libarchive: open_zipped() does not need to check extensions for e.g. gzip
[oweals/busybox.git] / libbb / appletlib.c
index 03f712821e871588cc84c3f1033a9da001987f54..8f3a8a10b6f3027d52d1ce3308885090ce6444f5 100644 (file)
  * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
  */
 #include "busybox.h"
-#include <assert.h>
+
 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
-        || defined(__APPLE__) \
+    || defined(__APPLE__) \
     )
 # include <malloc.h> /* for mallopt */
 #endif
-/* Try to pull in PAGE_SIZE */
-#ifdef __linux__
-# include <sys/user.h>
-#endif
-#ifdef __GNU__ /* Hurd */
-# include <mach/vm_param.h>
-#endif
 
 
 /* Declare <applet>_main() */
@@ -47,7 +40,6 @@
 #include "applets.h"
 #undef PROTOTYPES
 
-
 /* Include generated applet names, pointers to <applet>_main, etc */
 #include "applet_tables.h"
 /* ...and if applet_tables generator says we have only one applet... */
@@ -58,9 +50,9 @@
 # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
 #endif
 
-
 #include "usage_compressed.h"
 
+
 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
 #else
@@ -70,7 +62,7 @@ static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
 #if ENABLE_FEATURE_COMPRESS_USAGE
 
 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
-# include "archive.h"
+# include "bb_archive.h"
 static const char *unpack_usage_messages(void)
 {
        char *outbuf = NULL;
@@ -148,10 +140,9 @@ void FAST_FUNC bb_show_usage(void)
 }
 
 #if NUM_APPLETS > 8
-/* NB: any char pointer will work as well, not necessarily applet_names */
-static int applet_name_compare(const void *name, const void *v)
+static int applet_name_compare(const void *name, const void *idx)
 {
-       int i = (const char *)v - applet_names;
+       int i = (int)(ptrdiff_t)idx - 1;
        return strcmp(name, APPLET_NAME(i));
 }
 #endif
@@ -160,10 +151,12 @@ int FAST_FUNC find_applet_by_name(const char *name)
 #if NUM_APPLETS > 8
        /* Do a binary search to find the applet entry given the name. */
        const char *p;
-       p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
-       if (!p)
-               return -1;
-       return p - applet_names;
+       p = bsearch(name, (void*)(ptrdiff_t)1, ARRAY_SIZE(applet_main), 1, applet_name_compare);
+       /*
+        * if (!p) return -1;
+        * ^^^^^^^^^^^^^^^^^^ the code below will do this if p == NULL :)
+        */
+       return (int)(ptrdiff_t)p - 1;
 #else
        /* A version which does not pull in bsearch */
        int i = 0;
@@ -233,12 +226,12 @@ IF_FEATURE_SUID(static uid_t ruid;)  /* real uid */
 
 # if ENABLE_FEATURE_SUID_CONFIG
 
-/* applets[] is const, so we have to define this "override" structure */
-static struct BB_suid_config {
-       int m_applet;
+static struct suid_config_t {
+       /* next ptr must be first: this struct needs to be llist-compatible */
+       struct suid_config_t *m_next;
        struct bb_uidgid_t m_ugid;
+       int m_applet;
        mode_t m_mode;
-       struct BB_suid_config *m_next;
 } *suid_config;
 
 static bool suid_cfg_readable;
@@ -247,13 +240,10 @@ static bool suid_cfg_readable;
 static int ingroup(uid_t u, gid_t g)
 {
        struct group *grp = getgrgid(g);
-
        if (grp) {
                char **mem;
-
                for (mem = grp->gr_mem; *mem; mem++) {
                        struct passwd *pwd = getpwnam(*mem);
-
                        if (pwd && (pwd->pw_uid == u))
                                return 1;
                }
@@ -261,9 +251,7 @@ static int ingroup(uid_t u, gid_t g)
        return 0;
 }
 
-/* This should probably be a libbb routine.  In that case,
- * I'd probably rename it to something like bb_trimmed_slice.
- */
+/* libbb candidate */
 static char *get_trimmed_slice(char *s, char *e)
 {
        /* First, consider the value at e to be nul and back up until we
@@ -281,32 +269,17 @@ static char *get_trimmed_slice(char *s, char *e)
        return skip_whitespace(s);
 }
 
-/* Don't depend on the tools to combine strings. */
-static const char config_file[] ALIGN1 = "/etc/busybox.conf";
-
-/* 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[] ALIGN2 = {
-       /*  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;
+       /* Don't depend on the tools to combine strings. */
+       static const char config_file[] ALIGN1 = "/etc/busybox.conf";
+
+       struct suid_config_t *sct_head;
        int applet_no;
        FILE *f;
        const char *errmsg;
-       char *s;
-       char *e;
-       int i;
        unsigned lc;
        smallint section;
-       char buffer[256];
        struct stat st;
 
        ruid = getuid();
@@ -327,9 +300,10 @@ static void parse_config_file(void)
        section = lc = 0;
 
        while (1) {
-               s = buffer;
+               char buffer[256];
+               char *s;
 
