3 * $Id: exec.c,v 1.5 2002/01/13 14:49:03 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 1.5 2002/01/13 14:49:03 mdw
33 * Track @lbuf@ changes in mLib.
35 * Revision 1.4 2001/02/03 20:30:03 mdw
36 * Support re-reading config files on SIGHUP.
38 * Revision 1.3 2000/07/01 11:28:52 mdw
39 * Use new mLib selbuf features.
41 * Revision 1.2 1999/10/22 22:46:17 mdw
42 * When a non-file endpoint is attached to a file, keep the file endpoint
43 * open until the nonfile is done. This stops socket sources from
44 * resetting their connection limits too early.
46 * Revision 1.1 1999/07/26 23:33:32 mdw
47 * New sources and targets.
51 /*----- Header files ------------------------------------------------------*/
64 #include <sys/types.h>
71 # include <sys/resource.h>
75 extern char **environ;
83 #include <mLib/alloc.h>
84 #include <mLib/dstr.h>
86 #include <mLib/fdflags.h>
87 #include <mLib/report.h>
89 #include <mLib/selbuf.h>
104 /*----- Data structures ---------------------------------------------------*/
106 /* --- Resource usage --- */
108 #ifdef HAVE_SETRLIMIT
110 typedef struct xlimit {
111 #define R(r, n) struct rlimit n;
117 /* --- Environment variable modifications --- */
119 typedef struct xenv {
129 /* --- Program options --- */
131 typedef struct xopts {
140 #ifdef HAVE_SETRLIMIT
147 /* --- Executable program arguments --- */
149 typedef struct xargs {
155 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
157 /* --- Executable endpoints --- */
159 typedef struct xept {
161 struct xept *next, *prev;
171 #define XEF_CLOSE 16u
174 /* --- Executable program data --- */
176 typedef struct xdata {
181 /* --- Executable source block --- */
183 typedef struct xsource {
188 /* --- Executable target block --- */
190 typedef struct xtarget {
195 /*----- Static variables --------------------------------------------------*/
197 static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env };
198 static xept *xept_list;
200 static sym_table env;
202 /*----- Fiddling about with resource limits -------------------------------*/
204 #ifdef HAVE_SETRLIMIT
206 /* --- Table mapping user-level names to OS interface bits --- */
208 typedef struct rlimit_ent {
215 static rlimit_ent rlimits[] = {
216 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
221 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
223 /* --- @rlimit_get@ --- *
225 * Arguments: @xlimit *xl@ = pointer to limit structure
229 * Use: Initializes a limit structure from the current limits.
232 static void rlimit_get(xlimit *xl)
236 for (r = rlimits; r->name; r++) {
237 if (getrlimit(r->r, RLIMIT(xl, r->off))) {
238 moan("couldn't read %s: %s", r->rname, strerror(errno));
244 /* --- @rlimit_set@ --- *
246 * Arguments: @xlimit *xl@ = pointer to limit structure
250 * Use: Sets resource limits from the supplied limits structure.
253 static void rlimit_set(xlimit *xl)
257 for (r = rlimits; r->name; r++) {
258 if (setrlimit(r->r, RLIMIT(xl, r->off))) {
259 moan("couldn't set %s: %s", r->rname, strerror(errno));
265 /* --- @rlimit_option@ --- */
267 static int rlimit_option(xlimit *xl, scanner *sc)
269 CONF_BEGIN(sc, "rlimit", "resource limit")
270 enum { w_soft, w_hard, w_both } which = w_both;
275 /* --- Find out which resource is being fiddled --- */
281 for (r = rlimits; r->name; r++) {
282 if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) {
283 if (r->name[sc->d.len] == 0) {
287 error(sc, "ambiguous resource limit name `%s'", sc->d.buf);
295 rl = RLIMIT(xl, chosen->off);
298 /* --- Look for hard or soft restrictions --- */
304 if (sc->t == CTOK_WORD) {
305 if ((i = conf_enum(sc, "soft,hard",
306 ENUM_ABBREV | ENUM_NONE, "limit type")) != -1)
311 /* --- Now read the new value --- */
315 if (sc->t != CTOK_WORD)
316 error(sc, "parse error, expected limit value");
318 if (conf_enum(sc, "unlimited,infinity",
319 ENUM_ABBREV | ENUM_NONE, "limit value") > -1)
324 v = strtol(sc->d.buf, &p, 0);
326 error(sc, "parse error, invalid limit value `%s'", sc->d.buf);
327 switch (tolower((unsigned char)*p)) {
329 case 'b': v *= 512; break;
332 case 'k': v *= 1024; break;
333 default: error(sc, "parse error, invalid limit scale `%c'", *p);
338 /* --- Store the limit value away --- */
346 if (v > rl->rlim_max)
347 error(sc, "soft limit %l exceeds hard limit %l for %s",
348 v, rl->rlim_max, chosen->rname);
353 if (rl->rlim_cur > v)
364 /*----- Environment fiddling ----------------------------------------------*/
366 /* --- @xenv_option@ --- *
368 * Arguments: @xopts *xo@ = pointer to options block
369 * @scanner *sc@ = pointer to scanner
371 * Returns: Nonzero if claimed
373 * Use: Parses environment variable assignments.
