3 * $Id: exec.c,v 1.1 1999/07/26 23:33:32 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 1.1 1999/07/26 23:33:32 mdw
33 * New sources and targets.
37 /*----- Header files ------------------------------------------------------*/
50 #include <sys/types.h>
57 # include <sys/resource.h>
61 extern char **environ;
69 #include <mLib/alloc.h>
70 #include <mLib/dstr.h>
72 #include <mLib/fdflags.h>
73 #include <mLib/report.h>
75 #include <mLib/selbuf.h>
90 /*----- Data structures ---------------------------------------------------*/
92 /* --- Resource usage --- */
96 typedef struct xlimit {
97 #define R(r, n) struct rlimit n;
103 /* --- Environment variable modifications --- */
105 typedef struct xenv {
115 /* --- Program options --- */
117 typedef struct xopts {
126 #ifdef HAVE_SETRLIMIT
133 /* --- Executable program arguments --- */
135 typedef struct xargs {
141 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
143 /* --- Executable endpoints --- */
145 typedef struct xept {
147 struct xept *next, *prev;
156 #define XEF_CLOSE 16u
159 /* --- Executable program data --- */
161 typedef struct xdata {
166 /* --- Executable source block --- */
168 typedef struct xsource {
173 /* --- Executable target block --- */
175 typedef struct xtarget {
180 /*----- Static variables --------------------------------------------------*/
182 static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env };
183 static xept *xept_list;
185 static sym_table env;
187 /*----- Fiddling about with resource limits -------------------------------*/
189 #ifdef HAVE_SETRLIMIT
191 /* --- Table mapping user-level names to OS interface bits --- */
193 typedef struct rlimit_ent {
200 static rlimit_ent rlimits[] = {
201 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
206 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
208 /* --- @rlimit_get@ --- *
210 * Arguments: @xlimit *xl@ = pointer to limit structure
214 * Use: Initializes a limit structure from the current limits.
217 static void rlimit_get(xlimit *xl)
221 for (r = rlimits; r->name; r++) {
222 if (getrlimit(r->r, RLIMIT(xl, r->off))) {
223 moan("couldn't read %s: %s", r->rname, strerror(errno));
229 /* --- @rlimit_set@ --- *
231 * Arguments: @xlimit *xl@ = pointer to limit structure
235 * Use: Sets resource limits from the supplied limits structure.
238 static void rlimit_set(xlimit *xl)
242 for (r = rlimits; r->name; r++) {
243 if (setrlimit(r->r, RLIMIT(xl, r->off))) {
244 moan("couldn't set %s: %s", r->rname, strerror(errno));
250 /* --- @rlimit_option@ --- */
252 static int rlimit_option(xlimit *xl, scanner *sc)
254 CONF_BEGIN(sc, "rlimit", "resource limit")
255 enum { w_soft, w_hard, w_both } which = w_both;
260 /* --- Find out which resource is being fiddled --- */
266 for (r = rlimits; r->name; r++) {
267 if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) {
268 if (r->name[sc->d.len] == 0) {
272 error(sc, "ambiguous resource limit name `%s'", sc->d.buf);
280 rl = RLIMIT(xl, chosen->off);
283 /* --- Look for hard or soft restrictions --- */
289 if (sc->t == CTOK_WORD) {
290 if ((i = conf_enum(sc, "soft,hard",
291 ENUM_ABBREV | ENUM_NONE, "limit type")) != -1)
296 /* --- Now read the new value --- */
300 if (sc->t != CTOK_WORD)
301 error(sc, "parse error, expected limit value");
303 if (conf_enum(sc, "unlimited,infinity",
304 ENUM_ABBREV | ENUM_NONE, "limit value") > -1)
309 v = strtol(sc->d.buf, &p, 0);
311 error(sc, "parse error, invalid limit value `%s'", sc->d.buf);
312 switch (tolower((unsigned char)*p)) {
314 case 'b': v *= 512; break;
317 case 'k': v *= 1024; break;
318 default: error(sc, "parse error, invalid limit scale `%c'", *p);
323 /* --- Store the limit value away --- */
331 if (v > rl->rlim_max)
332 error(sc, "soft limit %l exceeds hard limit %l for %s",
333 v, rl->rlim_max, chosen->rname);
338 if (rl->rlim_cur > v)
349 /*----- Environment fiddling ----------------------------------------------*/
351 /* --- @xenv_option@ --- *
353 * Arguments: @xopts *xo@ = pointer to options block
354 * @scanner *sc@ = pointer to scanner
356 * Returns: Nonzero if claimed
358 * Use: Parses environment variable assignments.
