X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=applets%2Fapplets.c;h=82a7eeea10fdc06f44bf8b3fe1ee24bc47c425e1;hb=f7fcca4af7593218f2185e69715ab3ae16c6cf29;hp=aea116add254897338d32ae204b699528d00eeda;hpb=e15d7573a1263fb364d1678c3a46be47a8b5e5ea;p=oweals%2Fbusybox.git diff --git a/applets/applets.c b/applets/applets.c index aea116add..82a7eeea1 100644 --- a/applets/applets.c +++ b/applets/applets.c @@ -12,15 +12,28 @@ * Licensed under GPLv2 or later, see file License in this tarball for details. */ -#include "busybox.h" -#include -#include -#include -#include #include +#include "busybox.h" + +/* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */ +#if ENABLE_STATIC && defined(__GLIBC__) && !defined(__UCLIBC__) +#warning Static linking against glibc produces buggy executables +#warning (glibc does not cope well with ld --gc-sections). +#warning See sources.redhat.com/bugzilla/show_bug.cgi?id=3400 +#warning Note that glibc is unsuitable for static linking anyway. +#warning If you still want to do it, remove -Wl,--gc-sections +#warning from top-level Makefile and remove this warning. +#endif + + +/* Declare _main() */ +#define PROTOTYPES +#include "applets.h" +#undef PROTOTYPES #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE -static const char usage_messages[] = +/* Define usage_messages[] */ +static const char usage_messages[] = "" #define MAKE_USAGE #include "usage.h" #include "applets.h" @@ -28,58 +41,51 @@ static const char usage_messages[] = #undef MAKE_USAGE #else #define usage_messages 0 -#endif /* ENABLE_SHOW_USAGE */ +#endif /* SHOW_USAGE */ -#undef APPLET -#undef APPLET_NOUSAGE -#undef PROTOTYPES +/* Define struct bb_applet applets[] */ #include "applets.h" +/* The -1 arises because of the {0,NULL,0,-1} entry. */ +const unsigned short NUM_APPLETS = sizeof(applets) / sizeof(applets[0]) - 1; -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_CONFIG - -#include -#include -#include "pwd_.h" -#include "grp_.h" +const struct bb_applet *current_applet; +const char *applet_name ATTRIBUTE_EXTERNALLY_VISIBLE; +#if !BB_MMU +bool re_execed; +#endif -#define CONFIG_FILE "/etc/busybox.conf" -/* applets [] is const, so we have to define this "override" structure */ -static struct BB_suid_config -{ - struct BB_applet *m_applet; - uid_t m_uid; - gid_t m_gid; - mode_t m_mode; +#if ENABLE_FEATURE_SUID_CONFIG - struct BB_suid_config *m_next; +/* applets[] is const, so we have to define this "override" structure */ +static struct BB_suid_config { + const struct bb_applet *m_applet; + uid_t m_uid; + gid_t m_gid; + mode_t m_mode; + struct BB_suid_config *m_next; } *suid_config; -static int suid_cfg_readable; +static bool suid_cfg_readable; /* check if u is member of group g */ -static int ingroup (uid_t u, gid_t g) +static int ingroup(uid_t u, gid_t g) { - struct group *grp = getgrgid (g); + struct group *grp = getgrgid(g); - if (grp) { - char **mem; + if (grp) { + char **mem; - for (mem = grp->gr_mem; *mem; mem++) { - struct passwd *pwd = getpwnam (*mem); + for (mem = grp->gr_mem; *mem; mem++) { + struct passwd *pwd = getpwnam(*mem); - if (pwd && (pwd->pw_uid == u)) - return 1; + if (pwd && (pwd->pw_uid == u)) + return 1; + } } - } - return 0; + return 0; } /* This should probably be a libbb routine. In that case, @@ -95,18 +101,15 @@ static char *get_trimmed_slice(char *s, char *e) break; } } - e[1] = 0; + e[1] = '\0'; /* Next, advance past all leading space and return a ptr to the * first non-space char; possibly the terminating nul. */ - return (char *) bb_skip_whitespace(s); + return skip_whitespace(s); } - -#define