3 * $Id: exec.c,v 1.3 2000/07/01 11:28:52 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 1.3 2000/07/01 11:28:52 mdw
33 * Use new mLib selbuf features.
35 * Revision 1.2 1999/10/22 22:46:17 mdw
36 * When a non-file endpoint is attached to a file, keep the file endpoint
37 * open until the nonfile is done. This stops socket sources from
38 * resetting their connection limits too early.
40 * Revision 1.1 1999/07/26 23:33:32 mdw
41 * New sources and targets.
45 /*----- Header files ------------------------------------------------------*/
58 #include <sys/types.h>
65 # include <sys/resource.h>
69 extern char **environ;
77 #include <mLib/alloc.h>
78 #include <mLib/dstr.h>
80 #include <mLib/fdflags.h>
81 #include <mLib/report.h>
83 #include <mLib/selbuf.h>
98 /*----- Data structures ---------------------------------------------------*/
100 /* --- Resource usage --- */
102 #ifdef HAVE_SETRLIMIT
104 typedef struct xlimit {
105 #define R(r, n) struct rlimit n;
111 /* --- Environment variable modifications --- */
113 typedef struct xenv {
123 /* --- Program options --- */
125 typedef struct xopts {
134 #ifdef HAVE_SETRLIMIT
141 /* --- Executable program arguments --- */
143 typedef struct xargs {
149 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
151 /* --- Executable endpoints --- */
153 typedef struct xept {
155 struct xept *next, *prev;
165 #define XEF_CLOSE 16u
168 /* --- Executable program data --- */
170 typedef struct xdata {
175 /* --- Executable source block --- */
177 typedef struct xsource {
182 /* --- Executable target block --- */
184 typedef struct xtarget {
189 /*----- Static variables --------------------------------------------------*/
191 static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env };
192 static xept *xept_list;
194 static sym_table env;
196 /*----- Fiddling about with resource limits -------------------------------*/
198 #ifdef HAVE_SETRLIMIT
200 /* --- Table mapping user-level names to OS interface bits --- */
202 typedef struct rlimit_ent {
209 static rlimit_ent rlimits[] = {
210 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
215 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
217 /* --- @rlimit_get@ --- *
219 * Arguments: @xlimit *xl@ = pointer to limit structure
223 * Use: Initializes a limit structure from the current limits.
226 static void rlimit_get(xlimit *xl)
230 for (r = rlimits; r->name; r++) {
231 if (getrlimit(r->r, RLIMIT(xl, r->off))) {
232 moan("couldn't read %s: %s", r->rname, strerror(errno));
238 /* --- @rlimit_set@ --- *
240 * Arguments: @xlimit *xl@ = pointer to limit structure
244 * Use: Sets resource limits from the supplied limits structure.
247 static void rlimit_set(xlimit *xl)
251 for (r = rlimits; r->name; r++) {
252 if (setrlimit(r->r, RLIMIT(xl, r->off))) {
253 moan("couldn't set %s: %s", r->rname, strerror(errno));
259 /* --- @rlimit_option@ --- */
261 static int rlimit_option(xlimit *xl, scanner *sc)
263 CONF_BEGIN(sc, "rlimit", "resource limit")
264 enum { w_soft, w_hard, w_both } which = w_both;
269 /* --- Find out which resource is being fiddled --- */
275 for (r = rlimits; r->name; r++) {
276 if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) {
277 if (r->name[sc->d.len] == 0) {
281 error(sc, "ambiguous resource limit name `%s'", sc->d.buf);
289 rl = RLIMIT(xl, chosen->off);
292 /* --- Look for hard or soft restrictions --- */
298 if (sc->t == CTOK_WORD) {
299 if ((i = conf_enum(sc, "soft,hard",
300 ENUM_ABBREV | ENUM_NONE, "limit type")) != -1)
305 /* --- Now read the new value --- */
309 if (sc->t != CTOK_WORD)
310 error(sc, "parse error, expected limit value");
312 if (conf_enum(sc, "unlimited,infinity",
313 ENUM_ABBREV | ENUM_NONE, "limit value") > -1)
318 v = strtol(sc->d.buf, &p, 0);
320 error(sc, "parse error, invalid limit value `%s'", sc->d.buf);
321 switch (tolower((unsigned char)*p)) {
323 case 'b': v *= 512; break;
326 case 'k': v *= 1024; break;
327 default: error(sc, "parse error, invalid limit scale `%c'", *p);
332 /* --- Store the limit value away --- */
340 if (v > rl->rlim_max)
341 error(sc, "soft limit %l exceeds hard limit %l for %s",
342 v, rl->rlim_max, chosen->rname);
347 if (rl->rlim_cur > v)
358 /*----- Environment fiddling ----------------------------------------------*/
360 /* --- @xenv_option@ --- *
362 * Arguments: @xopts *xo@ = pointer to options block
363 * @scanner *sc@ = pointer to scanner
365 * Returns: Nonzero if claimed
367 * Use: Parses environment variable assignments.
