* isn't something I'm going to worry about... If you wrote something
* here, please feel free to acknowledge your work.
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
* Permission has been granted to redistribute this code under the GPL.
*
+ * Licensed under GPLv2 or later, see file License in this tarball for details.
*/
+#include "busybox.h"
#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
#include <string.h>
-#include "busybox.h"
+#include <assert.h>
+
+#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
+static const char usage_messages[] =
+#define MAKE_USAGE
+#include "usage.h"
+#include "applets.h"
+;
+#undef MAKE_USAGE
+#else
+#define usage_messages 0
+#endif /* ENABLE_SHOW_USAGE */
#undef APPLET
#undef APPLET_NOUSAGE
#undef PROTOTYPES
#include "applets.h"
-struct BB_applet *applet_using;
+static struct BB_applet *applet_using;
/* The -1 arises because of the {0,NULL,0,-1} entry above. */
const size_t NUM_APPLETS = (sizeof (applets) / sizeof (struct BB_applet) - 1);
-#ifdef CONFIG_FEATURE_SUID
-
-static void check_suid (struct BB_applet *app);
-
#ifdef CONFIG_FEATURE_SUID_CONFIG
-#include <sys/stat.h>
#include <ctype.h>
#include "pwd_.h"
#include "grp_.h"
-static int parse_config_file (void);
-
-static int config_ok;
-
#define CONFIG_FILE "/etc/busybox.conf"
/* applets [] is const, so we have to define this "override" structure */
-struct BB_suid_config
+static struct BB_suid_config
{
struct BB_applet *m_applet;
mode_t m_mode;
struct BB_suid_config *m_next;
-};
+} *suid_config;
-static struct BB_suid_config *suid_config;
-
-#endif /* CONFIG_FEATURE_SUID_CONFIG */
-
-#endif /* CONFIG_FEATURE_SUID */
+static int suid_cfg_readable;
+/* check if u is member of group g */
+static int ingroup (uid_t u, gid_t g)
+{
+ struct group *grp = getgrgid (g);
+ if (grp) {
+ char **mem;
-extern void
-bb_show_usage (void)
-{
- const char *format_string;
- const char *usage_string = usage_messages;
- int i;
+ for (mem = grp->gr_mem; *mem; mem++) {
+ struct passwd *pwd = getpwnam (*mem);
- for (i = applet_using - applets; i > 0;) {
- if (!*usage_string++) {
- --i;
+ if (pwd && (pwd->pw_uid == u))
+ return 1;
}
}
-
- format_string = "%s\n\nUsage: %s %s\n\n";
- if (*usage_string == '\b')
- format_string = "%s\n\nNo help available.\n\n";
- fprintf (stderr, format_string, bb_msg_full_version, applet_using->name,
- usage_string);
-
- exit (EXIT_FAILURE);
+ return 0;
}
-static int
-applet_name_compare (const void *x, const void *y)
+/* This should probably be a libbb routine. In that case,
+ * I'd probably rename it to something like bb_trimmed_slice.
+ */
+static char *get_trimmed_slice(char *s, char *e)
{
- const char *name = x;
- const struct BB_applet *applet = y;
+ /* First, consider the value at e to be nul and back up until we
+ * reach a non-space char. Set the char after that (possibly at
+ * the original e) to nul. */
+ while (e-- > s) {
+ if (!isspace(*e)) {
+ break;
+ }
+ }
+ e[1] = 0;
- return strcmp (name, applet->name);
+ /* Next, advance past all leading space and return a ptr to the
+ * first non-space char; possibly the terminating nul. */
+ return skip_whitespace(s);
}
-extern const size_t NUM_APPLETS;
-struct BB_applet *
-find_applet_by_name (const char *name)
-{
- return bsearch (name, applets, NUM_APPLETS, sizeof (struct BB_applet),
- applet_name_compare);
-}
+#define parse_error(x) { err=x; goto pe_label; }
-void
-run_applet_by_name (const char *name, int argc, char **argv)
-{
- static int recurse_level = 0;
- extern int been_there_done_that; /* From busybox.c */
+/* Don't depend on the tools to combine strings. */
+static const char config_file[] = CONFIG_FILE;
-#ifdef CONFIG_FEATURE_SUID_CONFIG
- if (recurse_level == 0)
- config_ok = parse_config_file ();
-#endif
+/* There are 4 chars + 1 nul for each of user/group/other. */