-               if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
+               if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
                        // Looks like bloat
                        //if (ferror(f)) {   /* Make sure it wasn't a read error. */
                        //      errmsg = "reading";
@@ -340,6 +314,7 @@ static void parse_config_file(void)
                        return;
                }
 
+               s = buffer;
                lc++;                                   /* Got a (partial) line. */
 
                /* If a line is too long for our buffer, we consider it an error.
@@ -368,7 +343,7 @@ 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. */
-                       e = strchr(s, ']');
+                       char *e = strchr(s, ']');
                        if (!e   /* Missing right bracket? */
                         || e[1] /* Trailing characters? */
                         || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
@@ -399,7 +374,7 @@ 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). */
-                       e = strchr(s, '=');
+                       char *e = strchr(s, '=');
                        if (e) {
                                s = get_trimmed_slice(s, e);
                        }
@@ -414,6 +389,9 @@ static void parse_config_file(void)
                         * up when the busybox configuration is changed. */
                        applet_no = find_applet_by_name(s);
                        if (applet_no >= 0) {
+                               unsigned i;
+                               struct suid_config_t *sct;
+
                                /* 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.
@@ -429,34 +407,41 @@ static void parse_config_file(void)
                                e = skip_whitespace(e+1);
 
                                for (i = 0; i < 3; i++) {
-                                       /* There are 4 chars + 1 nul for each of user/group/other. */
-                                       static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
-
-                                       const char *q;
-                                       q = strchrnul(mode_chars + 5*i, *e++);
-                                       if (!*q) {
+                                       /* There are 4 chars for each of user/group/other.
+                                        * "x-xx" instead of "x-" are to make
+                                        * "idx > 3" check catch invalid chars.
+                                        */
+                                       static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
+                                       static const unsigned short mode_mask[] ALIGN2 = {
+                                               S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
+                                               S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
+                                                                         S_IXOTH, 0  /*   x- */
+                                       };
+                                       const char *q = strchrnul(mode_chars + 4*i, *e);
+                                       unsigned idx = q - (mode_chars + 4*i);
+                                       if (idx > 3) {
                                                errmsg = "mode";
                                                goto pe_label;
                                        }
-                                       /* Adjust by -i to account for nul. */
-                                       sct->m_mode |= mode_mask[(q - mode_chars) - i];
+                                       sct->m_mode |= mode_mask[q - mode_chars];
+                                       e++;
                                }
 
                                /* Now get 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, '.'))) {
-                                       errmsg = "uid.gid";
-                                       goto pe_label;
-                               }
-
-                               *e++ = ':'; /* get_uidgid doesn't understand user.group */
-                               if (get_uidgid(&sct->m_ugid, s, /*allow_numeric:*/ 1) == 0) {
-                                       errmsg = "unknown user/group";
-                                       goto pe_label;
+                               /* Default is 0.0, else parse USER.GROUP: */
+                               if (*s) {
+                                       /* We require whitespace between mode and USER.GROUP */
+                                       if ((s == e) || !(e = strchr(s, '.'))) {
+                                               errmsg = "uid.gid";
+                                               goto pe_label;
+                                       }
+                                       *e = ':'; /* get_uidgid needs USER:GROUP syntax */
+                                       if (get_uidgid(&sct->m_ugid, s, /*allow_numeric:*/ 1) == 0) {
+                                               errmsg = "unknown user/group";
+                                               goto pe_label;
+                                       }
                                }
                        }
                        continue;
@@ -477,15 +462,11 @@ static void parse_config_file(void)
        } /* while (1) */
 
  pe_label:
+       fclose(f);
        bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
 
-       fclose(f);
        /* Release any allocated memory before returning. */
-       while (sct_head) {
-               sct = sct_head->m_next;
-               free(sct_head);
-               sct_head = sct;
-       }
+       llist_free((llist_t*)sct_head, NULL);
 }
 # else
 static inline void parse_config_file(void)
@@ -507,7 +488,7 @@ static void check_suid(int applet_no)
 #  if ENABLE_FEATURE_SUID_CONFIG
        if (suid_cfg_readable) {
                uid_t uid;
-               struct BB_suid_config *sct;
+               struct suid_config_t *sct;
                mode_t m;
 
                for (sct = suid_config; sct; sct = sct->m_next) {
@@ -516,6 +497,7 @@ static void check_suid(int applet_no)
                }
                goto check_need_suid;
  found:
+               /* Is this user allowed to run this applet? */
                m = sct->m_mode;
                if (sct->m_ugid.uid == ruid)
                        /* same uid */
@@ -523,29 +505,32 @@ static void check_suid(int applet_no)
                else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.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 (!(m & S_IXOTH))           /* is x bit not set ? */
-                       bb_error_msg_and_die("you have no permission to run this applet!");
+               /* We set effective AND saved ids. If saved-id is not set
+                * like we do below, seteuid(0) can still later succeed! */
 
