(trunk libT) #2096: add code magnet URL parser and unit tests

libtransmission/Makefile.am

@@ -27,6 +27,7 @@ libtransmission_a_SOURCES = \
     json.c \
     JSON_parser.c \
     list.c \
+    magnet.c \
     makemeta.c \
     metainfo.c \
     natpmp.c \
@@ -73,6 +74,7 @@ noinst_HEADERS = \
     json.h \
     JSON_parser.h \
     list.h \
+    magnet.h \
     makemeta.h \
     metainfo.h \
     natpmp.h \
@@ -108,6 +110,7 @@ TESTS = \
     bencode-test \
     clients-test \
     json-test \
+    magnet-test \
     peer-msgs-test \
     rpc-test \
     test-peer-id \
@@ -146,6 +149,10 @@ json_test_SOURCES = json-test.c
 json_test_LDADD = ${apps_ldadd}
 json_test_LDFLAGS = ${apps_ldflags}
 
+magnet_test_SOURCES = magnet-test.c
+magnet_test_LDADD = ${apps_ldadd}
+magnet_test_LDFLAGS = ${apps_ldflags}
+
 rpc_test_SOURCES = rpc-test.c
 rpc_test_LDADD = ${apps_ldadd}
 rpc_test_LDFLAGS = ${apps_ldflags}

libtransmission/magnet-test.c

@@ -0,0 +1,92 @@
+#include <stdio.h>
+#include <string.h>
+#include "transmission.h"
+#include "magnet.h"
+#include "utils.h"
+
+/* #define VERBOSE */
+#undef VERBOSE
+
+static int test = 0;
+
+#ifdef VERBOSE
+  #define check( A ) \
+    { \
+        ++test; \
+        if( A ){ \
+            fprintf( stderr, "PASS test #%d (%s, %d)\n", test, __FILE__, __LINE__ ); \
+        } else { \
+            fprintf( stderr, "FAIL test #%d (%s, %d)\n", test, __FILE__, __LINE__ ); \
+            return test; \
+        } \
+    }
+#else
+  #define check( A ) \
+    { \
+        ++test; \
+        if( !( A ) ){ \
+            fprintf( stderr, "FAIL test #%d (%s, %d)\n", test, __FILE__, __LINE__ ); \
+            return test; \
+        } \
+    }
+#endif
+
+static int
+test1( void )
+{
+    int i;
+    const char * uri;
+    tr_magnet_info * info;
+    const int dec[] = { 210, 53, 64, 16, 163, 202, 74, 222, 91, 116,
+                        39, 187, 9, 58, 98, 163, 137, 159, 243, 129 };
+
+    uri = "magnet:?xt=urn:btih:"
+          "d2354010a3ca4ade5b7427bb093a62a3899ff381"
+          "&dn=Display%20Name"
+          "&tr=http%3A%2F%2Ftracker.openbittorrent.com%2Fannounce"
+          "&tr=http%3A%2F%2Ftracker.opentracker.org%2Fannounce";
+    info = tr_magnetParse( uri );
+    check( info != NULL )
+    check( info->announceCount == 2 );
+    check( !strcmp( info->announceURLs[0], "http://tracker.openbittorrent.com/announce" ) )
+    check( !strcmp( info->announceURLs[1], "http://tracker.opentracker.org/announce" ) )
+    check( !strcmp( info->displayName, "Display Name" ) )
+    for( i=0; i<20; ++i )
+        check( info->hash[i] == dec[i] );
+    tr_magnetFree( info );
+    info = NULL;
+
+    /* same thing but in base32 encoding */
+    uri = "magnet:?xt=urn:btih:"
+          "2I2UAEFDZJFN4W3UE65QSOTCUOEZ744B"
+          "&dn=Display%20Name"
+          "&tr=http%3A%2F%2Ftracker.openbittorrent.com%2Fannounce"
+          "&tr=http%3A%2F%2Ftracker.opentracker.org%2Fannounce";
+    info = tr_magnetParse( uri );
+    check( info != NULL )
+    check( info->announceCount == 2 );
+    check( !strcmp( info->announceURLs[0], "http://tracker.openbittorrent.com/announce" ) )
+    check( !strcmp( info->announceURLs[1], "http://tracker.opentracker.org/announce" ) )
+    check( !strcmp( info->displayName, "Display Name" ) )
+    for( i=0; i<20; ++i )
+        check( info->hash[i] == dec[i] );
+    tr_magnetFree( info );
+    info = NULL;
+
+    return 0;
+}
+
+int
+main( void )
+{
+    int i;
+
+    if( ( i = test1( ) ) )
+        return i;
+
+#ifdef VERBOSE
+    fprintf( stderr, "magnet-test passed\n" );
+#endif
+    return 0;
+}
+