370 static int xenv_option(xopts *xo, scanner *sc)
372 CONF_BEGIN(sc, "env", "environment")
375 /* --- Unset a variable --- */
377 if (strcmp(sc->d.buf, "unset") == 0) {
379 if (sc->t != CTOK_WORD)
380 error(sc, "parse error, expected environment variable name");
382 xe->name = xstrdup(sc->d.buf);
389 /* --- Clear the entire environment --- */
391 if (strcmp(sc->d.buf, "clear") == 0) {
398 /* --- Allow `set' to be omitted if there's a prefix --- */
400 if (strcmp(sc->d.buf, "set") == 0)
405 /* --- Set a variable --- */
407 if (sc->t != CTOK_WORD)
408 error(sc, "parse error, expected environment variable name");
410 xe->name = xstrdup(sc->d.buf);
414 if (sc->t != CTOK_WORD)
415 error(sc, "parse error, expected environment variable value");
416 xe->value = xstrdup(sc->d.buf);
424 xo->etail = &xe->next;
427 /* --- Nothing else to try --- */
432 /* --- @xenv_apply@ --- *
434 * Arguments: @xenv *xe@ = pointer to a variable change list
438 * Use: Modifies the environment (in @env@) according to the list.
441 static void xenv_apply(xenv *xe)
446 env_put(&env, xe->name, xe->value);
457 /* --- @xenv_destroy@ --- *
459 * Arguments: @xenv *xe@ = pointer to a variable change list
463 * Use: Frees the memory used by an environment variable change list.
466 static void xenv_destroy(xenv *xe)
478 /*----- Miscellaneous good things -----------------------------------------*/
480 /* --- @x_tidy@ --- *
482 * Arguments: @xargs *xa@ = pointer to an arguments block
483 * @xopts *xo@ = pointer to an options block
487 * Use: Releases a reference to argument and options blocks.
490 static void x_tidy(xargs *xa, xopts *xo)
498 xenv_destroy(xo->env);
503 /*----- Executable endpoints ----------------------------------------------*/
505 /* --- @attach@ --- */
507 static void xept_error(char */*p*/, void */*v*/);
509 static void xept_attach(endpt *e, reffd *in, reffd *out)
511 xept *xe = (xept *)e;
515 /* --- Make a pipe for standard error --- */
518 fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno));
521 fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
523 /* --- Fork a child, and handle an error if there was one --- */
525 if ((kid = fork()) == -1) {
526 fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno));
532 /* --- Do the child thing --- */
537 /* --- Fiddle with the file descriptors --- *
539 * Attach the other endpoint's descriptors to standard input and output.
540 * Attach my pipe to standard error. Mark everything as blocking and
541 * not-to-be-closed-on-exec at this end.
