main.c: Disallow invalid filenames or directory names

- Relative paths must not be used for filenames or directory names,
such as "..", "." or "dir/..".
- Paths with asterisks ('*') must not be allowed, to avoid confusion
with wildcard expressions.

1 files changed, 52 insertions, 13 deletions

diff --git a/main.c b/main.c
index 05e7d1b..2dee5f6 100644
--- a/main.c
+++ b/main.c
@@ -370,6 +370,21 @@ static bool path_isrel(const char *const path)
     return false;
 }
 
+static bool path_invalid(const char *const path)
+{
+    return path_isrel(path) || strchr(path, '*');
+}
+
+static bool filename_invalid(const char *const path)
+{
+    return path_invalid(path) || strchr(path, '/');
+}
+
+static bool dirname_invalid(const char *const path)
+{
+    return *path != '/' || path[strlen(path) - 1] != '/' || path_invalid(path);
+}
+
 static int getpublic(const struct http_payload *const p,
     struct http_response *const r, void *const user)
 {
@@ -385,7 +400,7 @@ static int getpublic(const struct http_payload *const p,
         fprintf(stderr, "%s: auth_dir failed\n", __func__);
         goto end;
     }
-    else if (path_isrel(p->resource))
+    else if (path_invalid(p->resource))
     {
         fprintf(stderr, "%s: illegal relative path %s\n",
             __func__, p->resource);
@@ -520,14 +535,14 @@ static int check_search_input(const struct http_payload *const p,
         *f = page_bad_request;
         goto end;
     }
-    else if (path_isrel(tdir) || *tdir != '/' || tdir[strlen(tdir) - 1] != '/')
+    else if (dirname_invalid(tdir))
     {
         fprintf(stderr, "%s: invalid directory %s\n", __func__, tdir);
         ret = 1;
         *f = page_bad_request;
         goto end;
     }
-    else if (strchr(tres, '/') || path_isrel(tres))
+    else if (filename_invalid(tres))
     {
         fprintf(stderr, "%s: invalid resource %s\n", __func__, tres);
         ret = 1;
@@ -741,7 +756,7 @@ static int share(const struct http_payload *const p,
 
     const char *const path = forms->value, *const username = p->cookie.field;
 
-    if (path_isrel(path))
+    if (path_invalid(path))
     {
         fprintf(stderr, "%s: invalid path %s\n", __func__, path);
         ret = page_bad_request(r);
@@ -870,7 +885,7 @@ static int getnode(const struct http_payload *const p,
     const char *const username = p->cookie.field,
         *const resource = p->resource + strlen("/user/");
 
-    if (path_isrel(resource))
+    if (path_invalid(resource))
     {
         fprintf(stderr, "%s: illegal relative path %s\n", __func__, resource);
         return page_forbidden(r);
@@ -1124,6 +1139,11 @@ static int upload_files(const struct http_payload *const p,
 
         return 0;
     }
+    else if (dirname_invalid(dir))
+    {
+        fprintf(stderr, "%s: invalid directory %s\n", __func__, dir);
+        return page_bad_request(r);
+    }
 
     for (size_t i = 0; i < po->n; i++)
     {
@@ -1218,13 +1238,13 @@ static int createdir(const struct http_payload *const p,
         ret = page_bad_request(r);
         goto end;
     }
-    else if (path_isrel(name) || strpbrk(name, "/*"))
+    else if (filename_invalid(name))
     {
         fprintf(stderr, "%s: invalid directory name %s\n", __func__, dir);
         ret = page_bad_request(r);
         goto end;
     }
-    else if (path_isrel(dir) || strchr(dir, '*'))
+    else if (dirname_invalid(dir))
     {
         fprintf(stderr, "%s: invalid name %s\n", __func__, name);
         ret = page_bad_request(r);
@@ -1318,6 +1338,15 @@ static int check_rm_input(const struct form *const forms, const size_t n,
         }
         else if (!strcmp(f->key, "path"))
         {
+            const char *const path = f->value;
+
+            if (path_isrel(path))
+            {
+                fprintf(stderr, "%s: invalid path %s\n", __func__, rm->dir);
+                *cb = page_bad_request;
+                return 1;
+            }
+
             const char **tmp = realloc(rm->items, (rm->n + 1) * sizeof *tmp);
 
             if (!tmp)
@@ -1327,7 +1356,7 @@ static int check_rm_input(const struct form *const forms, const size_t n,
                 return -1;
             }
 
-            tmp[rm->n++] = f->value;
+            tmp[rm->n++] = path;
             rm->items = tmp;
         }
     }
@@ -1338,7 +1367,7 @@ static int check_rm_input(const struct form *const forms, const size_t n,
         *cb = page_bad_request;
         return 1;
     }
-    else if (*rm->dir != '/' || path_isrel(rm->dir))
+    else if (dirname_invalid(rm->dir))
     {
         fprintf(stderr, "%s: invalid directory %s\n", __func__, rm->dir);
         *cb = page_bad_request;
@@ -1526,10 +1555,20 @@ static int do_rm(const struct form *const forms, const size_t n,
     {
         const struct form *const f = &forms[i];
 
-        if (!strcmp(f->key, "path") && rm_item(dir, f->value))
+        if (!strcmp(f->key, "path"))
         {
-            fprintf(stderr, "%s: rm_item failed\n", __func__);
-            return -1;
+            const char *const path = f->value;
+
+            if (path_isrel(path))
+            {
+                fprintf(stderr, "%s: invalid path %s\n", __func__, path);
+                return 1;
+            }
+            else if (rm_item(dir, f->value))
+            {
+                fprintf(stderr, "%s: rm_item failed\n", __func__);
+                return -1;
+            }
         }
     }
 
@@ -1580,7 +1619,7 @@ static int rm(const struct http_payload *const p,
         ret = f(r);
         goto end;
     }
-    else if (*dir != '/' || path_isrel(dir))
+    else if (dirname_invalid(dir))
     {
         fprintf(stderr, "%s: invalid directory %s\n", __func__, dir);
         ret = page_bad_request(r);