#include "autolink.h"
#include <parser.h>
#include <string.h>
#include <utf8.h>
#if defined(_WIN32)
#define strncasecmp _strnicmp
#else
#include <strings.h>
#endif
static int is_valid_hostchar(const uint8_t *link, size_t link_len) {
int32_t ch;
int r = cmark_utf8proc_iterate(link, (bufsize_t)link_len, &ch);
if (r < 0)
return 0;
return !cmark_utf8proc_is_space(ch) && !cmark_utf8proc_is_punctuation(ch);
}
static int sd_autolink_issafe(const uint8_t *link, size_t link_len) {
static const size_t valid_uris_count = 3;
static const char *valid_uris[] = {"http://", "https://", "ftp://"};
size_t i;
for (i = 0; i < valid_uris_count; ++i) {
size_t len = strlen(valid_uris[i]);
if (link_len > len && strncasecmp((char *)link, valid_uris[i], len) == 0 &&
is_valid_hostchar(link + len, link_len - len))
return 1;
}
return 0;
}
static size_t autolink_delim(uint8_t *data, size_t link_end) {
uint8_t cclose, copen;
size_t i;
for (i = 0; i < link_end; ++i)
if (data[i] == '<') {
link_end = i;
break;
}
while (link_end > 0) {
cclose = data[link_end - 1];
switch (cclose) {
case ')':
copen = '(';
break;
default:
copen = 0;
}
if (strchr("?!.,:*_~'\"", data[link_end - 1]) != NULL)
link_end--;
else if (data[link_end - 1] == ';') {
size_t new_end = link_end - 2;
while (new_end > 0 && cmark_isalpha(data[new_end]))
new_end--;
if (new_end < link_end - 2 && data[new_end] == '&')
link_end = new_end;
else
link_end--;
} else if (copen != 0) {
size_t closing = 0;
size_t opening = 0;
i = 0;
/* Allow any number of matching brackets (as recognised in copen/cclose)
* at the end of the URL. If there is a greater number of closing
* brackets than opening ones, we remove one character from the end of
* the link.
*
* Examples (input text => output linked portion):
*
* http://www.pokemon.com/Pikachu_(Electric)
* => http://www.pokemon.com/Pikachu_(Electric)
*
* http://www.pokemon.com/Pikachu_((Electric)
* => http://www.pokemon.com/Pikachu_((Electric)
*
* http://www.pokemon.com/Pikachu_(Electric))
* => http://www.pokemon.com/Pikachu_(Electric)
*
* http://www.pokemon.com/Pikachu_((Electric))
* => http://www.pokemon.com/Pikachu_((Electric))
*/
while (i < link_end) {
if (data[i] == copen)
opening++;
else if (data[i] == cclose)
closing++;
i++;
}
if (closing <= opening)
break;
link_end--;
} else
break;
}
return link_end;
}
static size_t check_domain(uint8_t *data, size_t size, int allow_short) {
size_t i, np = 0, uscore1 = 0, uscore2 = 0;
for (i = 1; i < size - 1; i++) {
if (data[i] == '_')
uscore2++;
else if (data[i] == '.') {
uscore1 = uscore2;
uscore2 = 0;
np++;
} else if (!is_valid_hostchar(data + i, size - i) && data[i] != '-')
break;
}
if (uscore1 > 0 || uscore2 > 0)
return 0;
if (allow_short) {
/* We don't need a valid domain in the strict sense (with
* least one dot; so just make sure it's composed of valid
* domain characters and return the length of the the valid
* sequence. */
return i;
} else {
/* a valid domain needs to have at least a dot.