parse_error(x) { err=x; goto pe_label; } - /* Don't depend on the tools to combine strings. */ -static const char config_file[] = CONFIG_FILE; +static const char config_file[] = "/etc/busybox.conf"; /* There are 4 chars + 1 nul for each of user/group/other. */ static const char mode_chars[] = "Ssx-\0Ssx-\0Ttx-"; @@ -115,33 +118,37 @@ static const char mode_chars[] = "Ssx-\0Ssx-\0Ttx-"; * 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 --- */ + /* 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 */ }; +#define parse_error(x) do { errmsg = x; goto pe_label; } while (0) + static void parse_config_file(void) { struct BB_suid_config *sct_head; struct BB_suid_config *sct; - struct BB_applet *applet; + const struct bb_applet *applet; FILE *f; - char *err; + const char *errmsg; char *s; char *e; - int i, lc, section; + int i; + unsigned lc; + smallint section; char buffer[256]; struct stat st; - assert(!suid_config); /* Should be set to NULL by bss init. */ + 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? */ - ) { + 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")) /* Cannot open? */ + ) { return; } @@ -149,7 +156,7 @@ static void parse_config_file(void) sct_head = NULL; section = lc = 0; - do { + while (1) { s = buffer; if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */ @@ -177,7 +184,8 @@ static void parse_config_file(void) /* Trim leading and trailing whitespace, ignoring comments, and * check if the resulting string is empty. */ - if (!*(s = get_trimmed_slice(s, strchrnul(s, '#')))) { + s = get_trimmed_slice(s, strchrnul(s, '#')); + if (!*s) { continue; } @@ -187,10 +195,11 @@ static void parse_config_file(void) /* 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? */ - ) { + e = strchr(s, ']'); + if (!e /* 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. @@ -216,7 +225,8 @@ static void parse_config_file(void) * where both key and value could contain inner whitespace. */ /* First get the key (an applet name in our case). */ - if (!!(e = strchr(s, '='))) { + e = strchr(s, '='); + if (e) { s = get_trimmed_slice(s, e); } if (!e || !*s) { /* Missing '=' or empty key. */ @@ -225,9 +235,10 @@ static void parse_config_file(void) /* 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 + * Note: this can hide config file bugs which only pop * up when the busybox configuration is changed. */ - if ((applet = find_applet_by_name(s))) { + applet = find_applet_by_name(s); + if (applet) { /* 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. @@ -240,11 +251,12 @@ static void parse_config_file(void) /* Get the specified mode. */ - e = (char *) bb_skip_whitespace(e+1); + e = skip_whitespace(e+1); - for (i=0 ; i < 3 ; i++) { + for (i = 0; i < 3; i++) { const char *q; - if (!*(q = strchrnul(mode_chars + 5*i, *e++))) { + q = strchrnul(mode_chars + 5*i, *e++); + if (!*q) { parse_error("mode"); } /* Adjust by -i to account for nul. */ @@ -253,37 +265,34 @@ static void parse_config_file(void) /* Now get the the user/group info. */ - s = (char *) bb_skip_whitespace(e); + s = skip_whitespace(e); - /* Note: We require whitespace between the mode and the + /* Note: we require whitespace between the mode and the * user/group info. */ if ((s == e) || !