376 static int xenv_option(xopts *xo, scanner *sc)
378 CONF_BEGIN(sc, "env", "environment")
381 /* --- Unset a variable --- */
383 if (strcmp(sc->d.buf, "unset") == 0) {
385 if (sc->t != CTOK_WORD)
386 error(sc, "parse error, expected environment variable name");
388 xe->name = xstrdup(sc->d.buf);
395 /* --- Clear the entire environment --- */
397 if (strcmp(sc->d.buf, "clear") == 0) {
404 /* --- Allow `set' to be omitted if there's a prefix --- */
406 if (strcmp(sc->d.buf, "set") == 0)
411 /* --- Set a variable --- */
413 if (sc->t != CTOK_WORD)
414 error(sc, "parse error, expected environment variable name");
416 xe->name = xstrdup(sc->d.buf);
420 if (sc->t != CTOK_WORD)
421 error(sc, "parse error, expected environment variable value");
422 xe->value = xstrdup(sc->d.buf);
430 xo->etail = &xe->next;
433 /* --- Nothing else to try --- */
438 /* --- @xenv_apply@ --- *
440 * Arguments: @xenv *xe@ = pointer to a variable change list
444 * Use: Modifies the environment (in @env@) according to the list.
447 static void xenv_apply(xenv *xe)
452 env_put(&env, xe->name, xe->value);
463 /* --- @xenv_destroy@ --- *
465 * Arguments: @xenv *xe@ = pointer to a variable change list
469 * Use: Frees the memory used by an environment variable change list.
472 static void xenv_destroy(xenv *xe)
484 /*----- Miscellaneous good things -----------------------------------------*/
486 /* --- @x_tidy@ --- *
488 * Arguments: @xargs *xa@ = pointer to an arguments block
489 * @xopts *xo@ = pointer to an options block
493 * Use: Releases a reference to argument and options blocks.
496 static void x_tidy(xargs *xa, xopts *xo)
504 xenv_destroy(xo->env);
509 /*----- Executable endpoints ----------------------------------------------*/
511 /* --- @attach@ --- */
513 static void xept_error(char */*p*/, size_t /*len*/, void */*v*/);
515 static void xept_attach(endpt *e, reffd *in, reffd *out)
517 xept *xe = (xept *)e;
521 /* --- Make a pipe for standard error --- */
524 fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno));
527 fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
529 /* --- Fork a child, and handle an error if there was one --- */
531 if ((kid = fork()) == -1) {
532 fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno));
538 /* --- Do the child thing --- */
543 /* --- Fiddle with the file descriptors --- *
545 * Attach the other endpoint's descriptors to standard input and output.
546 * Attach my pipe to standard error. Mark everything as blocking and
547 * not-to-be-closed-on-exec at this end.