* that's as far as we get */
return np ? i : 0;
}
}
static cmark_node *www_match(cmark_parser *parser, cmark_node *parent,
cmark_inline_parser *inline_parser) {
cmark_chunk *chunk = cmark_inline_parser_get_chunk(inline_parser);
size_t max_rewind = cmark_inline_parser_get_offset(inline_parser);
uint8_t *data = chunk->data + max_rewind;
size_t size = chunk->len - max_rewind;
int start = cmark_inline_parser_get_column(inline_parser);
size_t link_end;
if (max_rewind > 0 && strchr("*_~(", data[-1]) == NULL &&
!cmark_isspace(data[-1]))
return 0;
if (size < 4 || memcmp(data, "www.", strlen("www.")) != 0)
return 0;
link_end = check_domain(data, size, 0);
if (link_end == 0)
return NULL;
while (link_end < size && !cmark_isspace(data[link_end]))
link_end++;
link_end = autolink_delim(data, link_end);
if (link_end == 0)
return NULL;
cmark_inline_parser_set_offset(inline_parser, (int)(max_rewind + link_end));
cmark_node *node = cmark_node_new_with_mem(CMARK_NODE_LINK, parser->mem);
cmark_strbuf buf;
cmark_strbuf_init(parser->mem, &buf, 10);
cmark_strbuf_puts(&buf, "http://");
cmark_strbuf_put(&buf, data, (bufsize_t)link_end);
node->as.link.url = cmark_chunk_buf_detach(&buf);
cmark_node *text = cmark_node_new_with_mem(CMARK_NODE_TEXT, parser->mem);
text->as.literal =
cmark_chunk_dup(chunk, (bufsize_t)max_rewind, (bufsize_t)link_end);
cmark_node_append_child(node, text);
node->start_line = text->start_line =
node->end_line = text->end_line =
cmark_inline_parser_get_line(inline_parser);
node->start_column = text->start_column = start - 1;
node->end_column = text->end_column = cmark_inline_parser_get_column(inline_parser) - 1;
return node;
}
static cmark_node *url_match(cmark_parser *parser, cmark_node *parent,
cmark_inline_parser *inline_parser) {
size_t link_end, domain_len;
int rewind = 0;
cmark_chunk *chunk = cmark_inline_parser_get_chunk(inline_parser);
int max_rewind = cmark_inline_parser_get_offset(inline_parser);
uint8_t *data = chunk->data + max_rewind;
size_t size = chunk->len - max_rewind;
if (size < 4 || data[1] != '/' || data[2] != '/')
return 0;
while (rewind < max_rewind && cmark_isalpha(data[-rewind - 1]))
rewind++;
if (!sd_autolink_issafe(data - rewind, size + rewind))
return 0;
link_end = strlen("://");
domain_len = check_domain(data + link_end, size - link_end, 1);
if (domain_len == 0)
return 0;
link_end += domain_len;
while (link_end < size && !cmark_isspace(data[link_end]))
link_end++;
link_end = autolink_delim(data, link_end);
if (link_end == 0)
return NULL;
cmark_inline_parser_set_offset(inline_parser, (int)(max_rewind + link_end));
cmark_node_unput(parent, rewind);
cmark_node *node = cmark_node_new_with_mem(CMARK_NODE_LINK, parser->mem);
cmark_chunk url = cmark_chunk_dup(chunk, max_rewind - rewind,
(bufsize_t)(link_end + rewind));
node->as.link.url = url;
cmark_node *text = cmark_node_new_with_mem(CMARK_NODE_TEXT, parser->mem);
text->as.literal = url;
cmark_node_append_child(node, text);
return node;
}
static cmark_node *match(cmark_syntax_extension *ext, cmark_parser *parser,
cmark_node *parent, unsigned char c,
cmark_inline_parser *inline_parser) {
if (cmark_inline_parser_in_bracket(inline_parser, false) ||
cmark_inline_parser_in_bracket(inline_parser, true))
return NULL;
if (c == ':')
return url_match(parser, parent, inline_parser);
if (c == 'w')
return www_match(parser, parent, inline_parser);
return NULL;
// note that we could end up re-consuming something already a
// part of an inline, because we don't track when the last
// inline was finished in inlines.c.