(e = strchr(s, '.'))) { parse_error("."); } - *e++ = 0; + *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_uid = bb_strtoul(s, NULL, 10); + if (errno) { + struct passwd *pwd = getpwnam(s); + if (!pwd) { + 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; + sct->m_gid = bb_strtoul(e, NULL, 10); + if (errno) { + struct group *grp; + grp = getgrnam(e); + if (!grp) { + parse_error("group"); } + sct->m_gid = grp->gr_gid; } } continue; @@ -300,11 +309,11 @@ static void parse_config_file(void) parse_error("keyword outside section"); } - } while (1); + } /* while (1) */ pe_label: fprintf(stderr, "Parse error in %s, line %d: %s\n", - config_file, lc, err); + config_file, lc, errmsg); fclose(f); /* Release any allocated memory before returning. */ @@ -313,81 +322,78 @@ static void parse_config_file(void) free(sct_head); sct_head = sct; } - return; } - #else -#define parse_config_file() -#endif /* CONFIG_FEATURE_SUID_CONFIG */ +#define parse_config_file() ((void)0) +#endif /* FEATURE_SUID_CONFIG */ + -#ifdef CONFIG_FEATURE_SUID -static void check_suid (struct BB_applet *applet) +#if ENABLE_FEATURE_SUID +static void check_suid(const struct bb_applet *applet) { - uid_t ruid = getuid (); /* real [ug]id */ - uid_t rgid = getgid (); + uid_t ruid = getuid(); /* real [ug]id */ + uid_t rgid = getgid(); -#ifdef CONFIG_FEATURE_SUID_CONFIG - if (suid_cfg_readable) { - struct BB_suid_config *sct; +#if ENABLE_FEATURE_SUID_CONFIG + if (suid_cfg_readable) { + struct BB_suid_config *sct; + mode_t m; - for (sct = suid_config; sct; sct = sct->m_next) { - if (sct->m_applet == applet) - break; - } - if (sct) { - mode_t m = sct->m_mode; - - if (sct->m_uid == ruid) /* same uid */ - m >>= 6; - else if ((sct->m_gid == rgid) || ingroup (ruid, sct->m_gid)) /* same group / in group */ - m >>= 3; - - if (!(m & S_IXOTH)) /* is x bit not set ? */ - 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 */ - } else { + for (sct = suid_config; sct; sct = sct->m_next) { + if (sct->m_applet == applet) + goto found; + } /* default: drop all privileges */ - setgid (rgid); - setuid (ruid); + xsetgid(rgid); + xsetuid(ruid); + return; + found: + m = sct->m_mode; + if (sct->m_uid == ruid) + /* same uid */ + m >>= 6; + else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid)) + /* same group / in group */ + m >>= 3; + + if (!(m & S_IXOTH)) /* is x bit not set ? */ + bb_error_msg_and_die("you have no permission to run this applet!"); + + if (sct->m_gid != 0) { + /* _both_ have to be set for sgid */ + if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { + xsetgid(sct->m_gid); + } else xsetgid(rgid); /* no sgid -> drop */ + } + if (sct->m_uid != 0) { + if (sct->m_mode & S_ISUID) xsetuid(sct->m_uid); + else xsetuid(ruid); /* no suid -> drop */ + } + return; } - return; - } else { -#ifndef CONFIG_FEATURE_SUID_CONFIG_QUIET - static int onetime = 0; - - if (!onetime) { - onetime = 1; - fprintf (stderr, "Using fallback suid method\n"); +#if !ENABLE_FEATURE_SUID_CONFIG_QUIET + { + static bool onetime = 0; + + if (!onetime) { + onetime = 1; + fprintf(stderr, "Using fallback suid method\n"); + } } #endif - } #endif - if (applet->need_suid == _BB_SUID_ALWAYS) { - if (geteuid () != 0) - bb_error_msg_and_die ("This applet requires root privileges!"); - } else if (applet->need_suid == _BB_SUID_NEVER) { - setgid (rgid); /* drop all privileges */ - setuid (ruid); - } + if (applet->need_suid == _BB_SUID_ALWAYS) { + if (geteuid()) + bb_error_msg_and_die("applet requires root privileges!"); + } else if (applet->need_suid == _BB_SUID_NEVER) { + xsetgid(rgid); /* drop all privileges */ + xsetuid(ruid); + } } #else -#define check_suid(x) -#endif /* CONFIG_FEATURE_SUID */ - +#define check_suid(x) ((void)0) +#endif /* FEATURE_SUID */ #if ENABLE_FEATURE_COMPRESS_USAGE @@ -397,93 +403,240 @@ static void check_suid (struct BB_applet *applet) static const char *unpack_usage_messages(void) { - 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); + char *outbuf = NULL; + bunzip_data *bd; + int i; + + i = start_bunzip(&bd, + /* src_fd: */ -1, + /* inbuf: */ packed_usage, + /* len: */ sizeof(packed_usage)); + /* read_bunzip can longjmp to start_bunzip, and ultimately + * end up here with i != 0 on read data errors! Not trivial */ + if (!i) { + /* Cannot use xmalloc: will leak bd in NOFORK case! */ + outbuf = malloc_or_warn(SIZEOF_usage_messages); + if (outbuf) + read_bunzip(bd, outbuf, SIZEOF_usage_messages); } - /* parent */ - - close(input[0]); - close(output[1]); - pid = fork(); - switch (pid) { - case -1: /* error */ - exit(1); - case 0: /* child */ - bb_full_write(input[1], packed_usage, sizeof(packed_usage)); - exit(0); - } - /* parent */ - close(input[1]); - - buf = xmalloc(SIZEOF_usage_messages); - bb_full_read(output[0], buf, SIZEOF_usage_messages); - return buf; + dealloc_bunzip(bd); + return outbuf; } +#define dealloc_usage_messages(s) free(s) #else + #define unpack_usage_messages() usage_messages -#endif /* ENABLE_FEATURE_COMPRESS_USAGE */ +#define dealloc_usage_messages(s) ((void)(s)) + +#endif /* FEATURE_COMPRESS_USAGE */ + -void bb_show_usage (void) +void bb_show_usage(void) { if (ENABLE_SHOW_USAGE) { const char *format_string; - const char *usage_string = unpack_usage_messages(); + const char *p; + const char *usage_string = p = unpack_usage_messages(); int i; - for (i = applet_using - applets; i > 0;) - if (!*usage_string++) --i; + i = current_applet - applets; + while (i) { + while (*p++) continue; + i--; + } format_string = "%s\n\nUsage: %s %s\n\n"; - if (*usage_string == '\b') + if (*p == '\b') format_string = "%s\n\nNo help available.\n\n"; - fprintf (stderr, format_string, bb_msg_full_version, - applet_using->name, usage_string); + fprintf(stderr, format_string, bb_msg_full_version, + applet_name, p); + dealloc_usage_messages((char*)usage_string); } + xfunc_die(); +} - exit (bb_default_error_retval); + +static int applet_name_compare(const void *name, const void *vapplet) +{ + const struct bb_applet *applet = vapplet; + + return strcmp(name, applet->name); +} + +const struct bb_applet *find_applet_by_name(const char *name) +{ + /* Do a binary search to find the applet entry given the name. */ + return bsearch(name, applets, NUM_APPLETS, sizeof(applets[0]), + applet_name_compare); +} + + +#if ENABLE_FEATURE_INSTALLER +/* create (sym)links for each applet */ +static void install_links(const char *busybox, int use_symbolic_links) +{ + /* directory table + * this should be consistent w/ the enum, + * busybox.h::bb_install_loc_t, or else... */ + static const char usr_bin [] = "/usr/bin"; + static const char usr_sbin[] = "/usr/sbin"; + static const char *const install_dir[] = { + &usr_bin [8], /* "", equivalent to "/" for concat_path_file() */ + &usr_bin [4], /* "/bin" */ + &usr_sbin[4], /* "/sbin" */ + usr_bin, + usr_sbin + }; + + int (*lf)(const char *, const char *) = link; + char *fpc; + int i; + int rc; + + if (use_symbolic_links) + lf = symlink; + + for (i = 0; applets[i].name != NULL; i++) { + fpc = concat_path_file( + install_dir[applets[i].install_loc], + applets[i].name); + rc = lf(busybox, fpc); + if (rc != 0 && errno != EEXIST) { + bb_perror_msg("%s", fpc); + } + free(fpc); + } } +#else +#define install_links(x,y) ((void)0) +#endif /* FEATURE_INSTALLER */ + -static int applet_name_compare (const void *x, const void *y) +/* If we were called as "busybox..." */ +static int busybox_main(int argc, char **argv) { - const char *name = x; - const struct BB_applet *applet = y; + if (ENABLE_FEATURE_INSTALLER && argc > 1 && !strcmp(argv[1], "--install")) { + int