+static const char mode_chars[] = "Ssx-\0Ssx-\0Ttx-";
- recurse_level++;
- /* Do a binary search to find the applet entry given the name. */
- if ((applet_using = find_applet_by_name (name)) != NULL) {
- bb_applet_name = applet_using->name;
- if (argv[1] && strcmp (argv[1], "--help") == 0) {
- if (strcmp (applet_using->name, "busybox") == 0) {
- if (argv[2])
- applet_using = find_applet_by_name (argv[2]);
- else
- applet_using = NULL;
- }
- if (applet_using)
- bb_show_usage ();
- been_there_done_that = 1;
- busybox_main (0, NULL);
+/* We don't supply a value for the nul, so an index adjustment is
+ * necessary below. Also, we use unsigned short here to save some
+ * space even though these are really mode_t values. */
+static const unsigned short mode_mask[] = {
+ /* SST sst xxx --- */
+ S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* user */
+ S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* group */
+ 0, S_IXOTH, S_IXOTH, 0 /* other */
+};
+
+static void parse_config_file(void)
+{
+ struct BB_suid_config *sct_head;
+ struct BB_suid_config *sct;
+ struct BB_applet *applet;
+ FILE *f;
+ char *err;
+ char *s;
+ char *e;
+ int i, lc, section;
+ char buffer[256];
+ struct stat st;
+
+ assert(!suid_config); /* Should be set to NULL by bss init. */
+
+ if ((stat(config_file, &st) != 0) /* No config file? */
+ || !S_ISREG(st.st_mode) /* Not a regular file? */
+ || (st.st_uid != 0) /* Not owned by root? */
+ || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
+ || !(f = fopen(config_file, "r")) /* Can not open? */
+ ) {
+ return;
}
-#ifdef CONFIG_FEATURE_SUID
- check_suid (applet_using);
-#endif
- exit ((*(applet_using->main)) (argc, argv));
- }
- /* Just in case they have renamed busybox - Check argv[1] */
- if (recurse_level == 1) {
- run_applet_by_name ("busybox", argc, argv);
- }
- recurse_level--;
-}
+ suid_cfg_readable = 1;
+ sct_head = NULL;
+ section = lc = 0;
+ do {
+ s = buffer;
-#ifdef CONFIG_FEATURE_SUID
+ if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
+ if (ferror(f)) { /* Make sure it wasn't a read error. */
+ parse_error("reading");
+ }
+ fclose(f);
+ suid_config = sct_head; /* Success, so set the pointer. */
+ return;
+ }
-#ifdef CONFIG_FEATURE_SUID_CONFIG
+ lc++; /* Got a (partial) line. */
+
+ /* If a line is too long for our buffer, we consider it an error.
+ * The following test does mistreat one corner case though.
+ * If the final line of the file does not end with a newline and
+ * yet exactly fills the buffer, it will be treated as too long
+ * even though there isn't really a problem. But it isn't really
+ * worth adding code to deal with such an unlikely situation, and
+ * we do err on the side of caution. Besides, the line would be
+ * too long if it did end with a newline. */
+ if (!strchr(s, '\n') && !feof(f)) {
+ parse_error("line too long");
+ }
-/* check if u is member of group g */
-static int
-ingroup (uid_t u, gid_t g)
-{
- struct group *grp = getgrgid (g);
+ /* Trim leading and trailing whitespace, ignoring comments, and
+ * check if the resulting string is empty. */
+ if (!*(s = get_trimmed_slice(s, strchrnul(s, '#')))) {
+ continue;
+ }
- if (grp) {
- char **mem;
+ /* Check for a section header. */
+
+ if (*s == '[') {
+ /* Unlike the old code, we ignore leading and trailing
+ * whitespace for the section name. We also require that
+ * there are no stray characters after the closing bracket. */
+ if (!(e = strchr(s, ']')) /* Missing right bracket? */
+ || e[1] /* Trailing characters? */
+ || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
+ ) {
+ parse_error("section header");
+ }
+ /* Right now we only have one section so just check it.
+ * If more sections are added in the future, please don't
+ * resort to cascading ifs with multiple strcasecmp calls.