551 if (dup2(in->fd, STDIN_FILENO) < 0 ||
552 dup2(out->fd, STDOUT_FILENO) < 0 ||
553 dup2(fd[1], STDERR_FILENO) < 0) {
554 moan("couldn't manipulate file descriptors: %s", strerror(errno));
563 fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
564 fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
565 fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
567 /* --- First of all set the @chroot@ prison --- */
569 if (xo->root && chroot(xo->root)) {
570 moan("couldn't set `%s' as filesystem root: %s",
571 xo->root, strerror(errno));
575 /* --- Now set the current directory --- */
577 if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) {
578 moan("couldn't set `%s' as current directory: %s",
579 xo->dir ? xo->dir : "/", strerror(errno));
583 /* --- Set the resource limits --- */
585 #ifdef HAVE_SETRLIMIT
589 /* --- Set group id --- */
592 if (setgid(xo->gid)) {
593 moan("couldn't set gid %i: %s", xo->gid, strerror(errno));
596 #ifdef HAVE_SETGROUPS
597 if (setgroups(1, &xo->gid))
598 moan("warning: couldn't set group list to %i: %s", xo->gid,
603 /* --- Set uid --- */
606 if (setuid(xo->uid)) {
607 moan("couldn't set uid %i: %s", xo->uid, strerror(errno));
612 /* --- Play with signal dispositions --- */
614 signal(SIGPIPE, SIG_DFL);
616 /* --- Fiddle with the environment --- */
618 xenv_apply(exec_opts.env);
619 xenv_apply(xe->xo->env);
620 environ = env_export(&env);
622 /* --- Run the program --- */
624 execvp(xe->xa->file, xe->xa->argv);
625 moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno));
629 /* --- The child's done; see to the parent --- */
632 selbuf_init(&xe->err, sel, fd[0], xept_error, xe);
634 xe->next = xept_list;
637 xept_list->prev = xe;
639 if (!(xe->xo->f & XF_NOLOG))
640 fw_log(-1, "[%s] started with pid %i", xe->desc, kid);
645 /* --- @xept_file@ --- */
647 static void xept_file(endpt *e, endpt *f)
649 xept *xe = (xept *)e;
653 /* --- @xept_close@ --- */
655 static void xept_close(endpt *e)
657 xept *xe = (xept *)e;
660 xe->f->ops->close(xe->f);
661 x_tidy(xe->xa, xe->xo);
667 /* --- @xept_destroy@ --- */
669 static void xept_destroy(xept *xe)
671 /* --- First emit the news about the process --- */
673 if (xe->xo->f & XF_NOLOG)
675 else if (WIFEXITED(xe->st)) {
676 if (WEXITSTATUS(xe->st) == 0)
677 fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid);
679 fw_log(-1, "[%s] pid %i failed: status %i",
680 xe->desc, xe->kid, WEXITSTATUS(xe->st));
682 } else if (WIFSIGNALED(xe->st)) {
684 #ifdef HAVE_STRSIGNAL
685 s = strsignal(WTERMSIG(xe->st));
686 #elif HAVE__SYS_SIGLIST
687 s = _sys_siglist[WTERMSIG(xe->st)];
690 sprintf(buf, "signal %i", WTERMSIG(xe->st));
693 fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s);
695 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid);
697 /* --- Free up the parent-side resources --- */
700 xe->next->prev = xe->prev;
702 xe->prev->next = xe->next;
704 xept_list = xe->next;
708 xe->f->ops->close(xe->f);
709 x_tidy(xe->xa, xe->xo);
714 /* --- @xept_chld@ --- *
716 * Arguments: @int n@ = signal number
717 * @void *p@ = uninteresting pointer
721 * Use: Deals with child death situations.
724 static void xept_chld(int n, void *p)
729 while ((kid = waitpid(-1, &st, WNOHANG)) > 0) {
730 xept *xe = xept_list;
734 if (kid == xxe->kid) {
736 xxe->e.f |= XEF_EXIT;
737 if (xxe->e.f & XEF_CLOSE)
745 /* --- @xept_error@ --- *
747 * Arguments: @char *p@ = pointer to string read from stderr
748 * @size_t len@ = length of the string
749 * @void *v@ = pointer to by endpoint
753 * Use: Handles error reports from a child process.