use_symbolic_links = 0; + char *busybox; + + /* to use symlinks, or not to use symlinks... */ + if (argc > 2) + if (strcmp(argv[2], "-s") == 0) + use_symbolic_links = 1; + + /* link */ + busybox = xmalloc_readlink_or_warn("/proc/self/exe"); + if (!busybox) + return 1; + install_links(busybox, use_symbolic_links); + if (ENABLE_FEATURE_CLEAN_UP) + free(busybox); + return 0; + } - return strcmp (name, applet->name); + /* Deal with --help. Also print help when called with no arguments */ + + if (argc == 1 || !strcmp(argv[1], "--help") ) { + if (argc > 2) { + /* set name for proper ": applet not found" */ + applet_name = argv[2]; + run_applet_and_exit(applet_name, 2, argv); + } else { + const struct bb_applet *a; + int col, output_width; + + output_width = 80 - sizeof("start-stop-daemon, ") - 8; + if (ENABLE_FEATURE_AUTOWIDTH) { + /* Obtain the terminal width. */ + get_terminal_width_height(0, &output_width, NULL); + /* leading tab and room to wrap */ + output_width -= sizeof("start-stop-daemon, ") + 8; + } + + printf("%s\n" + "Copyright (C) 1998-2006  Erik Andersen, Rob Landley, and others.\n" + "Licensed under GPLv2.  See source distribution for full notice.\n" + "\n" + "Usage: busybox [function] [arguments]...\n" + " or: [function] [arguments]...\n" + "\n" + "\tBusyBox is a multi-call binary that combines many common Unix\n" + "\tutilities into a single executable. Most people will create a\n" + "\tlink to busybox for each function they wish to use and BusyBox\n" + "\twill act like whatever it was invoked as!\n" + "\nCurrently defined functions:\n", bb_msg_full_version); + col = 0; + a = applets; + while (a->name) { + col += printf("%s%s", (col ? ", " : "\t"), a->name); + a++; + if (col > output_width && a->name) { + puts(","); + col = 0; + } + } + puts("\n"); + return 0; + } + } else { + /* we want ": applet not found", not "busybox: ..." */ + applet_name = argv[1]; + run_applet_and_exit(argv[1], argc - 1, argv + 1); + } + + bb_error_msg_and_die("applet not found"); } -extern const size_t NUM_APPLETS; +void run_current_applet_and_exit(int argc, char **argv) +{ + /* Reinit some shared global data */ + optind = 1; + xfunc_error_retval = EXIT_FAILURE; + + applet_name = current_applet->name; + if (argc == 2 && !strcmp(argv[1], "--help")) + bb_show_usage(); + if (ENABLE_FEATURE_SUID) + check_suid(current_applet); + exit(current_applet->main(argc, argv)); +} -struct BB_applet *find_applet_by_name (const char *name) +void run_applet_and_exit(const char *name, int argc, char **argv) { - return bsearch (name, applets, NUM_APPLETS, sizeof (struct BB_applet), - applet_name_compare); + current_applet = find_applet_by_name(name); + if (current_applet) + run_current_applet_and_exit(argc, argv); + if (!strncmp(name, "busybox", 7)) + exit(busybox_main(argc, argv)); } -void run_applet_by_name (const char *name, int argc, char **argv) + +int main(int argc, char **argv) { - if(ENABLE_FEATURE_SUID_CONFIG) parse_config_file (); + const char *s; - 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)); +#if !BB_MMU + /* NOMMU re-exec trick sets high-order bit in first byte of name */ + if (argv[0][0] & 0x80) { + re_execed = 1; + argv[0][0] &= 0x7f; } +#endif + applet_name = argv[0]; + if (applet_name[0] == '-') + applet_name++; + s = strrchr(applet_name, '/'); + if (s) + applet_name = s + 1; + + if (ENABLE_FEATURE_SUID_CONFIG) + parse_config_file(); + + /* Set locale for everybody except 'init' */ + if (ENABLE_LOCALE_SUPPORT && getpid() != 1) + setlocale(LC_ALL, ""); + + run_applet_and_exit(applet_name, argc, argv); + bb_error_msg_and_die("applet not found"); }