file_util: implement urlencode_path() helper

Introduce a helper function urlencode_path() which can be used to encode
problematic characters in package file names.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Tested-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/libopkg/file_util.c b/libopkg/file_util.c
index 1f89541420afdf6092c04e098df68e0271144a92..14ca02e30a727f0daa00a4d23353c9af1e1bd98a 100644 (file)
--- a/libopkg/file_util.c
+++ b/libopkg/file_util.c
@@ -346,3 +346,63 @@ int rm_r(const char *path)
 
        return ret;
 }
+
+static int urlencode_is_specialchar(char c)
+{
+       switch (c) {
+       case ':':
+       case '?':
+       case '#':
+       case '[':
+       case ']':
+       case '@':
+       case '!':
+       case '$':
+       case '&':
+       case '\'':
+       case '(':
+       case ')':
+       case '*':
+       case '+':
+       case ',':
+       case ';':
+       case '=':
+       case '%':
+               return 1;
+
+       default:
+               return 0;
+       }
+}
+
+char *urlencode_path(const char *filename)
+{
+       static const char bin2hex[16] = {
+               '0', '1', '2', '3',
+               '4', '5', '6', '7',
+               '8', '9', 'a', 'b',
+               'c', 'd', 'e', 'f'
+       };
+
+       size_t len = 0;
+       const char *in;
+       char *copy, *out;
+
+       for (in = filename; *in != 0; in++)
+               len += urlencode_is_specialchar(*in) ? 3 : 1;
+
+       copy = xcalloc(1, len + 1);
+
+       for (in = filename, out = copy; *in != 0; in++) {
+               if (urlencode_is_specialchar(*in)) {
+                       *out++ = '%';
+                       *out++ = bin2hex[*in / 16];
+                       *out++ = bin2hex[*in % 16];
+               }
+               else {
+                       *out++ = *in;
+               }
+       }
+
+       return copy;
+}

diff --git a/libopkg/file_util.h b/libopkg/file_util.h
index d8e676790aaa16c8917920fadacef4bdc781a56d..e078f41fd63143fc118077cb0798c33e34bc69f4 100644 (file)
--- a/libopkg/file_util.h
+++ b/libopkg/file_util.h
@@ -31,4 +31,6 @@ int rm_r(const char *path);
 char *checksum_bin2hex(const char *src, size_t len);
 char *checksum_hex2bin(const char *src, size_t *len);
 
+char *urlencode_path(const char *filename);
+
 #endif