libtransmission/magnet.c

@@ -0,0 +1,184 @@
+/*
+ * This file Copyright (C) 2009 Charles Kerr <charles@transmissionbt.com>
+ *
+ * This file is licensed by the GPL version 2.  Works owned by the
+ * Transmission project are granted a special exemption to clause 2(b)
+ * so that the bulk of its code can remain under the MIT license.
+ * This exemption does not extend to derived works not owned by
+ * the Transmission project.
+ *
+ * $Id:$
+ */
+
+#include <assert.h>
+#include <ctype.h> /* tolower() */
+#include <string.h> /* strchr() */
+
+#include "transmission.h"
+#include "magnet.h"
+#include "utils.h"
+#include "web.h"
+
+/***
+****
+***/
+
+/* this base32 code converted from code by Robert Kaye and Gordon Mohr
+ * and is public domain.  see http://bitzi.com/publicdomain for more info */
+
+static const int base32Lookup[] =
+{
+    0xFF,0xFF,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F, // '0', '1', '2', '3', '4', '5', '6', '7'
+    0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, // '8', '9', ':', ';', '<', '=', '>', '?'
+    0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, // '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G'
+    0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, // 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O'
+    0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, // 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W'
+    0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF, // 'X', 'Y', 'Z', '[', '\', ']', '^', '_'
+    0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, // '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g'
+    0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, // 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o'
+    0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, // 'p', 'q', 'r', 's', 't', 'u', 'v', 'w'
+    0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF  // 'x', 'y', 'z', '{', '|', '}', '~', 'DEL'
+};
+
+static const int base32LookupLen = sizeof( base32Lookup ) / sizeof( base32Lookup[0] );
+
+static void
+base32_to_sha1( uint8_t * out, const char * in, const int inlen )
+{
+    const int outlen = 20;
+    int i, index, offset;
+
+    memset( out, 0, 20 );
+
+    assert( inlen == 32 );
+
+    for( i=0, index=0, offset=0; i<inlen; ++i )
+    {
+        int digit;
+        int lookup = in[i] - '0';
+ 
+        /* Skip chars outside the lookup table */
+        if( lookup<0 || lookup>=base32LookupLen )
+            continue;
+   
+        /* If this digit is not in the table, ignore it */
+        digit = base32Lookup[lookup];
+        if( digit == 0xFF )
+            continue;
+
+        if( index <= 3 ) {
+            index = (index + 5) % 8;
+            if( index == 0 ) {
+                out[offset] |= digit;
+                offset++;
+                if( offset >= outlen )
+                    break;
+            } else {
+                out[offset] |= digit << (8 - index);
+            }
+        } else {
+            index = (index + 5) % 8;
+            out[offset] |= (digit >> index);
+            offset++;
+   
+            if( offset >= outlen )
+                break;
+            out[offset] |= digit << (8 - index);
+       }
+   }
+}
+
+/***
+****
+***/
+
+#define MAX_TRACKERS 64
+
+tr_magnet_info *
+tr_magnetParse( const char * uri )
+{
+    tr_bool got_checksum = FALSE;
+    int announceCount = 0;
+    char * announceURLs[MAX_TRACKERS];
+    char * displayName = NULL;
+    uint8_t sha1[SHA_DIGEST_LENGTH];
+    tr_magnet_info * info = NULL;
+
+    if( ( uri != NULL ) && !memcmp( uri, "magnet:?", 8 ) )
+    {
+        const char * walk;
+
+        for( walk=uri+8; walk && *walk; )
+        {
+            const char * key = walk;
+            const char * delim = strchr( key, '=' );
+            const char * val = delim == NULL ? NULL : delim + 1;
+            const char * next = strchr( delim == NULL ? key : val, '&' );
+            int keylen, vallen;
+
+            if( delim != NULL )
+                keylen = delim - key;
+            else if( next != NULL )
+                keylen = next - key;
+            else
+                keylen = strlen( key );
+
+            if( val == NULL )
+                vallen = 0;
+            else if( next != NULL )
+                vallen = next - val;
+            else
+                vallen = strlen( val );
+
+            if( ( keylen==2 ) && !memcmp( key, "xt", 2 ) && !memcmp( val, "urn:btih:", 9 ) )
+            {
+                const char * hash = val + 9;
+                const int hashlen = vallen - 9;
+
+                if( hashlen == 40 ) {
+                    tr_hex_to_sha1( sha1, hash );
+                    got_checksum = TRUE;
+                }
+                else if( hashlen == 32 ) {
+                    base32_to_sha1( sha1, hash, hashlen );
+                    got_checksum = TRUE;
+                }
+            }
+
+            if( ( keylen==2 ) && !memcmp( key, "dn", 2 ) )
+                displayName = tr_http_unescape( val, vallen );
+
+            if( ( keylen==2 ) && !memcmp( key, "tr", 2 ) )
+                announceURLs[announceCount++] = tr_http_unescape( val, vallen );
+
+            walk = next != NULL ? next + 1 : NULL;
+        }
+    }
+
+    if( got_checksum )
+    {
+        info = tr_new0( tr_magnet_info, 1 );
+        info->displayName = displayName;
+        info->announceCount = announceCount;
+        info->announceURLs = tr_memdup( announceURLs, sizeof(char*) * announceCount );
+        memcpy( info->hash, sha1, sizeof(uint8_t) * SHA_DIGEST_LENGTH );
+    }
+
+    return info;
+}
+
+void
+tr_magnetFree( tr_magnet_info * info )
+{
+    if( info != NULL )
+    {
+        int i;
+
+        for( i=0; i<info->announceCount; ++i )
+            tr_free( info->announceURLs[i] );
+
+        tr_free( info->announceURLs );
+        tr_free( info->displayName );
+        tr_free( info );
+    }
+}