361 static int xenv_option(xopts *xo, scanner *sc)
363 CONF_BEGIN(sc, "env", "environment")
366 /* --- Unset a variable --- */
368 if (strcmp(sc->d.buf, "unset") == 0) {
370 if (sc->t != CTOK_WORD)
371 error(sc, "parse error, expected environment variable name");
373 xe->name = xstrdup(sc->d.buf);
380 /* --- Clear the entire environment --- */
382 if (strcmp(sc->d.buf, "clear") == 0) {
389 /* --- Allow `set' to be omitted if there's a prefix --- */
391 if (strcmp(sc->d.buf, "set") == 0)
396 /* --- Set a variable --- */
398 if (sc->t != CTOK_WORD)
399 error(sc, "parse error, expected environment variable name");
401 xe->name = xstrdup(sc->d.buf);
405 if (sc->t != CTOK_WORD)
406 error(sc, "parse error, expected environment variable value");
407 xe->value = xstrdup(sc->d.buf);
415 xo->etail = &xe->next;
418 /* --- Nothing else to try --- */
423 /* --- @xenv_apply@ --- *
425 * Arguments: @xenv *xe@ = pointer to a variable change list
429 * Use: Modifies the environment (in @env@) according to the list.
432 static void xenv_apply(xenv *xe)
437 env_put(&env, xe->name, xe->value);
448 /* --- @xenv_destroy@ --- *
450 * Arguments: @xenv *xe@ = pointer to a variable change list
454 * Use: Frees the memory used by an environment variable change list.
457 static void xenv_destroy(xenv *xe)
469 /*----- Miscellaneous good things -----------------------------------------*/
471 /* --- @x_tidy@ --- *
473 * Arguments: @xargs *xa@ = pointer to an arguments block
474 * @xopts *xo@ = pointer to an options block
478 * Use: Releases a reference to argument and options blocks.
481 static void x_tidy(xargs *xa, xopts *xo)
489 xenv_destroy(xo->env);
494 /*----- Executable endpoints ----------------------------------------------*/
496 /* --- @attach@ --- */
498 static void xept_error(char */*p*/, void */*v*/);
500 static void xept_attach(endpt *e, reffd *in, reffd *out)
502 xept *xe = (xept *)e;
506 /* --- Make a pipe for standard error --- */
509 fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno));
512 fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
514 /* --- Fork a child, and handle an error if there was one --- */
516 if ((kid = fork()) == -1) {
517 fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno));
523 /* --- Do the child thing --- */
528 /* --- Fiddle with the file descriptors --- *
530 * Attach the other endpoint's descriptors to standard input and output.
531 * Attach my pipe to standard error. Mark everything as blocking and
532 * not-to-be-closed-on-exec at this end.
