3 * Source and target for executable programs
5 * (c) 1999 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the `fw' port forwarder.
12 * `fw' is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * `fw' is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with `fw'; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 /*----- Header files ------------------------------------------------------*/
40 #include <sys/types.h>
47 # include <sys/resource.h>
51 extern char **environ;
59 #include <mLib/alloc.h>
60 #include <mLib/dstr.h>
62 #include <mLib/fdflags.h>
63 #include <mLib/report.h>
65 #include <mLib/selbuf.h>
80 /*----- Data structures ---------------------------------------------------*/
82 /* --- Resource usage --- */
86 typedef struct xlimit {
87 #define R(r, n) struct rlimit n;
93 /* --- Environment variable modifications --- */
105 /* --- Program options --- */
107 typedef struct xopts {
116 #ifdef HAVE_SETRLIMIT
123 /* --- Executable program arguments --- */
125 typedef struct xargs {
131 #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n))
133 /* --- Executable endpoints --- */
135 typedef struct xept {
137 struct xept *next, *prev;
147 #define XEF_CLOSE 16u
150 /* --- Executable program data --- */
152 typedef struct xdata {
157 /* --- Executable source block --- */
159 typedef struct xsource {
164 /* --- Executable target block --- */
166 typedef struct xtarget {
171 /*----- Static variables --------------------------------------------------*/
173 static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env };
174 static xept *xept_list;
176 static sym_table env;
178 /*----- Fiddling about with resource limits -------------------------------*/
180 #ifdef HAVE_SETRLIMIT
182 /* --- Table mapping user-level names to OS interface bits --- */
184 typedef struct rlimit_ent {
191 static rlimit_ent rlimits[] = {
192 #define R(r, n) { #n, #r, r, offsetof(xlimit, n) },
197 #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o)))
199 /* --- @rlimit_get@ --- *
201 * Arguments: @xlimit *xl@ = pointer to limit structure
205 * Use: Initializes a limit structure from the current limits.
208 static void rlimit_get(xlimit *xl)
212 for (r = rlimits; r->name; r++) {
213 if (getrlimit(r->r, RLIMIT(xl, r->off))) {
214 moan("couldn't read %s: %s", r->rname, strerror(errno));
220 /* --- @rlimit_set@ --- *
222 * Arguments: @xlimit *xl@ = pointer to limit structure
226 * Use: Sets resource limits from the supplied limits structure.
229 static void rlimit_set(xlimit *xl)
233 for (r = rlimits; r->name; r++) {
234 if (setrlimit(r->r, RLIMIT(xl, r->off))) {
235 moan("couldn't set %s: %s", r->rname, strerror(errno));
241 /* --- @rlimit_option@ --- */
243 static int rlimit_option(xlimit *xl, scanner *sc)
245 CONF_BEGIN(sc, "rlimit", "resource limit")
246 enum { w_soft, w_hard, w_both } which = w_both;
251 /* --- Find out which resource is being fiddled --- */
257 for (r = rlimits; r->name; r++) {
258 if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) {
259 if (r->name[sc->d.len] == 0) {
263 error(sc, "ambiguous resource limit name `%s'", sc->d.buf);
271 rl = RLIMIT(xl, chosen->off);
274 /* --- Look for hard or soft restrictions --- */
280 if (sc->t == CTOK_WORD) {
281 if ((i = conf_enum(sc, "soft,hard",
282 ENUM_ABBREV | ENUM_NONE, "limit type")) != -1)
287 /* --- Now read the new value --- */
291 if (sc->t != CTOK_WORD)
292 error(sc, "parse error, expected limit value");
294 if (conf_enum(sc, "unlimited,infinity",
295 ENUM_ABBREV | ENUM_NONE, "limit value") > -1)
300 v = strtol(sc->d.buf, &p, 0);
302 error(sc, "parse error, invalid limit value `%s'", sc->d.buf);
303 switch (tolower((unsigned char)*p)) {
305 case 'b': v *= 512; break;
308 case 'k': v *= 1024; break;
309 default: error(sc, "parse error, invalid limit scale `%c'", *p);
314 /* --- Store the limit value away --- */
322 if (v > rl->rlim_max)
323 error(sc, "soft limit %l exceeds hard limit %l for %s",
324 v, rl->rlim_max, chosen->rname);
329 if (rl->rlim_cur > v)
340 /*----- Environment fiddling ----------------------------------------------*/
342 /* --- @xenv_option@ --- *
344 * Arguments: @xopts *xo@ = pointer to options block
345 * @scanner *sc@ = pointer to scanner
347 * Returns: Nonzero if claimed
349 * Use: Parses environment variable assignments.