756 static void xept_error(char *p, size_t len, void *v)
760 fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p);
762 close(xe->err.reader.fd);
763 selbuf_destroy(&xe->err);
764 xe->e.f |= XEF_CLOSE;
765 if (xe->e.f & XEF_EXIT)
770 /* --- Endpoint operations --- */
772 static endpt_ops xept_ops = { xept_attach, xept_file, 0, xept_close };
774 /*----- General operations on sources and targets -------------------------*/
776 /* --- @exec_init@ --- *
782 * Use: Initializes the executable problem source and target.
787 rlimit_get(&exec_opts.xl);
788 sig_add(&xept_sig, SIGCHLD, xept_chld, 0);
790 env_import(&env, environ);
793 /* --- @exec_option@ --- */
795 static int exec_option(xdata *x, scanner *sc)
797 xopts *xo = x ? x->xo : &exec_opts;
799 CONF_BEGIN(sc, "exec", "executable");
801 /* --- Logging settings --- */
803 if (strcmp(sc->d.buf, "logging") == 0 ||
804 strcmp(sc->d.buf, "log") == 0) {
808 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
815 /* --- Current directory setting --- *
817 * Lots of possibilities to guard against possible brainoes.
820 if (strcmp(sc->d.buf, "dir") == 0 ||
821 strcmp(sc->d.buf, "cd") == 0 ||
822 strcmp(sc->d.buf, "chdir") == 0 ||
823 strcmp(sc->d.buf, "cwd") == 0) {
828 conf_name(sc, '/', &d);
829 xo->dir = xstrdup(d.buf);
834 /* --- Set a chroot prison --- */
836 if (strcmp(sc->d.buf, "root") == 0 ||
837 strcmp(sc->d.buf, "chroot") == 0) {
842 conf_name(sc, '/', &d);
843 xo->root = xstrdup(d.buf);
848 /* --- Set the target user id --- */
850 if (strcmp(sc->d.buf, "uid") == 0 ||
851 strcmp(sc->d.buf, "user") == 0) {
855 if (sc->t != CTOK_WORD)
856 error(sc, "parse error, expected user name or uid");
857 if (isdigit((unsigned char)*sc->d.buf))
858 xo->uid = atoi(sc->d.buf);
860 struct passwd *pw = getpwnam(sc->d.buf);
862 error(sc, "unknown user name `%s'", sc->d.buf);
863 xo->uid = pw->pw_uid;
869 /* --- Set the target group id --- */
871 if (strcmp(sc->d.buf, "gid") == 0 ||
872 strcmp(sc->d.buf, "group") == 0) {
876 if (sc->t != CTOK_WORD)
877 error(sc, "parse error, expected group name or gid");
878 if (isdigit((unsigned char)*sc->d.buf))
879 xo->gid = atoi(sc->d.buf);
881 struct group *gr = getgrnam(sc->d.buf);
883 error(sc, "unknown user name `%s'", sc->d.buf);
884 xo->gid = gr->gr_gid;
890 /* --- Now try resource limit settings --- */
892 if (rlimit_option(&xo->xl, sc))
895 /* --- And then environment settings --- */
897 if (xenv_option(xo, sc))
900 /* --- Nothing found --- */
905 /* --- @exec_desc@ --- */
907 static void exec_desc(xdata *x, dstr *d)
911 dstr_puts(d, "exec ");
912 if (strcmp(x->xa->file, x->xa->argv[0]) != 0) {
913 dstr_puts(d, x->xa->file);
916 for (p = x->xa->argv; *p; p++) {
925 /* --- @exec_read@ --- */
927 static void exec_read(xdata *x, scanner *sc)
933 /* --- Read the first word --- *
935 * This is either a shell command or the actual program to run.
938 if (sc->t == CTOK_WORD) {
939 dstr_putd(&d, &sc->d); d.len++;
944 /* --- See if there's a list of arguments --- *
946 * If not, then the thing I saw was a shell command, so build the proper
947 * arguments for that.