libtransmission/magnet.h

@@ -0,0 +1,31 @@
+/*
+ * This file Copyright (C) 2009 Charles Kerr <charles@transmissionbt.com>
+ *
+ * This file is licensed by the GPL version 2.  Works owned by the
+ * Transmission project are granted a special exemption to clause 2(b)
+ * so that the bulk of its code can remain under the MIT license.
+ * This exemption does not extend to derived works not owned by
+ * the Transmission project.
+ *
+ * $Id:$
+ */
+
+#ifndef TR_MAGNET_H
+#define TR_MAGNET_H 1
+
+#include "transmission.h"
+
+typedef struct
+{
+    uint8_t hash[20];
+    char * displayName;
+    char ** announceURLs;
+    int announceCount;
+}
+tr_magnet_info;
+
+tr_magnet_info * tr_magnetParse( const char * uri );
+
+void tr_magnetFree( tr_magnet_info * info );
+
+#endif

libtransmission/utils-test.c

@@ -8,6 +8,7 @@
 #include "utils.h"
 #include "crypto.h"
 
+/* #define VERBOSE */
 #undef VERBOSE
 #define NUM_LOOPS 1
 #define SPEED_TEST 0
@@ -281,6 +282,22 @@ test_memmem( void )
     return 0;
 }
 
+static int
+test_hex( void )
+{
+    char hex1[41];
+    char hex2[41];
+    uint8_t sha1[20];
+    /*uint8_t sha2[20];*/
+
+    memcpy( hex1, "fb5ef5507427b17e04b69cef31fa3379b456735a", 41 );
+    tr_hex_to_sha1( sha1, hex1 );
+    tr_sha1_to_hex( hex2, sha1 );
+    check( !strcmp( hex1, hex2 ) )
+
+    return 0;
+}
+
 int
 main( void )
 {
@@ -308,6 +325,8 @@ main( void )
     tr_free( in );
     tr_free( out );
 
+    if( ( i = test_hex( ) ) )
+        return i;
     if( ( i = test_lowerbound( ) ) )
         return i;
     if( ( i = test_strstrip( ) ) )

libtransmission/utils.c

@@ -902,21 +902,35 @@ tr_getRatio( double numerator,
 }
 
 void
-tr_sha1_to_hex( char *          out,
-                const uint8_t * sha1 )
+tr_sha1_to_hex( char * out, const uint8_t * sha1 )
 {
+    int i;
     static const char hex[] = "0123456789abcdef";
-    int               i;
 
-    for( i = 0; i < 20; i++ )
+    for( i=0; i<20; ++i )
     {
-        unsigned int val = *sha1++;
+        const unsigned int val = *sha1++;
         *out++ = hex[val >> 4];
         *out++ = hex[val & 0xf];
     }
+
     *out = '\0';
 }
 
+void
+tr_hex_to_sha1( uint8_t * out, const char * in )
+{
+    int i;
+    static const char hex[] = "0123456789abcdef";
+
+    for( i=0; i<20; ++i )
+    {
+        const int hi = strchr( hex, *in++ ) - hex;
+        const int lo = strchr( hex, *in++ ) - hex;
+        *out++ = (uint8_t)( (hi<<4) | lo );
+    }
+}
+
 /***
 ****
 ***/

libtransmission/utils.h

@@ -377,9 +377,12 @@ void        tr_set_compare( const void * a, size_t aCount,
                             tr_set_func in_both_cb,
                             void * userData );
 
-void tr_sha1_to_hex( char *          out,
+void tr_sha1_to_hex( char * out,
                      const uint8_t * sha1 ) TR_GNUC_NONNULL(1,2);
 
+void tr_hex_to_sha1( uint8_t * out,
+                     const char * hex ) TR_GNUC_NONNULL(1,2);
+
 
 tr_bool tr_httpIsValidURL( const char * url ) TR_GNUC_NONNULL(1);
 

libtransmission/web.c

@@ -684,3 +684,12 @@ tr_http_escape( struct evbuffer *out, const char *str, int len, int keep_slashes
         }
     }
 }
+
+char*
+tr_http_unescape( const char * str, int len )
+{
+    char * tmp = curl_unescape( str, len );
+    char * ret = tr_strdup( tmp );
+    curl_free( tmp );
+    return ret;
+}

libtransmission/web.h

@@ -40,4 +40,6 @@ struct evbuffer;
 
 void tr_http_escape( struct evbuffer *out, const char *str, int len, int noslashes );
 
+char* tr_http_unescape( const char * str, int len );
+
 #endif