536 if (dup2(in->fd, STDIN_FILENO) < 0 ||
537 dup2(out->fd, STDOUT_FILENO) < 0 ||
538 dup2(fd[1], STDERR_FILENO) < 0) {
539 moan("couldn't manipulate file descriptors: %s", strerror(errno));
548 fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
549 fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
550 fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
552 /* --- First of all set the @chroot@ prison --- */
554 if (xo->root && chroot(xo->root)) {
555 moan("couldn't set `%s' as filesystem root: %s",
556 xo->root, strerror(errno));
560 /* --- Now set the current directory --- */
562 if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) {
563 moan("couldn't set `%s' as current directory: %s",
564 xo->dir ? xo->dir : "/", strerror(errno));
568 /* --- Set the resource limits --- */
570 #ifdef HAVE_SETRLIMIT
574 /* --- Set group id --- */
577 if (setgid(xo->gid)) {
578 moan("couldn't set gid %i: %s", xo->gid, strerror(errno));
581 #ifdef HAVE_SETGROUPS
582 if (setgroups(1, &xo->gid))
583 moan("warning: couldn't set group list to %i: %s", xo->gid,
588 /* --- Set uid --- */
591 if (setuid(xo->uid)) {
592 moan("couldn't set uid %i: %s", xo->uid, strerror(errno));
597 /* --- Play with signal dispositions --- */
599 signal(SIGPIPE, SIG_DFL);
601 /* --- Fiddle with the environment --- */
603 xenv_apply(exec_opts.env);
604 xenv_apply(xe->xo->env);
605 environ = env_export(&env);
607 /* --- Run the program --- */
609 execvp(xe->xa->file, xe->xa->argv);
610 moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno));
614 /* --- The child's done; see to the parent --- */
617 selbuf_init(&xe->err, sel, fd[0], xept_error, xe);
619 xe->next = xept_list;
622 xept_list->prev = xe;
624 if (!(xe->xo->f & XF_NOLOG))
625 fw_log(-1, "[%s] started with pid %i", xe->desc, kid);
630 /* --- @xept_close@ --- */
632 static void xept_close(endpt *e)
634 xept *xe = (xept *)e;
636 x_tidy(xe->xa, xe->xo);
642 /* --- @xept_destroy@ --- */
644 static void xept_destroy(xept *xe)
646 /* --- First emit the news about the process --- */
648 if (xe->xo->f & XF_NOLOG)
650 else if (WIFEXITED(xe->st)) {
651 if (WEXITSTATUS(xe->st) == 0)
652 fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid);
654 fw_log(-1, "[%s] pid %i failed: status %i",
655 xe->desc, xe->kid, WEXITSTATUS(xe->st));
657 } else if (WIFSIGNALED(xe->st)) {
659 #ifdef HAVE_STRSIGNAL
660 s = strsignal(WTERMSIG(xe->st));
661 #elif HAVE__SYS_SIGLIST
662 s = _sys_siglist[WTERMSIG(xe->st)];
665 sprintf(buf, "signal %i", WTERMSIG(xe->st));
668 fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s);
670 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid);
672 /* --- Free up the parent-side resources --- */
675 xe->next->prev = xe->prev;
677 xe->prev->next = xe->next;
679 xept_list = xe->next;
681 x_tidy(xe->xa, xe->xo);
686 /* --- @xept_chld@ --- *
688 * Arguments: @int n@ = signal number
689 * @void *p@ = uninteresting pointer
693 * Use: Deals with child death situations.
696 static void xept_chld(int n, void *p)
701 while ((kid = waitpid(-1, &st, WNOHANG)) > 0) {
702 xept *xe = xept_list;
706 if (kid == xxe->kid) {
708 xxe->e.f |= XEF_EXIT;
709 if (xxe->e.f & XEF_CLOSE)
717 /* --- @xept_error@ --- *
719 * Arguments: @char *p@ = pointer to string read from stderr
720 * @void *v@ = pointer to by endpoint
724 * Use: Handles error reports from a child process.
727 static void xept_error(char *p, void *v)
731 fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p);
733 selbuf_disable(&xe->err);
734 close(xe->err.reader.fd);
735 xe->e.f |= XEF_CLOSE;
736 if (xe->e.f & XEF_EXIT)
741 /* --- Endpoint operations --- */
743 static endpt_ops xept_ops = { xept_attach, 0, xept_close };
745 /*----- General operations on sources and targets -------------------------*/
747 /* --- @exec_init@ --- *
753 * Use: Initializes the executable problem source and target.
