teach find_root_device to deal with /dev/ subdirs

(by "Kirill K. Smirnov" <lich@math.spbu.ru>)

9 files changed, 71 insertions, 27 deletions

diff --git a/coreutils/ls.c b/coreutils/ls.c
index 7bbb19d6c..b9c07adf8 100644
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -504,11 +504,11 @@ static struct dnode **list_dir(const char *path)
 
                 /* are we going to list the file- it may be . or .. or a hidden file */
                 if (entry->d_name[0] == '.') {
-                        if ((entry->d_name[1] == 0 || (
-                                entry->d_name[1] == '.'
-                                && entry->d_name[2] == 0))
-                                        && !(all_fmt & DISP_DOT))
+                        if ((!entry->d_name[1] || (entry->d_name[1] == '.' && !entry->d_name[2]))
+                         && !(all_fmt & DISP_DOT)
+                        ) {
                                 continue;
+                        }
                         if (!(all_fmt & DISP_HIDDEN))
                                 continue;
                 }
diff --git a/coreutils/rm.c b/coreutils/rm.c
index 61e3e7010..e29073db8 100644
--- a/coreutils/rm.c
+++ b/coreutils/rm.c
@@ -40,7 +40,7 @@ int rm_main(int argc, char **argv)
                 do {
                         const char *base = bb_get_last_path_component(*argv);
 
-                        if ((base[0] == '.') && (!base[1] || ((base[1] == '.') && !base[2]))) {
+                        if (DOT_OR_DOTDOT(base)) {
                                 bb_error_msg("cannot remove '.' or '..'");
                         } else if (remove_file(*argv, flags) >= 0) {
                                 continue;
diff --git a/include/libbb.h b/include/libbb.h
index 29ee8daae..212b048de 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -405,6 +405,7 @@ extern char *xasprintf(const char *format, ...) __attribute__ ((format (printf,
 #define NOT_LONE_DASH(s) ((s)[0] != '-' || (s)[1])
 #define LONE_CHAR(s,c)     ((s)[0] == (c) && !(s)[1])
 #define NOT_LONE_CHAR(s,c) ((s)[0] != (c) || (s)[1])
+#define DOT_OR_DOTDOT(s) ((s)[0] == '.' && (!(s)[1] || ((s)[1] == '.' && !(s)[2])))
 
 /* dmalloc will redefine these to it's own implementation. It is safe
  * to have the prototypes here unconditionally.  */
diff --git a/libbb/concat_subpath_file.c b/libbb/concat_subpath_file.c
index 6bbe49ab5..1c0058889 100644
--- a/libbb/concat_subpath_file.c
+++ b/libbb/concat_subpath_file.c
@@ -17,7 +17,7 @@
 
 char *concat_subpath_file(const char *path, const char *f)
 {
-        if (f && *f == '.' && (!f[1] || (f[1] == '.' && !f[2])))
+        if (f && DOT_OR_DOTDOT(f))
                 return NULL;
         return concat_path_file(path, f);
 }
diff --git a/libbb/find_root_device.c b/libbb/find_root_device.c
index ea360eae5..7182102c7 100644
--- a/libbb/find_root_device.c
+++ b/libbb/find_root_device.c
@@ -9,26 +9,65 @@
 
 #include "libbb.h"
 
-char *find_block_device(const char *path)
+/* Find block device /dev/XXX which contains specified file
+ * We handle /dev/dir/dir/dir too, at a cost of ~80 more bytes code */
+
+/* Do not reallocate all this stuff on each recursion */
+enum { DEVNAME_MAX = 256 };
+struct arena {
+        struct stat st;
+        dev_t dev;
+        /* Was PATH_MAX, but we recurse _/dev_. We can assume
+         * people are not crazy enough to have mega-deep tree there */
+        char devpath[DEVNAME_MAX];
+};
+
+static char *find_block_device_in_dir(struct arena *ap)
 {
         DIR *dir;
         struct dirent *entry;
-        struct stat st;
-        dev_t dev;
-        char *retpath=NULL;
+        char *retpath = NULL;
+        int len, rem;
+
+        dir = opendir(ap->devpath);
+        if (!dir)
+                return NULL;
 