+ * That kind of bloated code is all too common. A loop
+ * and a string table would be a better choice unless the
+ * number of sections is very small. */
+ if (strcasecmp(s, "SUID") == 0) {
+ section = 1;
+ continue;
+ }
+ section = -1; /* Unknown section so set to skip. */
+ continue;
+ }
- for (mem = grp->gr_mem; *mem; mem++) {
- struct passwd *pwd = getpwnam (*mem);
+ /* Process sections. */
- if (pwd && (pwd->pw_uid == u))
- return 1;
+ if (section == 1) { /* SUID */
+ /* Since we trimmed leading and trailing space above, we're
+ * now looking for strings of the form
+ * <key>[::space::]*=[::space::]*<value>
+ * where both key and value could contain inner whitespace. */
+
+ /* First get the key (an applet name in our case). */
+ if (!!(e = strchr(s, '='))) {
+ s = get_trimmed_slice(s, e);
+ }
+ if (!e || !*s) { /* Missing '=' or empty key. */
+ parse_error("keyword");
+ }
+
+ /* Ok, we have an applet name. Process the rhs if this
+ * applet is currently built in and ignore it otherwise.
+ * Note: This can hide config file bugs which only pop
+ * up when the busybox configuration is changed. */
+ if ((applet = find_applet_by_name(s))) {
+ /* Note: We currently don't check for duplicates!
+ * The last config line for each applet will be the
+ * one used since we insert at the head of the list.
+ * I suppose this could be considered a feature. */
+ sct = xmalloc(sizeof(struct BB_suid_config));
+ sct->m_applet = applet;
+ sct->m_mode = 0;
+ sct->m_next = sct_head;
+ sct_head = sct;
+
+ /* Get the specified mode. */
+
+ e = skip_whitespace(e+1);
+
+ for (i=0 ; i < 3 ; i++) {
+ const char *q;
+ if (!*(q = strchrnul(mode_chars + 5*i, *e++))) {
+ parse_error("mode");
+ }
+ /* Adjust by -i to account for nul. */
+ sct->m_mode |= mode_mask[(q - mode_chars) - i];
+ }
+
+ /* Now get the the user/group info. */
+
+ s = skip_whitespace(e);
+
+ /* Note: We require whitespace between the mode and the
+ * user/group info. */
+ if ((s == e) || !(e = strchr(s, '.'))) {
+ parse_error("<uid>.<gid>");
+ }
+ *e++ = 0;
+
+ /* We can't use get_ug_id here since it would exit()
+ * if a uid or gid was not found. Oh well... */
+ {
+ char *e2;
+
+ sct->m_uid = strtoul(s, &e2, 10);
+ if (*e2 || (s == e2)) {
+ struct passwd *pwd;
+ if (!(pwd = getpwnam(s))) {
+ parse_error("user");
+ }
+ sct->m_uid = pwd->pw_uid;
+ }
+
+ sct->m_gid = strtoul(e, &e2, 10);
+ if (*e2 || (e == e2)) {
+ struct group *grp;
+ if (!(grp = getgrnam(e))) {
+ parse_error("group");
+ }
+ sct->m_gid = grp->gr_gid;
+ }
+ }
+ }
+ continue;
+ }
+
+ /* Unknown sections are ignored. */
+
+ /* Encountering configuration lines prior to seeing a
+ * section header is treated as an error. This is how
+ * the old code worked, but it may not be desirable.
+ * We may want to simply ignore such lines in case they
+ * are used in some future version of busybox. */
+ if (!section) {
+ parse_error("keyword outside section");
+ }
+
+ } while (1);
+
+ pe_label:
+ fprintf(stderr, "Parse error in %s, line %d: %s\n",
+ config_file, lc, err);
+
+ fclose(f);
+ /* Release any allocated memory before returning. */
+ while (sct_head) {
+ sct = sct_head->m_next;
+ free(sct_head);
+ sct_head = sct;
}
- }
- return 0;
+ return;
}
-#endif
-
+#else
+#define parse_config_file()
+#endif /* CONFIG_FEATURE_SUID_CONFIG */
-void
-check_suid (struct BB_applet *applet)
+#ifdef CONFIG_FEATURE_SUID
+static void check_suid (struct BB_applet *applet)
{
uid_t ruid = getuid (); /* real [ug]id */
uid_t rgid = getgid ();
#ifdef CONFIG_FEATURE_SUID_CONFIG
- if (config_ok) {
+ if (suid_cfg_readable) {