758 rlimit_get(&exec_opts.xl);
759 sig_add(&xept_sig, SIGCHLD, xept_chld, 0);
761 env_import(&env, environ);
764 /* --- @exec_option@ --- */
766 static int exec_option(xdata *x, scanner *sc)
768 xopts *xo = x ? x->xo : &exec_opts;
770 CONF_BEGIN(sc, "exec", "executable");
772 /* --- Logging settings --- */
774 if (strcmp(sc->d.buf, "logging") == 0 ||
775 strcmp(sc->d.buf, "log") == 0) {
779 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
786 /* --- Current directory setting --- *
788 * Lots of possibilities to guard against possible brainoes.
791 if (strcmp(sc->d.buf, "dir") == 0 ||
792 strcmp(sc->d.buf, "cd") == 0 ||
793 strcmp(sc->d.buf, "chdir") == 0 ||
794 strcmp(sc->d.buf, "cwd") == 0) {
799 conf_name(sc, '/', &d);
800 xo->dir = xstrdup(d.buf);
805 /* --- Set a chroot prison --- */
807 if (strcmp(sc->d.buf, "root") == 0 ||
808 strcmp(sc->d.buf, "chroot") == 0) {
813 conf_name(sc, '/', &d);
814 xo->root = xstrdup(d.buf);
819 /* --- Set the target user id --- */
821 if (strcmp(sc->d.buf, "uid") == 0 ||
822 strcmp(sc->d.buf, "user") == 0) {
826 if (sc->t != CTOK_WORD)
827 error(sc, "parse error, expected user name or uid");
828 if (isdigit((unsigned char)*sc->d.buf))
829 xo->uid = atoi(sc->d.buf);
831 struct passwd *pw = getpwnam(sc->d.buf);
833 error(sc, "unknown user name `%s'", sc->d.buf);
834 xo->uid = pw->pw_uid;
840 /* --- Set the target group id --- */
842 if (strcmp(sc->d.buf, "gid") == 0 ||
843 strcmp(sc->d.buf, "group") == 0) {
847 if (sc->t != CTOK_WORD)
848 error(sc, "parse error, expected group name or gid");
849 if (isdigit((unsigned char)*sc->d.buf))
850 xo->gid = atoi(sc->d.buf);
852 struct group *gr = getgrnam(sc->d.buf);
854 error(sc, "unknown user name `%s'", sc->d.buf);
855 xo->gid = gr->gr_gid;
861 /* --- Now try resource limit settings --- */
863 if (rlimit_option(&xo->xl, sc))
866 /* --- And then environment settings --- */
868 if (xenv_option(xo, sc))
871 /* --- Nothing found --- */
876 /* --- @exec_desc@ --- */
878 static void exec_desc(xdata *x, dstr *d)
882 dstr_puts(d, "exec ");
883 if (strcmp(x->xa->file, x->xa->argv[0]) != 0) {
884 dstr_puts(d, x->xa->file);
887 for (p = x->xa->argv; *p; p++) {
896 /* --- @exec_read@ --- */
898 static void exec_read(xdata *x, scanner *sc)
904 /* --- Read the first word --- *
906 * This is either a shell command or the actual program to run.
909 if (sc->t == CTOK_WORD) {
910 dstr_putd(&d, &sc->d); d.len++;
915 /* --- See if there's a list of arguments --- *
917 * If not, then the thing I saw was a shell command, so build the proper
918 * arguments for that.