}
static void postprocess_text(cmark_parser *parser, cmark_node *text, int offset) {
size_t link_end;
uint8_t *data = text->as.literal.data,
*at;
size_t size = text->as.literal.len;
int rewind, max_rewind,
nb = 0, np = 0, ns = 0;
if (offset < 0 || (size_t)offset >= size)
return;
data += offset;
size -= offset;
at = (uint8_t *)memchr(data, '@', size);
if (!at)
return;
max_rewind = (int)(at - data);
data += max_rewind;
size -= max_rewind;
for (rewind = 0; rewind < max_rewind; ++rewind) {
uint8_t c = data[-rewind - 1];
if (cmark_isalnum(c))
continue;
if (strchr(".+-_", c) != NULL)
continue;
if (c == '/')
ns++;
break;
}
if (rewind == 0 || ns > 0) {
postprocess_text(parser, text, max_rewind + 1 + offset);
return;
}
for (link_end = 0; link_end < size; ++link_end) {
uint8_t c = data[link_end];
if (cmark_isalnum(c))
continue;
if (c == '@')
nb++;
else if (c == '.' && link_end < size - 1)
np++;
else if (c != '-' && c != '_')
break;
}
if (link_end < 2 || nb != 1 || np == 0 ||
(!cmark_isalpha(data[link_end - 1]) && data[link_end - 1] != '.')) {
postprocess_text(parser, text, max_rewind + 1 + offset);
return;
}
link_end = autolink_delim(data, link_end);
if (link_end == 0) {
postprocess_text(parser, text, max_rewind + 1 + offset);
return;
}
cmark_chunk_to_cstr(parser->mem, &text->as.literal);
cmark_node *link_node = cmark_node_new_with_mem(CMARK_NODE_LINK, parser->mem);
cmark_strbuf buf;
cmark_strbuf_init(parser->mem, &buf, 10);
cmark_strbuf_puts(&buf, "mailto:");
cmark_strbuf_put(&buf, data - rewind, (bufsize_t)(link_end + rewind));
link_node->as.link.url = cmark_chunk_buf_detach(&buf);
cmark_node *link_text = cmark_node_new_with_mem(CMARK_NODE_TEXT, parser->mem);
cmark_chunk email = cmark_chunk_dup(
&text->as.literal,
offset + max_rewind - rewind,
(bufsize_t)(link_end + rewind));
cmark_chunk_to_cstr(parser->mem, &email);
link_text->as.literal = email;
cmark_node_append_child(link_node, link_text);
cmark_node_insert_after(text, link_node);
cmark_node *post = cmark_node_new_with_mem(CMARK_NODE_TEXT, parser->mem);
post->as.literal = cmark_chunk_dup(&text->as.literal,
(bufsize_t)(offset + max_rewind + link_end),
(bufsize_t)(size - link_end));
cmark_chunk_to_cstr(parser->mem, &post->as.literal);
cmark_node_insert_after(link_node, post);
text->as.literal.len = offset + max_rewind - rewind;
text->as.literal.data[text->as.literal.len] = 0;
postprocess_text(parser, post, 0);
}
static cmark_node *postprocess(cmark_syntax_extension *ext, cmark_parser *parser, cmark_node *root) {
cmark_iter *iter;
cmark_event_type ev;
cmark_node *node;
bool in_link = false;
cmark_consolidate_text_nodes(root);
iter = cmark_iter_new(root);
while ((ev = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
node = cmark_iter_get_node(iter);
if (in_link) {
if (ev == CMARK_EVENT_EXIT && node->type == CMARK_NODE_LINK) {
in_link = false;
}
continue;
}
if (ev == CMARK_EVENT_ENTER && node->type == CMARK_NODE_LINK) {
in_link = true;
continue;
}
if (ev == CMARK_EVENT_ENTER && node->type == CMARK_NODE_TEXT) {
postprocess_text(parser, node, 0);
}
}
cmark_iter_free(iter);
return root;
}
cmark_syntax_extension *create_autolink_extension(void) {
cmark_syntax_extension *ext = cmark_syntax_extension_new("autolink");
cmark_llist *special_chars = NULL;
cmark_syntax_extension_set_match_inline_func(ext, match);
cmark_syntax_extension_set_postprocess_func(ext, postprocess);
cmark_mem *mem = cmark_get_default_mem_allocator();
special_chars = cmark_llist_append(mem, special_chars, (void *)':');
special_chars = cmark_llist_append(mem, special_chars, (void *)'w');
cmark_syntax_extension_set_special_inline_chars(ext, special_chars);
return ext;
}