545 if (dup2(in->fd, STDIN_FILENO) < 0 ||
546 dup2(out->fd, STDOUT_FILENO) < 0 ||
547 dup2(fd[1], STDERR_FILENO) < 0) {
548 moan("couldn't manipulate file descriptors: %s", strerror(errno));
557 fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
558 fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
559 fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
561 /* --- First of all set the @chroot@ prison --- */
563 if (xo->root && chroot(xo->root)) {
564 moan("couldn't set `%s' as filesystem root: %s",
565 xo->root, strerror(errno));
569 /* --- Now set the current directory --- */
571 if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) {
572 moan("couldn't set `%s' as current directory: %s",
573 xo->dir ? xo->dir : "/", strerror(errno));
577 /* --- Set the resource limits --- */
579 #ifdef HAVE_SETRLIMIT
583 /* --- Set group id --- */
586 if (setgid(xo->gid)) {
587 moan("couldn't set gid %i: %s", xo->gid, strerror(errno));
590 #ifdef HAVE_SETGROUPS
591 if (setgroups(1, &xo->gid))
592 moan("warning: couldn't set group list to %i: %s", xo->gid,
597 /* --- Set uid --- */
600 if (setuid(xo->uid)) {
601 moan("couldn't set uid %i: %s", xo->uid, strerror(errno));
606 /* --- Play with signal dispositions --- */
608 signal(SIGPIPE, SIG_DFL);
610 /* --- Fiddle with the environment --- */
612 xenv_apply(exec_opts.env);
613 xenv_apply(xe->xo->env);
614 environ = env_export(&env);
616 /* --- Run the program --- */
618 execvp(xe->xa->file, xe->xa->argv);
619 moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno));
623 /* --- The child's done; see to the parent --- */
626 selbuf_init(&xe->err, sel, fd[0], xept_error, xe);
628 xe->next = xept_list;
631 xept_list->prev = xe;
633 if (!(xe->xo->f & XF_NOLOG))
634 fw_log(-1, "[%s] started with pid %i", xe->desc, kid);
639 /* --- @xept_file@ --- */
641 static void xept_file(endpt *e, endpt *f)
643 xept *xe = (xept *)e;
647 /* --- @xept_close@ --- */
649 static void xept_close(endpt *e)
651 xept *xe = (xept *)e;
654 xe->f->ops->close(xe->f);
655 x_tidy(xe->xa, xe->xo);
661 /* --- @xept_destroy@ --- */
663 static void xept_destroy(xept *xe)
665 /* --- First emit the news about the process --- */
667 if (xe->xo->f & XF_NOLOG)
669 else if (WIFEXITED(xe->st)) {
670 if (WEXITSTATUS(xe->st) == 0)
671 fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid);
673 fw_log(-1, "[%s] pid %i failed: status %i",
674 xe->desc, xe->kid, WEXITSTATUS(xe->st));
676 } else if (WIFSIGNALED(xe->st)) {
678 #ifdef HAVE_STRSIGNAL
679 s = strsignal(WTERMSIG(xe->st));
680 #elif HAVE__SYS_SIGLIST
681 s = _sys_siglist[WTERMSIG(xe->st)];
684 sprintf(buf, "signal %i", WTERMSIG(xe->st));
687 fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s);
689 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid);
691 /* --- Free up the parent-side resources --- */
694 xe->next->prev = xe->prev;
696 xe->prev->next = xe->next;
698 xept_list = xe->next;
701 xe->f->ops->close(xe->f);
702 x_tidy(xe->xa, xe->xo);
707 /* --- @xept_chld@ --- *
709 * Arguments: @int n@ = signal number
710 * @void *p@ = uninteresting pointer
714 * Use: Deals with child death situations.
717 static void xept_chld(int n, void *p)
722 while ((kid = waitpid(-1, &st, WNOHANG)) > 0) {
723 xept *xe = xept_list;
727 if (kid == xxe->kid) {
729 xxe->e.f |= XEF_EXIT;
730 if (xxe->e.f & XEF_CLOSE)
738 /* --- @xept_error@ --- *
740 * Arguments: @char *p@ = pointer to string read from stderr
741 * @void *v@ = pointer to by endpoint
745 * Use: Handles error reports from a child process.
748 static void xept_error(char *p, void *v)
752 fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p);
754 close(xe->err.reader.fd);
755 selbuf_destroy(&xe->err);
756 xe->e.f |= XEF_CLOSE;
757 if (xe->e.f & XEF_EXIT)
762 /* --- Endpoint operations --- */
764 static endpt_ops xept_ops = { xept_attach, xept_file, 0, xept_close };
766 /*----- General operations on sources and targets -------------------------*/
768 /* --- @exec_init@ --- *
774 * Use: Initializes the executable problem source and target.
