1/* Collect URLs from CSS source. 2 Copyright (C) 1998, 2000, 2001, 2002, 2003, 2009 Free Software 3 Foundation, Inc. 4 5This file is part of GNU Wget. 6 7GNU Wget is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 3 of the License, or (at 10your option) any later version. 11 12GNU Wget is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17You should have received a copy of the GNU General Public License 18along with Wget. If not, see <http://www.gnu.org/licenses/>. 19 20Additional permission under GNU GPL version 3 section 7 21 22If you modify this program, or any covered work, by linking or 23combining it with the OpenSSL project's OpenSSL library (or a 24modified version of that library), containing parts covered by the 25terms of the OpenSSL or SSLeay licenses, the Free Software Foundation 26grants you additional permission to convey the resulting work. 27Corresponding Source for a non-source form of such a combination 28shall include the source code for the parts of OpenSSL used as well 29as that of the covered work. */ 30 31/* 32 Note that this is not an actual CSS parser, but just a lexical 33 scanner with a tiny bit more smarts bolted on top. A full parser 34 is somewhat overkill for this job. The only things we're interested 35 in are @import rules and url() tokens, so it's easy enough to 36 grab those without truly understanding the input. The only downside 37 to this is that we might be coerced into downloading files that 38 a browser would ignore. That might merit some more investigation. 39 */ 40 41#include <wget.h> 42 43#include <stdio.h> 44#ifdef HAVE_STRING_H 45# include <string.h> 46#else 47# include <strings.h> 48#endif 49#include <stdlib.h> 50#include <ctype.h> 51#include <errno.h> 52 53#include "wget.h" 54#include "utils.h" 55#include "convert.h" 56#include "html-url.h" 57#include "css-tokens.h" 58 59/* from lex.yy.c */ 60extern char *yytext; 61extern int yyleng; 62typedef struct yy_buffer_state *YY_BUFFER_STATE; 63extern YY_BUFFER_STATE yy_scan_bytes (const char *bytes,int len ); 64extern int yylex (void); 65 66#if 1 67const char *token_names[] = { 68 "CSSEOF", 69 "S", 70 "CDO", 71 "CDC", 72 "INCLUDES", 73 "DASHMATCH", 74 "LBRACE", 75 "PLUS", 76 "GREATER", 77 "COMMA", 78 "STRING", 79 "INVALID", 80 "IDENT", 81 "HASH", 82 "IMPORT_SYM", 83 "PAGE_SYM", 84 "MEDIA_SYM", 85 "CHARSET_SYM", 86 "IMPORTANT_SYM", 87 "EMS", 88 "EXS", 89 "LENGTH", 90 "ANGLE", 91 "TIME", 92 "FREQ", 93 "DIMENSION", 94 "PERCENTAGE", 95 "NUMBER", 96 "URI", 97 "FUNCTION" 98}; 99#endif 100 101/* 102 Given a detected URI token, get only the URI specified within. 103 Also adjust the starting position and length of the string. 104 105 A URI can be specified with or without quotes, and the quotes 106 can be single or double quotes. In addition there can be 107 whitespace after the opening parenthesis and before the closing 108 parenthesis. 