/reddish/lib/sundown/src/autolink.c
C | 264 lines | 166 code | 62 blank | 36 comment | 91 complexity | 8f9891bc0353208ff16b978892cf16b0 MD5 | raw file
- /*
- * Copyright (c) 2011, Vicent Marti
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
- #include "buffer.h"
- #include <string.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <ctype.h>
- #if defined(_WIN32)
- #define strncasecmp _strnicmp
- #endif
- int
- sd_autolink_issafe(const uint8_t *link, size_t link_len)
- {
- static const char *valid_uris[] = {
- "/", "#", "http://", "https://", "ftp://", "mailto:", "irc://",
- };
- static const size_t valid_uris_count = 7;
- 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 &&
- isalnum(link[len]))
- return 1;
- }
- return 0;
- }
- static size_t
- autolink_delim(uint8_t *data, size_t link_end, size_t offset, size_t size)
- {
- uint8_t cclose, copen = 0;
- size_t i;
- for (i = 0; i < link_end; ++i)
- if (data[i] == '<') {
- link_end = i;
- break;
- }
- while (link_end > 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 && isalpha(data[new_end]))
- new_end--;
- if (new_end < link_end - 2 && data[new_end] == '&')
- link_end = new_end;
- else
- link_end--;
- }
- else break;
- }
- if (link_end == 0)
- return 0;
- cclose = data[link_end - 1];
- switch (cclose) {
- case '"': copen = '"'; break;
- case '\'': copen = '\''; break;
- case ')': copen = '('; break;
- case ']': copen = '['; break;
- case '}': copen = '{'; break;
- }
- if (copen != 0) {
- size_t closing = 0;
- size_t opening = 0;
- size_t i = 0;
- /* Try to close the final punctuation sign in this same line;
- * if we managed to close it outside of the URL, that means that it's
- * not part of the URL. If it closes inside the URL, that means it
- * is part of the URL.
- *
- * Examples:
- *
- * foo http://www.pokemon.com/Pikachu_(Electric) bar
- * => http://www.pokemon.com/Pikachu_(Electric)
- *
- * foo (http://www.pokemon.com/Pikachu_(Electric)) bar
- * => http://www.pokemon.com/Pikachu_(Electric)
- *
- * foo http://www.pokemon.com/Pikachu_(Electric)) bar
- * => http://www.pokemon.com/Pikachu_(Electric))
- *
- * (foo http://www.pokemon.com/Pikachu_(Electric)) bar
- * => foo 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)
- link_end--;
- }
- return link_end;
- }
- static size_t
- check_domain(uint8_t *data, size_t size)
- {
- size_t i, np = 0;
- if (!isalnum(data[0]))
- return 0;
- for (i = 1; i < size - 1; ++i) {
- if (data[i] == '.') np++;
- else if (!isalnum(data[i]) && data[i] != '-') break;
- }
- /* a valid domain needs to have at least a dot.
- * that's as far as we get */
- return np ? i : 0;
- }
- size_t
- sd_autolink__www(size_t *rewind_p, struct buf *link, uint8_t *data, size_t offset, size_t size)
- {
- size_t link_end;
- if (offset > 0 && !ispunct(data[-1]) && !isspace(data[-1]))
- return 0;
- if (size < 4 || memcmp(data, "www.", strlen("www.")) != 0)
- return 0;
- link_end = check_domain(data, size);
- if (link_end == 0)
- return 0;
- while (link_end < size && !isspace(data[link_end]))
- link_end++;
- link_end = autolink_delim(data, link_end, offset, size);
- if (link_end == 0)
- return 0;
- bufput(link, data, link_end);
- *rewind_p = 0;
- return (int)link_end;
- }
- size_t
- sd_autolink__email(size_t *rewind_p, struct buf *link, uint8_t *data, size_t offset, size_t size)
- {
- size_t link_end, rewind;
- int nb = 0, np = 0;
- for (rewind = 0; rewind < offset; ++rewind) {
- uint8_t c = data[-rewind - 1];
- if (isalnum(c))
- continue;
- if (strchr(".+-_", c) != NULL)
- continue;
- break;
- }
- if (rewind == 0)
- return 0;
- for (link_end = 0; link_end < size; ++link_end) {
- uint8_t c = data[link_end];
- if (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)
- return 0;
- link_end = autolink_delim(data, link_end, offset, size);
- if (link_end == 0)
- return 0;
- bufput(link, data - rewind, link_end + rewind);
- *rewind_p = rewind;
- return link_end;
- }
- size_t
- sd_autolink__url(size_t *rewind_p, struct buf *link, uint8_t *data, size_t offset, size_t size)
- {
- size_t link_end, rewind = 0, domain_len;
- if (size < 4 || data[1] != '/' || data[2] != '/')
- return 0;
- while (rewind < offset && 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);
- if (domain_len == 0)
- return 0;
- link_end += domain_len;
- while (link_end < size && !isspace(data[link_end]))
- link_end++;
- link_end = autolink_delim(data, link_end, offset, size);
- if (link_end == 0)
- return 0;
- bufput(link, data - rewind, link_end + rewind);
- *rewind_p = rewind;
- return link_end;
- }