-               /* _both_ sgid and group_exec have to be set for setegid */
-               if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
+               /* Are we directed to change gid
+                * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
+                */
+               if (sct->m_mode & S_ISGID)
                        rgid = sct->m_ugid.gid;
-               /* else (no setegid) we will set egid = rgid */
-
-               /* We set effective AND saved ids. If saved-id is not set
-                * like we do below, seteiud(0) can still later succeed! */
+               /* else: we will set egid = rgid, thus dropping sgid effect */
                if (setresgid(-1, rgid, rgid))
                        bb_perror_msg_and_die("setresgid");
 
-               /* do we have to set effective uid? */
+               /* Are we directed to change uid
+                * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
+                */
                uid = ruid;
                if (sct->m_mode & S_ISUID)
                        uid = sct->m_ugid.uid;
-               /* else (no seteuid) we will set euid = ruid */
-
+               /* else: we will set euid = ruid, thus dropping suid effect */
                if (setresuid(-1, uid, uid))
                        bb_perror_msg_and_die("setresuid");
-               return;
+
+               goto ret;
        }
 #   if !ENABLE_FEATURE_SUID_CONFIG_QUIET
        {
@@ -553,7 +538,7 @@ static void check_suid(int applet_no)
 
                if (!onetime) {
                        onetime = 1;
-                       fprintf(stderr, "Using fallback suid method\n");
+                       bb_error_msg("using fallback suid method");
                }
        }
 #   endif
@@ -568,6 +553,10 @@ static void check_suid(int applet_no)
                xsetgid(rgid);  /* drop all privileges */
                xsetuid(ruid);
        }
+#  if ENABLE_FEATURE_SUID_CONFIG
+ ret: ;
+       llist_free((llist_t*)suid_config, NULL);
+#  endif
 }
 # else
 #  define check_suid(x) ((void)0)
@@ -639,12 +628,15 @@ static int busybox_main(char **argv)
                full_write2_str(bb_banner); /* reuse const string */
                full_write2_str(" multi-call binary.\n"); /* reuse */
                full_write2_str(
-                       "Copyright (C) 1998-2009 Erik Andersen, Rob Landley, Denys Vlasenko\n"
-                       "and others. Licensed under GPLv2.\n"
-                       "See source distribution for full notice.\n"
+                       "BusyBox is copyrighted by many authors between 1998-2012.\n"
+                       "Licensed under GPLv2. See source distribution for detailed\n"
+                       "copyright notices.\n"
                        "\n"
-                       "Usage: busybox [function] [arguments]...\n"
-                       "   or: busybox --list[-full]\n"
+                       "Usage: busybox [function [arguments]...]\n"
+                       "   or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
+                       IF_FEATURE_INSTALLER(
+                       "   or: busybox --install [-s] [DIR]\n"
+                       )
                        "   or: function [arguments]...\n"
                        "\n"
                        "\tBusyBox is a multi-call binary that combines many common Unix\n"
@@ -684,7 +676,7 @@ static int busybox_main(char **argv)
                dup2(1, 2);
                while (*a) {
 # if ENABLE_FEATURE_INSTALLER
-                       if (argv[1][6]) /* --list-path? */
+                       if (argv[1][6]) /* --list-full? */
                                full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
 # endif
                        full_write2_str(a);
@@ -714,7 +706,7 @@ static int busybox_main(char **argv)
                 * -s: make symlinks
                 * DIR: directory to install links to
                 */
-               use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && argv++);
+               use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
                install_links(busybox, use_symbolic_links, argv[2]);
                return 0;
        }
@@ -756,8 +748,11 @@ void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
                /* Special case. POSIX says "test --help"
                 * should be no different from e.g. "test --foo".  */
 //TODO: just compare applet_no with APPLET_NO_test
-               if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
+               if (!ENABLE_TEST || strcmp(applet_name, "test") != 0) {
+                       /* If you want "foo --help" to return 0: */
+                       xfunc_error_retval = 0;
                        bb_show_usage();
+               }
        }
        if (ENABLE_FEATURE_SUID)
                check_suid(applet_no);
@@ -784,21 +779,18 @@ int main(int argc UNUSED_PARAM, char **argv)
 #endif
 {
        /* Tweak malloc for reduced memory consumption */
-#ifndef PAGE_SIZE
-# define PAGE_SIZE (4*1024) /* guess */
-#endif
 #ifdef M_TRIM_THRESHOLD
        /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
         * to keep before releasing to the OS
         * Default is way too big: 256k
         */
-       mallopt(M_TRIM_THRESHOLD, 2 * PAGE_SIZE);
+       mallopt(M_TRIM_THRESHOLD, 8 * 1024);
 #endif
 #ifdef M_MMAP_THRESHOLD
        /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
         * Default is too big: 256k
         */
-       mallopt(M_MMAP_THRESHOLD, 8 * PAGE_SIZE - 256);
+       mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
 #endif
 
 #if !BB_MMU