1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "compat.h"
18 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 
23 #include "parser.h"
24 
25 struct gm_selector {
26 	char		 type;
27 	const char	*ds;
28 	const char	*selector;
29 	const char	*addr;
30 	const char	*port;
31 };
32 
33 static void	gm_parse_selector(char *, struct gm_selector *);
34 
35 static int	gm_parse(struct parser *, const char *, size_t);
36 static int	gm_foreach_line(struct parser *, const char *, size_t);
37 static int	gm_free(struct parser *);
38 
39 void
40 gophermap_initparser(struct parser *p)
41 {
42 	memset(p, 0, sizeof(*p));
43 
44 	p->name = "gophermap";
45 	p->parse = &gm_parse;
46 	p->free = &gm_free;
47 }
48 
49 static void
50 gm_parse_selector(char *line, struct gm_selector *s)
51 {
52 	s->type = *line++;
53 	s->ds = line;
54 
55 	if ((line = strchr(line, '\t')) == NULL)
56 		return;
57         *line++ = '\0';
58 	s->selector = line;
59 
60 	if ((line = strchr(line, '\t')) == NULL)
61 		return;
62 	*line++ = '\0';
63 	s->addr = line;
64 
65 	if ((line = strchr(line, '\t')) == NULL)
66 		return;
67 	*line++ = '\0';
68 	s->port = line;
69 }
70 
71 static int
72 gm_parse(struct parser *p, const char *buf, size_t size)
73 {
74 	return parser_foreach_line(p, buf, size, gm_foreach_line);
75 }
76 
77 static inline int
78 emit_line(struct parser *p, enum line_type type, struct gm_selector *s)
79 {
80 	struct line *l;
81 	char buf[LINE_MAX], b[2] = {0};
82 
83 	if ((l = calloc(1, sizeof(*l))) == NULL)
84                 goto err;
85 
86 	if ((l->line = strdup(s->ds)) == NULL)
87 		goto err;
88 
89 	switch (l->type = type) {
90 	case LINE_LINK:
91 		if (s->type == 'h' && has_prefix(s->selector, "URL:")) {
92 			strlcpy(buf, s->selector+4, sizeof(buf));
93 		} else {
94 			strlcpy(buf, "gopher://", sizeof(buf));
95 			strlcat(buf, s->addr, sizeof(buf));
96 			strlcat(buf, ":", sizeof(buf));
97 			strlcat(buf, s->port, sizeof(buf));
98 			strlcat(buf, "/", sizeof(buf));
99 			b[0] = s->type;
100 			strlcat(buf, b, sizeof(buf));
101 			if (*s->selector != '/')
102 				strlcat(buf, "/", sizeof(buf));
103 			strlcat(buf, s->selector, sizeof(buf));
104 		}
105 
106 		if ((l->alt = strdup(buf)) == NULL)
107 			goto err;
108 		break;
109 
110 	default:
111 		break;
112 	}
113 
114 	if (TAILQ_EMPTY(&p->head))
115 		TAILQ_INSERT_HEAD(&p->head, l, lines);
116 	else
117 		TAILQ_INSERT_TAIL(&p->head, l, lines);
118 
119 	return 1;
120 
121 err:
122 	if (l != NULL) {
123 		free(l->line);
124 		free(l->alt);
125 		free(l);
126 	}
127 	return 0;
128 }
129 
130 static int
131 gm_foreach_line(struct parser *p, const char *line, size_t linelen)
132 {
133 	char buf[LINE_MAX] = {0};
134 	struct gm_selector s = {0};
135 
136 	memcpy(buf, line, MIN(sizeof(buf)-1, linelen));
137 	gm_parse_selector(buf, &s);
138 
139 	switch (s.type) {
140 	case '0':	/* text file */
141 	case '1':	/* gopher submenu */
142 	case '2':	/* CCSO nameserver */
143 	case '4':	/* binhex-encoded file */
144 	case '5':	/* DOS file */
145 	case '6':	/* uuencoded file */
146 	case '7':	/* full-text search */
147 	case '8':	/* telnet */
148 	case '9':	/* binary file */
149 	case '+':	/* mirror or alternate server */
150 	case 'g':	/* gif */
151 	case 'I':	/* image */
152 	case 'T':	/* telnet 3270 */
153 	case ':':	/* gopher+: bitmap image */
154 	case ';':	/* gopher+: movie file */
155 	case 'd':	/* non-canonical: doc */
156 	case 'h':	/* non-canonical: html file */
157 	case 's':	/* non-canonical: sound file */
158 		if (!emit_line(p, LINE_LINK, &s))
159 			return 0;
160 		break;
161 
162 		break;
163 
164 	case 'i':	/* non-canonical: message */
165 		if (!emit_line(p, LINE_TEXT, &s))
166 			return 0;
167 		break;
168 
169 	case '3':	/* error code */
170 		if (!emit_line(p, LINE_QUOTE, &s))
171 			return 0;
172 		break;
173 	}
174 
175 	return 1;
176 }
177 
178 static int
179 gm_free(struct parser *p)
180 {
181 	/* flush the buffer */
182 	if (p->len != 0)
183 		gm_foreach_line(p, p->buf, p->len);
184 
185 	free(p->buf);
186 
187 	return 1;
188 }