779 rlimit_get(&exec_opts.xl);
780 sig_add(&xept_sig, SIGCHLD, xept_chld, 0);
782 env_import(&env, environ);
785 /* --- @exec_option@ --- */
787 static int exec_option(xdata *x, scanner *sc)
789 xopts *xo = x ? x->xo : &exec_opts;
791 CONF_BEGIN(sc, "exec", "executable");
793 /* --- Logging settings --- */
795 if (strcmp(sc->d.buf, "logging") == 0 ||
796 strcmp(sc->d.buf, "log") == 0) {
800 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
807 /* --- Current directory setting --- *
809 * Lots of possibilities to guard against possible brainoes.
812 if (strcmp(sc->d.buf, "dir") == 0 ||
813 strcmp(sc->d.buf, "cd") == 0 ||
814 strcmp(sc->d.buf, "chdir") == 0 ||
815 strcmp(sc->d.buf, "cwd") == 0) {
820 conf_name(sc, '/', &d);
821 xo->dir = xstrdup(d.buf);
826 /* --- Set a chroot prison --- */
828 if (strcmp(sc->d.buf, "root") == 0 ||
829 strcmp(sc->d.buf, "chroot") == 0) {
834 conf_name(sc, '/', &d);
835 xo->root = xstrdup(d.buf);
840 /* --- Set the target user id --- */
842 if (strcmp(sc->d.buf, "uid") == 0 ||
843 strcmp(sc->d.buf, "user") == 0) {
847 if (sc->t != CTOK_WORD)
848 error(sc, "parse error, expected user name or uid");
849 if (isdigit((unsigned char)*sc->d.buf))
850 xo->uid = atoi(sc->d.buf);
852 struct passwd *pw = getpwnam(sc->d.buf);
854 error(sc, "unknown user name `%s'", sc->d.buf);
855 xo->uid = pw->pw_uid;
861 /* --- Set the target group id --- */
863 if (strcmp(sc->d.buf, "gid") == 0 ||
864 strcmp(sc->d.buf, "group") == 0) {
868 if (sc->t != CTOK_WORD)
869 error(sc, "parse error, expected group name or gid");
870 if (isdigit((unsigned char)*sc->d.buf))
871 xo->gid = atoi(sc->d.buf);
873 struct group *gr = getgrnam(sc->d.buf);
875 error(sc, "unknown user name `%s'", sc->d.buf);
876 xo->gid = gr->gr_gid;
882 /* --- Now try resource limit settings --- */
884 if (rlimit_option(&xo->xl, sc))
887 /* --- And then environment settings --- */
889 if (xenv_option(xo, sc))
892 /* --- Nothing found --- */
897 /* --- @exec_desc@ --- */
899 static void exec_desc(xdata *x, dstr *d)
903 dstr_puts(d, "exec ");
904 if (strcmp(x->xa->file, x->xa->argv[0]) != 0) {
905 dstr_puts(d, x->xa->file);
908 for (p = x->xa->argv; *p; p++) {
917 /* --- @exec_read@ --- */
919 static void exec_read(xdata *x, scanner *sc)
925 /* --- Read the first word --- *
927 * This is either a shell command or the actual program to run.
930 if (sc->t == CTOK_WORD) {
931 dstr_putd(&d, &sc->d); d.len++;
936 /* --- See if there's a list of arguments --- *
938 * If not, then the thing I saw was a shell command, so build the proper
939 * arguments for that.
