_endpt@ --- */
1025 static endpt
*exec_endpt(xdata
*x
, const char *desc
)
1027 xept
*xe
= CREATE(xept
);
1028 xe
->e
.ops
= &xept_ops
;
1032 xe
->xa
= x
->xa
; xe
->xa
->ref
++;
1033 xe
->xo
= x
->xo
; xe
->xo
->ref
++;
1036 xe
->desc
= xstrdup(desc
);
1040 /* --- @exec_destroy@ --- */
1042 static void exec_destroy(xdata
*x
)
1044 x_tidy(x
->xa
, x
->xo
);
1047 /*----- Source definition -------------------------------------------------*/
1049 /* --- @option@ --- */
1051 static int xsource_option(source
*s
, scanner
*sc
)
1053 xsource
*xs
= (xsource
*)s
;
1054 return (exec_option(xs ?
&xs
->x
: 0, sc
));
1057 /* --- @read@ --- */
1059 static source
*xsource_read(scanner
*sc
)
1063 if (!conf_prefix(sc
, "exec"))
1065 xs
= CREATE(xsource
);
1066 xs
->s
.ops
= &xsource_ops
;
1068 exec_read(&xs
->x
, sc
);
1072 /* --- @attach@ --- */
1074 static void xsource_destroy(source */
*s*/
);
1076 static void xsource_attach(source
*s
, scanner
*sc
, target
*t
)
1078 xsource
*xs
= (xsource
*)s
;
1081 /* --- Set up the source description string --- */
1085 exec_desc(&xs
->x
, &d
);
1086 dstr_puts(&d
, " -> ");
1087 dstr_puts(&d
, t
->desc
);
1088 xs
->s
.desc
= xstrdup(d
.buf
);
1092 /* --- Create the endpoints --- */
1094 if ((ee
= t
->ops
->create(t
, xs
->s
.desc
)) == 0)
1096 if ((e
= exec_endpt(&xs
->x
, xs
->s
.desc
)) == 0) {
1102 /* --- Dispose of source and target --- */
1106 xsource_destroy(&xs
->s
);
1109 /* --- @destroy@ --- */
1111 static void xsource_destroy(source
*s
)
1113 xsource
*xs
= (xsource
*)s
;
1115 exec_destroy(&xs
->x
);
1119 /* --- Executable source operations --- */
1121 source_ops xsource_ops
= {
1123 xsource_option
, xsource_read
, xsource_attach
, xsource_destroy
1126 /*----- Exec target description -------------------------------------------*/
1128 /* --- @option@ --- */
1130 static int xtarget_option(target
*t
, scanner
*sc
)
1132 xtarget
*xt
= (xtarget
*)t
;
1133 return (exec_option(xt ?
&xt
->x
: 0, sc
));
1136 /* --- @read@ --- */
1138 static target
*xtarget_read(scanner
*sc
)
1143 if (!conf_prefix(sc
, "exec"))
1145 xt
= CREATE(xtarget
);
1146 xt
->t
.ops
= &xtarget_ops
;
1147 exec_read(&xt
->x
, sc
);
1148 exec_desc(&xt
->x
, &d
);
1149 xt
->t
.desc
= xstrdup(d
.buf
);
1154 /* --- @create@ --- */
1156 static endpt
*xtarget_create(target
*t
, const char *desc
)
1158 xtarget
*xt
= (xtarget
*)t
;
1159 endpt
*e
= exec_endpt(&xt
->x
, desc
);
1163 /* --- @destroy@ --- */
1165 static void xtarget_destroy(target
*t
)
1167 xtarget
*xt
= (xtarget
*)t
;
1169 exec_destroy(&xt
->x
);
1173 /* --- Exec target operations --- */
1175 target_ops xtarget_ops
= {
1177 xtarget_option
, xtarget_read
, xtarget_create
, xtarget_destroy
1180 /*----- That's all, folks -------------------------------------------------*/