352 static int xenv_option(xopts *xo, scanner *sc)
354 CONF_BEGIN(sc, "env", "environment")
357 /* --- Unset a variable --- */
359 if (strcmp(sc->d.buf, "unset") == 0) {
361 if (sc->t != CTOK_WORD)
362 error(sc, "parse error, expected environment variable name");
364 xe->name = xstrdup(sc->d.buf);
371 /* --- Clear the entire environment --- */
373 if (strcmp(sc->d.buf, "clear") == 0) {
380 /* --- Allow `set' to be omitted if there's a prefix --- */
382 if (strcmp(sc->d.buf, "set") == 0)
387 /* --- Set a variable --- */
389 if (sc->t != CTOK_WORD)
390 error(sc, "parse error, expected environment variable name");
392 xe->name = xstrdup(sc->d.buf);
396 if (sc->t != CTOK_WORD)
397 error(sc, "parse error, expected environment variable value");
398 xe->value = xstrdup(sc->d.buf);
406 xo->etail = &xe->next;
409 /* --- Nothing else to try --- */
414 /* --- @xenv_apply@ --- *
416 * Arguments: @xenv *xe@ = pointer to a variable change list
420 * Use: Modifies the environment (in @env@) according to the list.
423 static void xenv_apply(xenv *xe)
428 env_put(&env, xe->name, xe->value);
439 /* --- @xenv_destroy@ --- *
441 * Arguments: @xenv *xe@ = pointer to a variable change list
445 * Use: Frees the memory used by an environment variable change list.
448 static void xenv_destroy(xenv *xe)
460 /*----- Miscellaneous good things -----------------------------------------*/
462 /* --- @x_tidy@ --- *
464 * Arguments: @xargs *xa@ = pointer to an arguments block
465 * @xopts *xo@ = pointer to an options block
469 * Use: Releases a reference to argument and options blocks.
472 static void x_tidy(xargs *xa, xopts *xo)
480 xenv_destroy(xo->env);
485 /*----- Executable endpoints ----------------------------------------------*/
487 /* --- @attach@ --- */
489 static void xept_error(char */*p*/, size_t /*len*/, void */*v*/);
491 static void xept_attach(endpt *e, reffd *in, reffd *out)
493 xept *xe = (xept *)e;
497 /* --- Make a pipe for standard error --- */
500 fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno));
503 fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
505 /* --- Fork a child, and handle an error if there was one --- */
507 if ((kid = fork()) == -1) {
508 fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno));
514 /* --- Do the child thing --- */
519 /* --- Fiddle with the file descriptors --- *
521 * Attach the other endpoint's descriptors to standard input and output.
522 * Attach my pipe to standard error. Mark everything as blocking and
523 * not-to-be-closed-on-exec at this end.
