diff options
Diffstat (limited to 'src/autolink.c')
| -rw-r--r-- | src/autolink.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/src/autolink.c b/src/autolink.c new file mode 100644 index 0000000..6f8d6ab --- /dev/null +++ b/src/autolink.c @@ -0,0 +1,297 @@ +/* + * 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 "autolink.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 size_t valid_uris_count = 5; + static const char *valid_uris[] = { + "/", "http://", "https://", "ftp://", "mailto:" + }; + + 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 max_rewind, 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, int allow_short) +{ + 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; + } + + 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; + } +} + +size_t +sd_autolink__www( + size_t *rewind_p, + struct buf *link, + uint8_t *data, + size_t max_rewind, + size_t size, + unsigned int flags) +{ + size_t link_end; + + if (max_rewind > 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, 0); + + if (link_end == 0) + return 0; + + while (link_end < size && !isspace(data[link_end])) + link_end++; + + link_end = autolink_delim(data, link_end, max_rewind, 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 max_rewind, + size_t size, + unsigned int flags) +{ + size_t link_end, rewind; + int nb = 0, np = 0; + + for (rewind = 0; rewind < max_rewind; ++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 || + !isalpha(data[link_end - 1])) + return 0; + + link_end = autolink_delim(data, link_end, max_rewind, 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 max_rewind, + size_t size, + unsigned int flags) +{ + size_t link_end, rewind = 0, domain_len; + + if (size < 4 || data[1] != '/' || data[2] != '/') + return 0; + + while (rewind < max_rewind && 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, + flags & SD_AUTOLINK_SHORT_DOMAINS); + + 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, max_rewind, size); + + if (link_end == 0) + return 0; + + bufput(link, data - rewind, link_end + rewind); + *rewind_p = rewind; + + return link_end; +} + |