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Diffstat (limited to 'src/css-url.c')
| -rw-r--r-- | src/css-url.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/src/css-url.c b/src/css-url.c new file mode 100644 index 0000000..c6e18bb --- /dev/null +++ b/src/css-url.c @@ -0,0 +1,235 @@ +/* Collect URLs from CSS source. + Copyright (C) 1998, 2000-2003, 2009-2011, 2014-2015, 2018-2022 Free + Software Foundation, Inc. + +This file is part of GNU Wget. + +GNU Wget is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3 of the License, or (at +your option) any later version. + +GNU Wget is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Wget. If not, see <http://www.gnu.org/licenses/>. + +Additional permission under GNU GPL version 3 section 7 + +If you modify this program, or any covered work, by linking or +combining it with the OpenSSL project's OpenSSL library (or a +modified version of that library), containing parts covered by the +terms of the OpenSSL or SSLeay licenses, the Free Software Foundation +grants you additional permission to convey the resulting work. +Corresponding Source for a non-source form of such a combination +shall include the source code for the parts of OpenSSL used as well +as that of the covered work. */ + +/* + Note that this is not an actual CSS parser, but just a lexical + scanner with a tiny bit more smarts bolted on top. A full parser + is somewhat overkill for this job. The only things we're interested + in are @import rules and url() tokens, so it's easy enough to + grab those without truly understanding the input. The only downside + to this is that we might be coerced into downloading files that + a browser would ignore. That might merit some more investigation. + */ + +#include "wget.h" + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <ctype.h> +#include <errno.h> + +#include "utils.h" +#include "convert.h" +#include "html-url.h" +#include "css-tokens.h" +#include "css-url.h" +#include "xstrndup.h" + +/* from lex.yy.c */ +extern char *yytext; +extern int yyleng; +typedef struct yy_buffer_state *YY_BUFFER_STATE; +extern YY_BUFFER_STATE yy_scan_bytes (const char *bytes,int len ); +extern void yy_delete_buffer (YY_BUFFER_STATE b); +extern int yylex (void); +extern void yylex_destroy(void); + +/* + Given a detected URI token, get only the URI specified within. + Also adjust the starting position and length of the string. + + A URI can be specified with or without quotes, and the quotes + can be single or double quotes. In addition there can be + whitespace after the opening parenthesis and before the closing + parenthesis. +*/ +static char * +get_uri_string (const char *at, int *pos, int *length) +{ + if (*length < 4) + return NULL; + + if (0 != strncasecmp (at + *pos, "url(", 4)) + return NULL; + + *pos += 4; + *length -= 5; /* url() */ + + /* skip leading space */ + while (*length > 0 && isspace (at[*pos])) + { + (*pos)++; + if (--(*length) == 0) + return NULL; + } + + /* skip trailing space */ + while (*length > 0 && isspace (at[*pos + *length - 1])) + { + (*length)--; + } + + /* trim off quotes */ + if (*length >= 2 && (at[*pos] == '\'' || at[*pos] == '"')) + { + (*pos)++; + *length -= 2; + } + + if (*length <= 0) + return NULL; + + return xstrndup (at + *pos, *length); +} + +void +get_urls_css (struct map_context *ctx, int offset, int buf_length) +{ + int token; + /*char tmp[2048];*/ + int buffer_pos = 0; + int pos, length; + char *uri; + YY_BUFFER_STATE b; + + /* tell flex to scan from this buffer */ + b = yy_scan_bytes (ctx->text + offset, buf_length); + + while((token = yylex()) != CSSEOF) + { + /*DEBUGP (("%s ", token_names[token]));*/ + /* @import "foo.css" + or @import url(foo.css) + */ + if(token == IMPORT_SYM) + { + do { + buffer_pos += yyleng; + } while((token = yylex()) == S); + + /*DEBUGP (("%s ", token_names[token]));*/ + + if (token == STRING || token == URI) + { + /*DEBUGP (("Got URI "));*/ + pos = buffer_pos + offset; + length = yyleng; + + if (token == URI) + { + uri = get_uri_string (ctx->text, &pos, &length); + } + else if (length >= 2) + { + /* cut out quote characters */ + pos++; + length -= 2; + uri = xmalloc (length + 1); + memcpy (uri, yytext + 1, length); + uri[length] = '\0'; + } + else + uri = NULL; + + if (uri) + { + struct urlpos *up = append_url (uri, pos, length, ctx); + DEBUGP (("Found @import: [%s] at %d [%s]\n", yytext, buffer_pos, uri)); + + if (up) + { + up->link_inline_p = 1; + up->link_css_p = 1; + up->link_expect_css = 1; + } + + xfree(uri); + } + } + } + /* background-image: url(foo.png) + note that we don't care what + property this is actually on. + */ + else if(token == URI) + { + pos = buffer_pos + offset; + length = yyleng; + uri = get_uri_string (ctx->text, &pos, &length); + + if (uri) + { + struct urlpos *up = append_url (uri, pos, length, ctx); + DEBUGP (("Found URI: [%s] at %d [%s]\n", yytext, buffer_pos, uri)); + if (up) + { + up->link_inline_p = 1; + up->link_css_p = 1; + } + + xfree (uri); + } + } + buffer_pos += yyleng; + } + + yy_delete_buffer(b); + yylex_destroy(); + + DEBUGP (("\n")); +} + +struct urlpos * +get_urls_css_file (const char *file, const char *url) +{ + struct file_memory *fm; + struct map_context ctx; + + /* Load the file. */ + fm = wget_read_file (file); + if (!fm) + { + logprintf (LOG_NOTQUIET, "%s: %s\n", file, strerror (errno)); + return NULL; + } + DEBUGP (("Loaded %s (size %s).\n", file, number_to_static_string (fm->length))); + + ctx.text = fm->content; + ctx.head = NULL; + ctx.base = NULL; + ctx.parent_base = url ? url : opt.base_href; + ctx.document_file = file; + ctx.nofollow = 0; + + get_urls_css (&ctx, 0, fm->length); + wget_read_file_free (fm); + return ctx.head; +} |