527 if (dup2(in->fd, STDIN_FILENO) < 0 ||
528 dup2(out->fd, STDOUT_FILENO) < 0 ||
529 dup2(fd[1], STDERR_FILENO) < 0) {
530 moan("couldn't manipulate file descriptors: %s", strerror(errno));
539 fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
540 fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
541 fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
543 /* --- First of all set the @chroot@ prison --- */
545 if (xo->root && chroot(xo->root)) {
546 moan("couldn't set `%s' as filesystem root: %s",
547 xo->root, strerror(errno));
551 /* --- Now set the current directory --- */
553 if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) {
554 moan("couldn't set `%s' as current directory: %s",
555 xo->dir ? xo->dir : "/", strerror(errno));
559 /* --- Set the resource limits --- */
561 #ifdef HAVE_SETRLIMIT
565 /* --- Set group id --- */
567 if (xo->gid != (gid_t)-1) {
568 if (setgid(xo->gid)) {
569 moan("couldn't set gid %i: %s", xo->gid, strerror(errno));
572 #ifdef HAVE_SETGROUPS
573 if (setgroups(1, &xo->gid))
574 moan("warning: couldn't set group list to %i: %s", xo->gid,
579 /* --- Set uid --- */
581 if (xo->uid != (uid_t)-1) {
582 if (setuid(xo->uid)) {
583 moan("couldn't set uid %i: %s", xo->uid, strerror(errno));
588 /* --- Play with signal dispositions --- */
590 signal(SIGPIPE, SIG_DFL);
592 /* --- Fiddle with the environment --- */
594 xenv_apply(exec_opts.env);
595 xenv_apply(xe->xo->env);
596 environ = env_export(&env);
598 /* --- Run the program --- */
600 execvp(xe->xa->file, xe->xa->argv);
601 moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno));
605 /* --- The child's done; see to the parent --- */
608 selbuf_init(&xe->err, sel, fd[0], xept_error, xe);
610 xe->next = xept_list;
613 xept_list->prev = xe;
615 if (!(xe->xo->f & XF_NOLOG))
616 fw_log(-1, "[%s] started with pid %i", xe->desc, kid);
621 /* --- @xept_file@ --- */
623 static void xept_file(endpt *e, endpt *f)
625 xept *xe = (xept *)e;
629 /* --- @xept_close@ --- */
631 static void xept_close(endpt *e)
633 xept *xe = (xept *)e;
636 xe->f->ops->close(xe->f);
637 x_tidy(xe->xa, xe->xo);
643 /* --- @xept_destroy@ --- */
645 static void xept_destroy(xept *xe)
647 /* --- First emit the news about the process --- */
649 if (xe->xo->f & XF_NOLOG)
651 else if (WIFEXITED(xe->st)) {
652 if (WEXITSTATUS(xe->st) == 0)
653 fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid);
655 fw_log(-1, "[%s] pid %i failed: status %i",
656 xe->desc, xe->kid, WEXITSTATUS(xe->st));
658 } else if (WIFSIGNALED(xe->st)) {
660 #ifdef HAVE_STRSIGNAL
661 s = strsignal(WTERMSIG(xe->st));
662 #elif HAVE__SYS_SIGLIST
663 s = _sys_siglist[WTERMSIG(xe->st)];
666 sprintf(buf, "signal %i", WTERMSIG(xe->st));
669 fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s);
671 fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid);
673 /* --- Free up the parent-side resources --- */
676 xe->next->prev = xe->prev;
678 xe->prev->next = xe->next;
680 xept_list = xe->next;
684 xe->f->ops->close(xe->f);
685 x_tidy(xe->xa, xe->xo);
690 /* --- @xept_chld@ --- *
692 * Arguments: @int n@ = signal number
693 * @void *p@ = uninteresting pointer
697 * Use: Deals with child death situations.
700 static void xept_chld(int n, void *p)
705 while ((kid = waitpid(-1, &st, WNOHANG)) > 0) {
706 xept *xe = xept_list;
710 if (kid == xxe->kid) {
712 xxe->e.f |= XEF_EXIT;
713 if (xxe->e.f & XEF_CLOSE)
721 /* --- @xept_error@ --- *
723 * Arguments: @char *p@ = pointer to string read from stderr
724 * @size_t len@ = length of the string
725 * @void *v@ = pointer to by endpoint
729 * Use: Handles error reports from a child process.
732 static void xept_error(char *p, size_t len, void *v)
736 fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p);
738 close(xe->err.reader.fd);
739 selbuf_destroy(&xe->err);
740 xe->e.f |= XEF_CLOSE;
741 if (xe->e.f & XEF_EXIT)
746 /* --- Endpoint operations --- */
748 static endpt_ops xept_ops = { xept_attach, xept_file, 0, xept_close };
750 /*----- General operations on sources and targets -------------------------*/
752 /* --- @exec_init@ --- *
758 * Use: Initializes the executable problem source and target.