109*/ 110char * 111get_uri_string (const char *at, int *pos, int *length) 112{ 113 char *uri; 114 /*char buf[1024]; 115 strncpy(buf,at + *pos, *length); 116 buf[*length] = '\0'; 117 DEBUGP (("get_uri_string: \"%s\"\n", buf));*/ 118 119 if (0 != strncasecmp (at + *pos, "url(", 4)) 120 return NULL; 121 122 *pos += 4; 123 *length -= 5; /* url() */ 124 /* skip leading space */ 125 while (isspace (at[*pos])) 126 { 127 (*pos)++; 128 (*length)--; 129 } 130 /* skip trailing space */ 131 while (isspace (at[*pos + *length - 1])) 132 { 133 (*length)--; 134 } 135 /* trim off quotes */ 136 if (at[*pos] == '\'' || at[*pos] == '"') 137 { 138 (*pos)++; 139 *length -= 2; 140 } 141 142 uri = xmalloc (*length + 1); 143 if (uri) 144 { 145 strncpy (uri, at + *pos, *length); 146 uri[*length] = '\0'; 147 } 148 149 return uri; 150} 151 152void 153get_urls_css (struct map_context *ctx, int offset, int buf_length) 154{ 155 int token; 156 /*char tmp[2048];*/ 157 int buffer_pos = 0; 158 int pos, length; 159 char *uri; 160 161 /* 162 strncpy(tmp,ctx->text + offset, buf_length); 163 tmp[buf_length] = '\0'; 164 DEBUGP (("get_urls_css: \"%s\"\n", tmp)); 165 */ 166 167 /* tell flex to scan from this buffer */ 168 yy_scan_bytes (ctx->text + offset, buf_length); 169 170 while((token = yylex()) != CSSEOF) 171 { 172 /*DEBUGP (("%s ", token_names[token]));*/ 173 /* @import "foo.css" 174 or @import url(foo.css) 175 */ 176 if(token == IMPORT_SYM) 177 { 178 do { 179 buffer_pos += yyleng; 180 } while((token = yylex()) == S); 181 182 /*DEBUGP (("%s ", token_names[token]));*/ 183 184 if (token == STRING || token == URI) 185 { 186 /*DEBUGP (("Got URI "));*/ 187 pos = buffer_pos + offset; 188 length = yyleng; 189 190 if (token == URI) 191 { 192 uri = get_uri_string (ctx->text, &pos, &length); 193 } 194 else 195 { 196 /* cut out quote characters */ 197 pos++; 198 length -= 2; 199 uri = xmalloc (length + 1); 200 strncpy (uri, yytext + 1, length); 201 uri[length] = '\0'; 202 } 203 204 if (uri) 205 { 206 struct urlpos *up = append_url (uri, pos, length, ctx); 207 DEBUGP (("Found @import: [%s] at %d [%s]\n", yytext, buffer_pos, uri)); 208 209 if (up) 210 { 211 up->link_inline_p = 1; 212 up->link_css_p = 1; 213 up->link_expect_css = 1; 214 } 215 216 xfree(uri); 217 } 218 } 219 } 220 /* background-image: url(foo.png) 221 note that we don't care what 222 property this is actually on. 223 */ 224 else if(token == URI) 225 { 226 pos = buffer_pos + offset; 227 length = yyleng; 228 uri = get_uri_string (ctx->text, &pos, &length); 229 230 if (uri) 231 { 232 struct urlpos *up = append_url (uri, pos, length, ctx); 233 DEBUGP (("Found URI: [%s] at %d [%s]\n", yytext, buffer_pos, uri)); 234 if (up) 235 { 236 up->link_inline_p = 1; 237 up->link_css_p = 1; 238 } 239 240 xfree (uri); 241 } 242 } 243 buffer_pos += yyleng; 244 } 245 DEBUGP (("\n")); 246} 247 248struct urlpos * 249get_urls_css_file (const char *file, const char *url) 250{ 251 struct file_memory *fm; 252 struct map_context ctx; 253 254 /* Load the file. */ 255 fm = read_file (file); 256 if (!fm) 257 { 258 logprintf (LOG_NOTQUIET, "%s: %s\n", file, strerror (errno)); 259 return NULL; 260 } 261 DEBUGP (("Loaded %s (size %s).\n", file, number_to_static_string (fm->length))); 262 263 ctx.text = fm->content; 264 ctx.head = ctx.tail = NULL; 265 ctx.base = NULL; 266 ctx.parent_base = url ? url : opt.base_href; 267 ctx.document_file = file; 268 ctx.nofollow = 0; 269 270 get_urls_css (&ctx, 0, fm->length); 271 read_file_free (fm); 272 return ctx.head; 273} 274