summary refs log tree commit diff
path: root/www/text.causal.agency/igp.c
blob: b9e7241baf1dffa15a104d68f0b972d143f1bb72 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/* Copyright (C) 2021  June McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sysexits.h>
#include <time.h>
#include <unistd.h>

#ifdef __FreeBSD__
#include <sys/capsicum.h>
#endif

static int compar(const void *_a, const void *_b) {
	const struct dirent *a = _a;
	const struct dirent *b = _b;
	if (a->d_type != b->d_type) {
		return (a->d_type > b->d_type) - (a->d_type < b->d_type);
	}
	return strcmp(a->d_name, b->d_name);
}

int main(int argc, char *argv[]) {
	int error;
	const char *host = NULL;
	const char *port = "70";
	for (int opt; 0 < (opt = getopt(argc, argv, "h:p:"));) {
		switch (opt) {
			break; case 'h': host = optarg;
			break; case 'p': port = optarg;
			break; default:  return EX_USAGE;
		}
	}
	if (optind == argc) return EX_USAGE;
	if (!host) {
		static char buf[256];
		error = gethostname(buf, sizeof(buf));
		if (error) abort();
		host = buf;
	}

	const char *path = argv[optind];
	int root = open(path, O_RDONLY | O_DIRECTORY);
	if (root < 0) err(EX_NOINPUT, "/");

#ifdef __FreeBSD__
	cap_rights_t cap;
	error = cap_enter()
		|| cap_rights_limit(STDIN_FILENO, cap_rights_init(&cap, CAP_READ))
		|| cap_rights_limit(STDOUT_FILENO, cap_rights_init(&cap, CAP_WRITE))
		|| cap_rights_limit(
			root, cap_rights_init(&cap, CAP_PREAD, CAP_FSTATAT, CAP_FSTATFS)
		);
	if (error) abort();
#else
#warning "This is completely insecure without capsicum(4)!"
#endif

	char buf[1024];
	if (!fgets(buf, sizeof(buf), stdin)) return EX_PROTOCOL;
	char *ptr = buf;
	char *sel = strsep(&ptr, "\t\r\n");
	if (sel[0] == '/') sel++;

	int fd = (sel[0] ? openat(root, sel, O_RDONLY) : root);
	if (fd < 0) err(EX_NOINPUT, "%s", sel);

	struct stat stat;
	error = fstat(fd, &stat);
	if (error) err(EX_IOERR, "%s", sel);
	if (!(stat.st_mode & (S_IFREG | S_IFDIR))) {
		errx(EX_NOINPUT, "%s: Not a file or directory", sel);
	}

	if (stat.st_mode & S_IFREG) {
#ifdef __FreeBSD__
		error = sendfile(fd, STDOUT_FILENO, 0, 0, NULL, NULL, 0);
		if (!error) return EX_OK;
#endif
		char buf[4096];
		for (ssize_t len; 0 < (len = read(fd, buf, sizeof(buf)));) {
			fwrite(buf, len, 1, stdout);
		}
		return EX_OK;
	}

	DIR *dir = fdopendir(fd);
	if (!dir) err(EX_IOERR, "%s", sel);

	size_t len = 0;
	size_t width = 0;
	static struct dirent ents[4096];
	for (struct dirent *ent; len < 4096 && (ent = readdir(dir));) {
		if (ent->d_name[0] == '.') continue;
		if (ent->d_type != DT_REG && ent->d_type != DT_DIR) continue;
		if (ent->d_namlen > width) width = ent->d_namlen;
		ents[len++] = *ent;
	}

	qsort(ents, len, sizeof(ents[0]), compar);
	for (size_t i = 0; i < len; ++i) {
		char mtime[26] = "";
		if (ents[i].d_type == DT_REG) {
			error = fstatat(fd, ents[i].d_name, &stat, 0);
			if (error) err(EX_IOERR, "%s/%s", sel, ents[i].d_name);
			ctime_r(&stat.st_mtime, mtime);
			mtime[24] = '\0';
		}
		printf(
			"%c%-*s  %s\t%s%s%s\t%s\t%s\r\n",
			(ents[i].d_type == DT_DIR ? '1' : '0'),
			(int)width, ents[i].d_name, mtime,
			sel, (sel[0] ? "/" : ""), ents[i].d_name, host, port
		);
	}

	printf("i-- \t\t%s\t%s\r\n", host, port);
	printf("0Served by IGP (AGPLv3)\tigp.c\ttext.causal.agency\t70\r\n");
	printf(".\r\n");
}