763 #ifdef HAVE_SETRLIMIT
764 rlimit_get(&exec_opts.xl);
766 sig_add(&xept_sig, SIGCHLD, xept_chld, 0);
768 env_import(&env, environ);
771 /* --- @exec_option@ --- */
773 static int exec_option(xdata *x, scanner *sc)
775 xopts *xo = x ? x->xo : &exec_opts;
777 CONF_BEGIN(sc, "exec", "executable");
779 /* --- Logging settings --- */
781 if (strcmp(sc->d.buf, "logging") == 0 ||
782 strcmp(sc->d.buf, "log") == 0) {
786 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
793 /* --- Current directory setting --- *
795 * Lots of possibilities to guard against possible brainoes.
798 if (strcmp(sc->d.buf, "dir") == 0 ||
799 strcmp(sc->d.buf, "cd") == 0 ||
800 strcmp(sc->d.buf, "chdir") == 0 ||
801 strcmp(sc->d.buf, "cwd") == 0) {
806 conf_name(sc, '/', &d);
807 xo->dir = xstrdup(d.buf);
812 /* --- Set a chroot prison --- */
814 if (strcmp(sc->d.buf, "root") == 0 ||
815 strcmp(sc->d.buf, "chroot") == 0) {
820 conf_name(sc, '/', &d);
821 xo->root = xstrdup(d.buf);
826 /* --- Set the target user id --- */
828 if (strcmp(sc->d.buf, "uid") == 0 ||
829 strcmp(sc->d.buf, "user") == 0) {
833 if (sc->t != CTOK_WORD)
834 error(sc, "parse error, expected user name or uid");
835 if (isdigit((unsigned char)*sc->d.buf))
836 xo->uid = atoi(sc->d.buf);
838 struct passwd *pw = getpwnam(sc->d.buf);
840 error(sc, "unknown user name `%s'", sc->d.buf);
841 xo->uid = pw->pw_uid;
847 /* --- Set the target group id --- */
849 if (strcmp(sc->d.buf, "gid") == 0 ||
850 strcmp(sc->d.buf, "group") == 0) {
854 if (sc->t != CTOK_WORD)
855 error(sc, "parse error, expected group name or gid");
856 if (isdigit((unsigned char)*sc->d.buf))
857 xo->gid = atoi(sc->d.buf);
859 struct group *gr = getgrnam(sc->d.buf);
861 error(sc, "unknown user name `%s'", sc->d.buf);
862 xo->gid = gr->gr_gid;
868 /* --- Now try resource limit settings --- */
870 #ifdef HAVE_SETRLIMIT
871 if (rlimit_option(&xo->xl, sc))
875 /* --- And then environment settings --- */
877 if (xenv_option(xo, sc))
880 /* --- Nothing found --- */
885 /* --- @exec_desc@ --- */
887 static void exec_desc(xdata *x, dstr *d)
891 dstr_puts(d, "exec ");
892 if (strcmp(x->xa->file, x->xa->argv[0]) != 0) {
893 dstr_puts(d, x->xa->file);
896 for (p = x->xa->argv; *p; p++) {
905 /* --- @exec_read@ --- */
907 static void exec_read(xdata *x, scanner *sc)
913 /* --- Read the first word --- *
915 * This is either a shell command or the actual program to run.
918 if (sc->t == CTOK_WORD) {
919 dstr_putd(&d, &sc->d); d.len++;
924 /* --- See if there's a list of arguments --- *
926 * If not, then the thing I saw was a shell command, so build the proper
927 * arguments for that.
933 error(sc, "parse error, expected shell command or argument list");
934 xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len);
935 p = (char *)(xa->argv + 4);
938 xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8;
939 xa->argv[1] = p; memcpy(p, "-c", 3); p += 3;
940 xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len;
944 /* --- Snarf in a list of arguments --- */
951 /* --- Strip off the leading `[' --- *
953 * Allow various handy filename characters to be entered without quoting.