924 error(sc, "parse error, expected shell command or argument list");
925 xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len);
926 p = (char *)(xa->argv + 4);
929 xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8;
930 xa->argv[1] = p; memcpy(p, "-c", 3); p += 3;
931 xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len;
935 /* --- Snarf in a list of arguments --- */
942 /* --- Strip off the leading `[' --- */
946 /* --- Read a sequence of arguments --- */
948 while (sc->t == CTOK_WORD) {
949 dstr_putd(&d, &sc->d); d.len++;
954 /* --- Expect the closing `]' --- */
957 error(sc, "parse error, missing `]'");
960 /* --- If there are no arguments, whinge --- */
963 error(sc, "must specify at least one argument");
965 /* --- Allocate a lump of memory for the array --- */
967 xa = xmalloc(XARGS_SZ(argc) + d.len);
970 p = (char *)(v + argc + 1);
971 memcpy(p, d.buf, d.len);
976 /* --- Start dumping addresses into the @argv@ array --- */
980 while (*p++ && p < q)
988 /* --- Do some other setting up --- */
992 x->xo = CREATE(xopts);
998 /* --- @exec_endpt@ --- */
1000 static endpt *exec_endpt(xdata *x, const char *desc)
1002 xept *xe = CREATE(xept);
1003 xe->e.ops = &xept_ops;
1007 xe->xa = x->xa; xe->xa->ref++;
1008 xe->xo = x->xo; xe->xo->ref++;
1014 /* --- @exec_destroy@ --- */
1016 static void exec_destroy(xdata *x)
1018 x_tidy(x->xa, x->xo);
1021 /*----- Source definition -------------------------------------------------*/
1023 /* --- @option@ --- */
1025 static int xsource_option(source *s, scanner *sc)
1027 xsource *xs = (xsource *)s;
1028 return (exec_option(xs ? &xs->x : 0, sc));
1031 /* --- @read@ --- */
1033 static source *xsource_read(scanner *sc)
1037 if (!conf_prefix(sc, "exec"))
1039 xs = CREATE(xsource);
1040 xs->s.ops = &xsource_ops;
1042 exec_read(&xs->x, sc);
1046 /* --- @attach@ --- */
1048 static void xsource_destroy(source */*s*/);
1050 static void xsource_attach(source *s, scanner *sc, target *t)
1052 xsource *xs = (xsource *)s;
1055 /* --- Set up the source description string --- */
1059 exec_desc(&xs->x, &d);
1060 dstr_puts(&d, " -> ");
1061 dstr_puts(&d, t->desc);
1062 xs->s.desc = xstrdup(d.buf);
1066 /* --- Create the endpoints --- */
1068 if ((ee = t->ops->create(t, xs->s.desc)) == 0)
1070 if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) {
1076 /* --- Dispose of source and target --- */
1080 xsource_destroy(&xs->s);
1083 /* --- @destroy@ --- */
1085 static void xsource_destroy(source *s)
1087 xsource *xs = (xsource *)s;
1088 exec_destroy(&xs->x);
1092 /* --- Executable source operations --- */
1094 source_ops xsource_ops = {
1096 xsource_option, xsource_read, xsource_attach, xsource_destroy
1099 /*----- Exec target description -------------------------------------------*/
1101 /* --- @option@ --- */
1103 static int xtarget_option(target *t, scanner *sc)
1105 xtarget *xt = (xtarget *)t;
1106 return (exec_option(xt ? &xt->x : 0, sc));
1109 /* --- @read@ --- */
1111 static target *xtarget_read(scanner *sc)
1116 if (!conf_prefix(sc, "exec"))
1118 xt = CREATE(xtarget);
1119 xt->t.ops = &xtarget_ops;
1120 exec_read(&xt->x, sc);
1121 exec_desc(&xt->x, &d);
1122 xt->t.desc = xstrdup(d.buf);
1127 /* --- @create@ --- */
1129 static endpt *xtarget_create(target *t, const char *desc)
1131 xtarget *xt = (xtarget *)t;
1132 endpt *e = exec_endpt(&xt->x, desc);
1136 /* --- @destroy@ --- */
1138 static void xtarget_destroy(target *t)
1140 xtarget *xt = (xtarget *)t;
1141 exec_destroy(&xt->x);
1145 /* --- Exec target operations --- */
1147 target_ops xtarget_ops = {
1149 xtarget_option, xtarget_read, xtarget_create, xtarget_destroy
1152 /*----- That's all, folks -------------------------------------------------*/