struct BB_suid_config *sct;
for (sct = suid_config; sct; sct = sct->m_next) {
bb_error_msg_and_die ("You have no permission to run this applet!");
if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { /* *both* have to be set for sgid */
- if (setegid (sct->m_gid))
- bb_error_msg_and_die
- ("BusyBox binary has insufficient rights to set proper GID for applet!");
- } else
- setgid (rgid); /* no sgid -> drop */
-
- if (sct->m_mode & S_ISUID) {
- if (seteuid (sct->m_uid))
- bb_error_msg_and_die
- ("BusyBox binary has insufficient rights to set proper UID for applet!");
- } else
- setuid (ruid); /* no suid -> drop */
+ xsetgid(sct->m_gid);
+ } else xsetgid(rgid); /* no sgid -> drop */
+
+ if (sct->m_mode & S_ISUID) xsetuid(sct->m_uid);
+ else xsetuid(ruid); /* no suid -> drop */
} else {
- /* default: drop all priviledges */
- setgid (rgid);
- setuid (ruid);
+ /* default: drop all privileges */
+ xsetgid(rgid);
+ xsetuid(ruid);
}
return;
} else {
#endif
if (applet->need_suid == _BB_SUID_ALWAYS) {
- if (geteuid () != 0)
- bb_error_msg_and_die ("This applet requires root priviledges!");
+ if (geteuid()) bb_error_msg_and_die("Applet requires root privileges!");
} else if (applet->need_suid == _BB_SUID_NEVER) {
- setgid (rgid); /* drop all priviledges */
- setuid (ruid);
+ xsetgid(rgid); /* drop all privileges */
+ xsetuid(ruid);
}
}
+#else
+#define check_suid(x)
+#endif /* CONFIG_FEATURE_SUID */
-#ifdef CONFIG_FEATURE_SUID_CONFIG
-#define parse_error(x) { err=x; goto pe_label; }
+#if ENABLE_FEATURE_COMPRESS_USAGE
+#include "usage_compressed.h"
+#include "unarchive.h"
-int
-parse_config_file (void)
+static const char *unpack_usage_messages(void)
{
- struct stat st;
- char *err = 0;
- FILE *f = 0;
- int lc = 0;
-
- suid_config = 0;
-
- /* is there a config file ? */
- if (stat (CONFIG_FILE, &st) == 0) {
- /* is it owned by root with no write perm. for group and others ? */
- if (S_ISREG (st.st_mode) && (st.st_uid == 0)
- && (!(st.st_mode & (S_IWGRP | S_IWOTH)))) {
- /* that's ok .. then try to open it */
- f = fopen (CONFIG_FILE, "r");
-
- if (f) {
- char buffer[256];
- int section = 0;
-
- while (fgets (buffer, sizeof (buffer) - 1, f)) {
- char c = buffer[0];
- char *p;
-
- lc++;
-
- p = strchr (buffer, '#');
- if (p)
- *p = 0;
- p = buffer + bb_strlen (buffer);
- while ((p > buffer) && isspace (*--p))
- *p = 0;
-
- if (p == buffer)
- continue;
-
- if (c == '[') {
- p = strchr (buffer, ']');
-
- if (!p || (p == (buffer + 1))) /* no matching ] or empty [] */
- parse_error ("malformed section header");
-
- *p = 0;
-
- if (strcasecmp (buffer + 1, "SUID") == 0)
- section = 1;
- else
- section = -1; /* unknown section - just skip */
- } else if (section) {
- switch (section) {
- case 1:{ /* SUID */
- int l;
- struct BB_applet *applet;
-
- p = strchr (buffer, '='); /* <key>[::space::]*=[::space::]*<value> */
+ int input[2], output[2], pid;
+ char *buf;
+
+ if(pipe(input) < 0 || pipe(output) < 0)
+ exit(1);
+
+ pid = fork();
+ switch (pid) {
+ case -1: /* error */
+ exit(1);
+ case 0: /* child */
+ close(input[1]);
+ close(output[0]);
+ uncompressStream(input[0], output[1]);
+ exit(0);
+ }
+ /* parent */
+
+ close(input[0]);
+ close(output[1]);
+ pid = fork();
+ switch (pid) {
+ case -1: /* error */
+ exit(1);
+ case 0: /* child */
+ full_write(input[1], packed_usage, sizeof(packed_usage));
+ exit(0);
+ }
+ /* parent */
+ close(input[1]);
- if (!p || (p == (buffer + 1))) /* no = or key is empty */
- parse_error ("malformed keyword");
+ buf = xmalloc(SIZEOF_usage_messages);
+ full_read(output[0], buf, SIZEOF_usage_messages);