-        if (stat(path, &st) || !(dir = opendir("/dev")))
+        len = strlen(ap->devpath);
+        rem = DEVNAME_MAX-2 - len;
+        if (rem <= 0)
                 return NULL;
-        dev = (st.st_mode & S_IFMT) == S_IFBLK ? st.st_rdev : st.st_dev;
+        ap->devpath[len++] = '/';
+
         while ((entry = readdir(dir)) != NULL) {
-                char devpath[PATH_MAX];
-                sprintf(devpath,"/dev/%s", entry->d_name);
-                if (!stat(devpath, &st) && S_ISBLK(st.st_mode) && st.st_rdev == dev) {
-                        retpath = xstrdup(devpath);
+                safe_strncpy(ap->devpath + len, entry->d_name, rem);
+                if (stat(ap->devpath, &ap->st) != 0)
+                        continue;
+                if (S_ISBLK(ap->st.st_mode) && ap->st.st_rdev == ap->dev) {
+                        retpath = xstrdup(ap->devpath);
                         break;
                 }
+                if (S_ISDIR(ap->st.st_mode)) {
+                        /* Do not recurse for '.' and '..' */
+                        if (DOT_OR_DOTDOT(entry->d_name))
+                                continue;
+                        retpath = find_block_device_in_dir(ap);
+                        if (retpath)
+                                break;
+                }
         }
         closedir(dir);
 
         return retpath;
 }
+
+char *find_block_device(const char *path)
+{
+        struct arena a;
+
+        if (stat(path, &a.st) != 0)
+                return NULL;
+        a.dev = S_ISBLK(a.st.st_mode) ? a.st.st_rdev : a.st.st_dev;
+        strcpy(a.devpath, "/dev");
+        return find_block_device_in_dir(&a);
+}
diff --git a/libbb/simplify_path.c b/libbb/simplify_path.c
index 7e68e3911..29e371df6 100644
--- a/libbb/simplify_path.c
+++ b/libbb/simplify_path.c
@@ -26,13 +26,16 @@ char *bb_simplify_path(const char *path)
                 if (*p == '/') {
                         if (*s == '/') {        /* skip duplicate (or initial) slash */
                                 continue;
-                        } else if (*s == '.') {
-                                if (s[1] == '/' || s[1] == 0) { /* remove extra '.' */
+                        }
+                        if (*s == '.') {
+                                if (s[1] == '/' || !s[1]) {     /* remove extra '.' */
                                         continue;
-                                } else if ((s[1] == '.') && (s[2] == '/' || s[2] == 0)) {
+                                }
+                                if ((s[1] == '.') && (s[2] == '/' || !s[2])) {
                                         ++s;
                                         if (p > start) {
-                                                while (*--p != '/');    /* omit previous dir */
+                                                while (*--p != '/')     /* omit previous dir */
+                                                        continue;
                                         }
                                         continue;
                                 }
diff --git a/miscutils/devfsd.c b/miscutils/devfsd.c
index 0069b280e..d1a5163d2 100644
--- a/miscutils/devfsd.c
+++ b/miscutils/devfsd.c
@@ -1369,7 +1369,7 @@ static void dir_operation(int type, const char * dir_name, int var, unsigned lon
         while ( (de = readdir (dp) ) != NULL )
         {
 
-                if(de->d_name && *de->d_name == '.' && (!de->d_name[1] || (de->d_name[1] == '.' && !de->d_name[2])))
+                if(de->d_name && DOT_OR_DOTDOT(de->d_name))
                         continue;
                 snprintf (path, sizeof (path), "%s/%s", dir_name, de->d_name);
                 debug_msg_logger(LOG_ERR, "%s: %s", __FUNCTION__, path);
diff --git a/networking/httpd.c b/networking/httpd.c
index d80df937a..1f7c886de 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -1573,7 +1573,7 @@ static void handleIncoming(void)
                 }
 
                 /* algorithm stolen from libbb bb_simplify_path(),
-                         but don't strdup and reducing trailing slash and protect out root */
+                 * but don't strdup and reducing trailing slash and protect out root */
                 purl = test = url;
                 do {
                         if (*purl == '/') {
@@ -1583,18 +1583,18 @@ static void handleIncoming(void)
                                 }
                                 if (*test == '.') {
                                         /* skip extra '.' */
-                                        if (test[1] == '/' || test[1] == 0) {
+                                        if (test[1] == '/' || !test[1]) {
                                                 continue;
-                                        } else
+                                        }
                                         /* '..': be careful */
-                                        if (test[1] == '.' && (test[2] == '/' || test[2] == 0)) {
+                                        if (test[1] == '.' && (test[2] == '/' || !test[2])) {
                                                 ++test;
                                                 if (purl == url) {
                                                         /* protect out root */
                                                         goto BAD_REQUEST;
                                                 }
                                                 while (*--purl != '/') /* omit previous dir */;
-                                                continue;
+                                                        continue;
                                         }
                                 }
                         }
diff --git a/shell/ash.c b/shell/ash.c
index f8207a6cc..63f039df4 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2293,7 +2293,8 @@ updatepwd(const char *dir)
                                                 break;
                                 }
                                 break;
-                        } else if (p[1] == '\0')
+                        }
+                        if (p[1] == '\0')
                                 break;
                         /* fall through */
                 default: