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 	TAILQ_INIT(&p->head);
49 }
50 
51 static void
52 gm_parse_selector(char *line, struct gm_selector *s)
53 {
54 	s->type = *line++;
55 	s->ds = line;
56 
57 	if ((line = strchr(line, '\t')) == NULL)
58 		return;
59         *line++ = '\0';
60 	s->selector = line;
61 
62 	if ((line = strchr(line, '\t')) == NULL)
63 		return;
64 	*line++ = '\0';
65 	s->addr = line;
66 
67 	if ((line = strchr(line, '\t')) == NULL)
68 		return;
69 	*line++ = '\0';
70 	s->port = line;
71 }
72 
73 static int
74 gm_parse(struct parser *p, const char *buf, size_t size)
75 {
76 	return parser_foreach_line(p, buf, size, gm_foreach_line);
77 }
78 
79 static inline int
80 emit_line(struct parser *p, enum line_type type, struct gm_selector *s)
81 {
82 	struct line *l;
83 	char buf[LINE_MAX], b[2] = {0};
84 
85 	if ((l = calloc(1, sizeof(*l))) == NULL)
86                 goto err;
87 
88 	if ((l->line = strdup(s->ds)) == NULL)
89 		goto err;
90 
91 	switch (l->type = type) {
92 	case LINE_LINK:
93 		if (s->type == 'h' && has_prefix(s->selector, "URL:")) {
94 			strlcpy(buf, s->selector+4, sizeof(buf));
95 		} else {
96 			strlcpy(buf, "gopher://", sizeof(buf));
97 			strlcat(buf, s->addr, sizeof(buf));
98 			strlcat(buf, ":", sizeof(buf));
99 			strlcat(buf, s->port, sizeof(buf));
100 			strlcat(buf, "/", sizeof(buf));
101 			b[0] = s->type;
102 			strlcat(buf, b, sizeof(buf));
103 			if (*s->selector != '/')
104 				strlcat(buf, "/", sizeof(buf));
105 			strlcat(buf, s->selector, sizeof(buf));
106 		}
107 
108 		if ((l->alt = strdup(buf)) == NULL)
109 			goto err;
110 		break;
111 
112 	default:
113 		break;
114 	}
115 
116 	TAILQ_INSERT_TAIL(&p->head, l, lines);
117 
118 	return 1;
119 
120 err:
121 	if (l != NULL) {
122 		free(l->line);
123 		free(l->alt);
124 		free(l);
125 	}
126 	return 0;
127 }
128 
129 static int
130 gm_foreach_line(struct parser *p, const char *line, size_t linelen)
131 {
132 	char buf[LINE_MAX] = {0};
133 	struct gm_selector s = {0};
134 
135 	memcpy(buf, line, MIN(sizeof(buf)-1, linelen));
136 	gm_parse_selector(buf, &s);
137 
138 	switch (s.type) {
139 	case '0':	/* text file */
140 	case '1':	/* gopher submenu */
141 	case '2':	/* CCSO nameserver */
142 	case '4':	/* binhex-encoded file */
143 	case '5':	/* DOS file */
144 	case '6':	/* uuencoded file */
145 	case '7':	/* full-text search */
146 	case '8':	/* telnet */
147 	case '9':	/* binary file */
148 	case '+':	/* mirror or alternate server */
149 	case 'g':	/* gif */
150 	case 'I':	/* image */
151 	case 'T':	/* telnet 3270 */
152 	case ':':	/* gopher+: bitmap image */
153 	case ';':	/* gopher+: movie file */
154 	case 'd':	/* non-canonical: doc */
155 	case 'h':	/* non-canonical: html file */
156 	case 's':	/* non-canonical: sound file */
157 		if (!emit_line(p, LINE_LINK, &s))
158 			return 0;
159 		break;
160 
161 		break;
162 
163 	case 'i':	/* non-canonical: message */
164 		if (!emit_line(p, LINE_TEXT, &s))
165 			return 0;
166 		break;
167 
168 	case '3':	/* error code */
169 		if (!emit_line(p, LINE_QUOTE, &s))
170 			return 0;
171 		break;
172 	}
173 
174 	return 1;
175 }
176 
177 static int
178 gm_free(struct parser *p)
179 {
180 	/* flush the buffer */
181 	if (p->len != 0)
182 		gm_foreach_line(p, p->buf, p->len);
183 
184 	free(p->buf);
185 
186 	return 1;
187 }