+ return buf;
+}
- l = p - buffer;
- while (isspace (buffer[--l])) {
- /* skip whitespace */
- }
+#else
+#define unpack_usage_messages() usage_messages
+#endif /* ENABLE_FEATURE_COMPRESS_USAGE */
- buffer[l + 1] = 0;
-
- if ((applet = find_applet_by_name (buffer))) {
- struct BB_suid_config *sct =
- xmalloc (sizeof (struct BB_suid_config));
-
- sct->m_applet = applet;
- sct->m_next = suid_config;
- suid_config = sct;
-
- while (isspace (*++p)) {
- /* skip whitespace */
- }
-
- sct->m_mode = 0;
-
- switch (*p++) {
- case 'S':
- sct->m_mode |= S_ISUID;
- break;
- case 's':
- sct->m_mode |= S_ISUID;
- /* no break */
- case 'x':
- sct->m_mode |= S_IXUSR;
- break;
- case '-':
- break;
- default:
- parse_error ("invalid user mode");
- }
-
- switch (*p++) {
- case 's':
- sct->m_mode |= S_ISGID;
- /* no break */
- case 'x':
- sct->m_mode |= S_IXGRP;
- break;
- case 'S':
- break;
- case '-':
- break;
- default:
- parse_error ("invalid group mode");
- }
-
- switch (*p) {
- case 't':
- case 'x':
- sct->m_mode |= S_IXOTH;
- break;
- case 'T':
- case '-':
- break;
- default:
- parse_error ("invalid other mode");
- }
-
- while (isspace (*++p)) {
- /* skip whitespace */
- }
-
- if (isdigit (*p)) {
- sct->m_uid = strtol (p, &p, 10);
- if (*p++ != '.')
- parse_error ("parsing <uid>.<gid>");
- } else {
- struct passwd *pwd;
- char *p2 = strchr (p, '.');
-
- if (!p2)
- parse_error ("parsing <uid>.<gid>");
-
- *p2 = 0;
- pwd = getpwnam (p);
-
- if (!pwd)
- parse_error ("invalid user name");
-
- sct->m_uid = pwd->pw_uid;
- p = p2 + 1;
- }
- if (isdigit (*p))
- sct->m_gid = strtol (p, &p, 10);
- else {
- struct group *grp = getgrnam (p);
-
- if (!grp)
- parse_error ("invalid group name");
-
- sct->m_gid = grp->gr_gid;
- }
- }
- break;
- }
- default: /* unknown - skip */
- break;
- }
- } else
- parse_error ("keyword not within section");
- }
- fclose (f);
- return 1;
- }
+void bb_show_usage (void)
+{
+ if (ENABLE_SHOW_USAGE) {
+ const char *format_string;
+ const char *usage_string = unpack_usage_messages();
+ int i;
+
+ for (i = applet_using - applets; i > 0;)
+ if (!*usage_string++) --i;
+
+ format_string = "%s\n\nUsage: %s %s\n\n";
+ if (*usage_string == '\b')
+ format_string = "%s\n\nNo help available.\n\n";
+ fprintf (stderr, format_string, bb_msg_full_version,
+ applet_using->name, usage_string);
}
- }
- return 0; /* no config file or not readable (not an error) */
-pe_label:
- fprintf (stderr, "Parse error in %s, line %d: %s\n", CONFIG_FILE, lc, err);
+ exit (bb_default_error_retval);
+}
- if (f)
- fclose (f);
- return 0;
+static int applet_name_compare(const void *name, const void *vapplet)
+{
+ const struct BB_applet *applet = vapplet;
+
+ return strcmp(name, applet->name);
}
-#endif
+extern const size_t NUM_APPLETS;
-#endif
+struct BB_applet *find_applet_by_name(const char *name)
+{
+ return bsearch(name, applets, NUM_APPLETS, sizeof(struct BB_applet),
+ applet_name_compare);
+}
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+void run_applet_by_name(const char *name, int argc, char **argv)
+{
+ if (ENABLE_FEATURE_SUID_CONFIG) parse_config_file();
+
+ if (!strncmp(name, "busybox", 7)) busybox_main(argc, argv);
+ /* Do a binary search to find the applet entry given the name. */
+ applet_using = find_applet_by_name(name);
+ if (applet_using) {
+ bb_applet_name = applet_using->name;
+ if(argc==2 && !strcmp(argv[1], "--help")) bb_show_usage();
+ if(ENABLE_FEATURE_SUID) check_suid(applet_using);
+ exit((*(applet_using->main))(argc, argv));
+ }
+}
projects / oweals / busybox.git / blobdiff