1 /* $OpenBSD: forward.c,v 1.40 2021/06/14 17:58:15 eric Exp $ */
2
3 /*
4 * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/stat.h>
20
21 #include <stdlib.h>
22 #include <util.h>
23 #include <unistd.h>
24
25 #include "smtpd.h"
26 #include "log.h"
27
28 #define MAX_FORWARD_SIZE (4 * 1024)
29 #define MAX_EXPAND_NODES (100)
30
31 int
forwards_get(int fd,struct expand * expand)32 forwards_get(int fd, struct expand *expand)
33 {
34 FILE *fp = NULL;
35 char *line = NULL;
36 size_t len;
37 size_t lineno;
38 size_t save;
39 int ret;
40 struct stat sb;
41
42 ret = -1;
43 if (fstat(fd, &sb) == -1)
44 goto end;
45
46 /* if it's empty just pretend that no expansion took place */
47 if (sb.st_size == 0) {
48 log_info("info: forward file is empty");
49 ret = 0;
50 goto end;
51 }
52
53 /* over MAX_FORWARD_SIZE, temporarily fail */
54 if (sb.st_size >= MAX_FORWARD_SIZE) {
55 log_info("info: forward file exceeds max size");
56 goto end;
57 }
58
59 if ((fp = fdopen(fd, "r")) == NULL) {
60 log_warn("warn: fdopen failure in forwards_get()");
61 goto end;
62 }
63
64 lineno = 0;
65 save = expand->nb_nodes;
66 while ((line = fparseln(fp, &len, &lineno, NULL, 0)) != NULL) {
67 if (!expand_line(expand, line, 0)) {
68 log_info("info: parse error in forward file");
69 goto end;
70 }
71 if (expand->nb_nodes > MAX_EXPAND_NODES) {
72 log_info("info: forward file expanded too many nodes");
73 goto end;
74 }
75 free(line);
76 }
77
78 ret = expand->nb_nodes > save ? 1 : 0;
79
80 end:
81 free(line);
82 if (fp)
83 fclose(fp);
84 else
85 close(fd);
86 return ret;
87 }
88