945 error(sc, "parse error, expected shell command or argument list");
946 xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len);
947 p = (char *)(xa->argv + 4);
950 xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8;
951 xa->argv[1] = p; memcpy(p, "-c", 3); p += 3;
952 xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len;
956 /* --- Snarf in a list of arguments --- */
963 /* --- Strip off the leading `[' --- */
967 /* --- Read a sequence of arguments --- */
969 while (sc->t == CTOK_WORD) {
970 dstr_putd(&d, &sc->d); d.len++;
975 /* --- Expect the closing `]' --- */
978 error(sc, "parse error, missing `]'");
981 /* --- If there are no arguments, whinge --- */
984 error(sc, "must specify at least one argument");
986 /* --- Allocate a lump of memory for the array --- */
988 xa = xmalloc(XARGS_SZ(argc) + d.len);
991 p = (char *)(v + argc + 1);
992 memcpy(p, d.buf, d.len);
997 /* --- Start dumping addresses into the @argv@ array --- */
1001 while (*p++ && p < q)
1009 /* --- Do some other setting up --- */
1013 x->xo = CREATE(xopts);
1019 /* --- @exec_endpt@ --- */
1021 static endpt *exec_endpt(xdata *x, const char *desc)
1023 xept *xe = CREATE(xept);
1024 xe->e.ops = &xept_ops;
1028 xe->xa = x->xa; xe->xa->ref++;
1029 xe->xo = x->xo; xe->xo->ref++;
1036 /* --- @exec_destroy@ --- */
1038 static void exec_destroy(xdata *x)
1040 x_tidy(x->xa, x->xo);
1043 /*----- Source definition -------------------------------------------------*/
1045 /* --- @option@ --- */
1047 static int xsource_option(source *s, scanner *sc)
1049 xsource *xs = (xsource *)s;
1050 return (exec_option(xs ? &xs->x : 0, sc));
1053 /* --- @read@ --- */
1055 static source *xsource_read(scanner *sc)
1059 if (!conf_prefix(sc, "exec"))
1061 xs = CREATE(xsource);
1062 xs->s.ops = &xsource_ops;
1064 exec_read(&xs->x, sc);
1068 /* --- @attach@ --- */
1070 static void xsource_destroy(source */*s*/);
1072 static void xsource_attach(source *s, scanner *sc, target *t)
1074 xsource *xs = (xsource *)s;
1077 /* --- Set up the source description string --- */
1081 exec_desc(&xs->x, &d);
1082 dstr_puts(&d, " -> ");
1083 dstr_puts(&d, t->desc);
1084 xs->s.desc = xstrdup(d.buf);
1088 /* --- Create the endpoints --- */
1090 if ((ee = t->ops->create(t, xs->s.desc)) == 0)
1092 if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) {
1098 /* --- Dispose of source and target --- */
1102 xsource_destroy(&xs->s);
1105 /* --- @destroy@ --- */
1107 static void xsource_destroy(source *s)
1109 xsource *xs = (xsource *)s;
1110 exec_destroy(&xs->x);
1114 /* --- Executable source operations --- */
1116 source_ops xsource_ops = {
1118 xsource_option, xsource_read, xsource_attach, xsource_destroy
1121 /*----- Exec target description -------------------------------------------*/
1123 /* --- @option@ --- */
1125 static int xtarget_option(target *t, scanner *sc)
1127 xtarget *xt = (xtarget *)t;
1128 return (exec_option(xt ? &xt->x : 0, sc));
1131 /* --- @read@ --- */
1133 static target *xtarget_read(scanner *sc)
1138 if (!conf_prefix(sc, "exec"))
1140 xt = CREATE(xtarget);
1141 xt->t.ops = &xtarget_ops;
1142 exec_read(&xt->x, sc);
1143 exec_desc(&xt->x, &d);
1144 xt->t.desc = xstrdup(d.buf);
1149 /* --- @create@ --- */
1151 static endpt *xtarget_create(target *t, const char *desc)
1153 xtarget *xt = (xtarget *)t;
1154 endpt *e = exec_endpt(&xt->x, desc);
1158 /* --- @destroy@ --- */
1160 static void xtarget_destroy(target *t)
1162 xtarget *xt = (xtarget *)t;
1163 exec_destroy(&xt->x);
1167 /* --- Exec target operations --- */
1169 target_ops xtarget_ops = {
1171 xtarget_option, xtarget_read, xtarget_create, xtarget_destroy
1174 /*----- That's all, folks -------------------------------------------------*/