953 error(sc, "parse error, expected shell command or argument list");
954 xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len);
955 p = (char *)(xa->argv + 4);
958 xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8;
959 xa->argv[1] = p; memcpy(p, "-c", 3); p += 3;
960 xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len;
964 /* --- Snarf in a list of arguments --- */
971 /* --- Strip off the leading `[' --- */
975 /* --- Read a sequence of arguments --- */
977 while (sc->t == CTOK_WORD) {
978 dstr_putd(&d, &sc->d); d.len++;
983 /* --- Expect the closing `]' --- */
986 error(sc, "parse error, missing `]'");
989 /* --- If there are no arguments, whinge --- */
992 error(sc, "must specify at least one argument");
994 /* --- Allocate a lump of memory for the array --- */
996 xa = xmalloc(XARGS_SZ(argc) + d.len);
999 p = (char *)(v + argc + 1);
1000 memcpy(p, d.buf, d.len);
1005 /* --- Start dumping addresses into the @argv@ array --- */
1009 while (*p++ && p < q)
1017 /* --- Do some other setting up --- */
1021 x->xo = CREATE(xopts);
1027 /* --- @exec_endpt@ --- */
1029 static endpt *exec_endpt(xdata *x, const char *desc)
1031 xept *xe = CREATE(xept);
1032 xe->e.ops = &xept_ops;
1036 xe->xa = x->xa; xe->xa->ref++;
1037 xe->xo = x->xo; xe->xo->ref++;
1040 xe->desc = xstrdup(desc);
1044 /* --- @exec_destroy@ --- */
1046 static void exec_destroy(xdata *x)
1048 x_tidy(x->xa, x->xo);
1051 /*----- Source definition -------------------------------------------------*/
1053 /* --- @option@ --- */
1055 static int xsource_option(source *s, scanner *sc)
1057 xsource *xs = (xsource *)s;
1058 return (exec_option(xs ? &xs->x : 0, sc));
1061 /* --- @read@ --- */
1063 static source *xsource_read(scanner *sc)
1067 if (!conf_prefix(sc, "exec"))
1069 xs = CREATE(xsource);
1070 xs->s.ops = &xsource_ops;
1072 exec_read(&xs->x, sc);
1076 /* --- @attach@ --- */
1078 static void xsource_destroy(source */*s*/);
1080 static void xsource_attach(source *s, scanner *sc, target *t)
1082 xsource *xs = (xsource *)s;
1085 /* --- Set up the source description string --- */
1089 exec_desc(&xs->x, &d);
1090 dstr_puts(&d, " -> ");
1091 dstr_puts(&d, t->desc);
1092 xs->s.desc = xstrdup(d.buf);
1096 /* --- Create the endpoints --- */
1098 if ((ee = t->ops->create(t, xs->s.desc)) == 0)
1100 if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) {
1106 /* --- Dispose of source and target --- */
1110 xsource_destroy(&xs->s);
1113 /* --- @destroy@ --- */
1115 static void xsource_destroy(source *s)
1117 xsource *xs = (xsource *)s;
1119 exec_destroy(&xs->x);
1123 /* --- Executable source operations --- */
1125 source_ops xsource_ops = {
1127 xsource_option, xsource_read, xsource_attach, xsource_destroy
1130 /*----- Exec target description -------------------------------------------*/
1132 /* --- @option@ --- */
1134 static int xtarget_option(target *t, scanner *sc)
1136 xtarget *xt = (xtarget *)t;
1137 return (exec_option(xt ? &xt->x : 0, sc));
1140 /* --- @read@ --- */
1142 static target *xtarget_read(scanner *sc)
1147 if (!conf_prefix(sc, "exec"))
1149 xt = CREATE(xtarget);
1150 xt->t.ops = &xtarget_ops;
1151 exec_read(&xt->x, sc);
1152 exec_desc(&xt->x, &d);
1153 xt->t.desc = xstrdup(d.buf);
1158 /* --- @create@ --- */
1160 static endpt *xtarget_create(target *t, const char *desc)
1162 xtarget *xt = (xtarget *)t;
1163 endpt *e = exec_endpt(&xt->x, desc);
1167 /* --- @destroy@ --- */
1169 static void xtarget_destroy(target *t)
1171 xtarget *xt = (xtarget *)t;
1173 exec_destroy(&xt->x);
1177 /* --- Exec target operations --- */
1179 target_ops xtarget_ops = {
1181 xtarget_option, xtarget_read, xtarget_create, xtarget_destroy
1184 /*----- That's all, folks -------------------------------------------------*/