956 conf_undelim(sc, "=:/.", "=:/.");
959 /* --- Read a sequence of arguments --- */
961 while (sc->t == CTOK_WORD) {
962 dstr_putd(&d, &sc->d); d.len++;
966 conf_undelim(sc, 0, 0);
968 /* --- Expect the closing `]' --- */
971 error(sc, "parse error, missing `]'");
974 /* --- If there are no arguments, whinge --- */
977 error(sc, "must specify at least one argument");
979 /* --- Allocate a lump of memory for the array --- */
981 xa = xmalloc(XARGS_SZ(argc) + d.len);
984 p = (char *)(v + argc + 1);
985 memcpy(p, d.buf, d.len);
990 /* --- Start dumping addresses into the @argv@ array --- */
994 while (*p++ && p < q)
1002 /* --- Do some other setting up --- */
1006 x->xo = CREATE(xopts);
1012 /* --- @exec_endpt@ --- */
1014 static endpt *exec_endpt(xdata *x, const char *desc)
1016 xept *xe = CREATE(xept);
1017 xe->e.ops = &xept_ops;
1021 xe->xa = x->xa; xe->xa->ref++;
1022 xe->xo = x->xo; xe->xo->ref++;
1025 xe->desc = xstrdup(desc);
1029 /* --- @exec_destroy@ --- */
1031 static void exec_destroy(xdata *x)
1033 x_tidy(x->xa, x->xo);
1036 /*----- Source definition -------------------------------------------------*/
1038 /* --- @option@ --- */
1040 static int xsource_option(source *s, scanner *sc)
1042 xsource *xs = (xsource *)s;
1043 return (exec_option(xs ? &xs->x : 0, sc));
1046 /* --- @read@ --- */
1048 static source *xsource_read(scanner *sc)
1052 if (!conf_prefix(sc, "exec"))
1054 xs = CREATE(xsource);
1055 xs->s.ops = &xsource_ops;
1057 exec_read(&xs->x, sc);
1061 /* --- @attach@ --- */
1063 static void xsource_destroy(source */*s*/);
1065 static void xsource_attach(source *s, scanner *sc, target *t)
1067 xsource *xs = (xsource *)s;
1070 /* --- Set up the source description string --- */
1074 exec_desc(&xs->x, &d);
1075 dstr_puts(&d, " -> ");
1076 dstr_puts(&d, t->desc);
1077 xs->s.desc = xstrdup(d.buf);
1081 /* --- Create the endpoints --- */
1083 if ((ee = t->ops->create(t, xs->s.desc)) == 0)
1085 if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) {
1091 /* --- Dispose of source and target --- */
1095 xsource_destroy(&xs->s);
1098 /* --- @destroy@ --- */
1100 static void xsource_destroy(source *s)
1102 xsource *xs = (xsource *)s;
1104 exec_destroy(&xs->x);
1108 /* --- Executable source operations --- */
1110 source_ops xsource_ops = {
1112 xsource_option, xsource_read, xsource_attach, xsource_destroy
1115 /*----- Exec target description -------------------------------------------*/
1117 /* --- @option@ --- */
1119 static int xtarget_option(target *t, scanner *sc)
1121 xtarget *xt = (xtarget *)t;
1122 return (exec_option(xt ? &xt->x : 0, sc));
1125 /* --- @read@ --- */
1127 static target *xtarget_read(scanner *sc)
1132 if (!conf_prefix(sc, "exec"))
1134 xt = CREATE(xtarget);
1135 xt->t.ops = &xtarget_ops;
1136 exec_read(&xt->x, sc);
1137 exec_desc(&xt->x, &d);
1138 xt->t.desc = xstrdup(d.buf);
1143 /* --- @create@ --- */
1145 static endpt *xtarget_create(target *t, const char *desc)
1147 xtarget *xt = (xtarget *)t;
1148 endpt *e = exec_endpt(&xt->x, desc);
1152 /* --- @destroy@ --- */
1154 static void xtarget_destroy(target *t)
1156 xtarget *xt = (xtarget *)t;
1158 exec_destroy(&xt->x);
1162 /* --- Exec target operations --- */
1164 target_ops xtarget_ops = {
1166 xtarget_option, xtarget_read, 0, xtarget_create, xtarget_destroy
1169 /*----- That's all, folks -------------------------------------------------*/