X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=applets%2Fapplets.c;h=bd8cfec5da2356ace2e14c4b57be656cb9f47dc7;hb=eea561871b45a2335ab6a09f14dad627ffcdc1cd;hp=4af569de305ad482045f9ccc863a3b5071ebed0a;hpb=2faee7b1ed84698ae057ac44bdb0a9f686dd945f;p=oweals%2Fbusybox.git diff --git a/applets/applets.c b/applets/applets.c index 4af569de3..bd8cfec5d 100644 --- a/applets/applets.c +++ b/applets/applets.c @@ -6,61 +6,49 @@ * 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 -#include -#include #include -#include "busybox.h" +#include + +#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 #include #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; @@ -69,131 +57,274 @@ struct BB_suid_config 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 + * [::space::]*=[::space::]* + * 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("."); + } + *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) { @@ -212,22 +343,15 @@ check_suid (struct BB_applet *applet) 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 { @@ -243,212 +367,111 @@ check_suid (struct BB_applet *applet) #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, '='); /* [::space::]*=[::space::]* */ + 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 ."); - } else { - struct passwd *pwd; - char *p2 = strchr (p, '.'); - - if (!p2) - parse_error ("parsing ."); - - *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)); + } +}