1 /* $OpenBSD: mda_unpriv.c,v 1.9 2024/03/15 21:52:20 op Exp $ */
2
3 /*
4 * Copyright (c) 2018 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 <err.h>
20 #include <paths.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include "smtpd.h"
25
26 void
mda_unpriv(struct dispatcher * dsp,struct deliver * deliver,const char * pw_name,const char * pw_dir)27 mda_unpriv(struct dispatcher *dsp, struct deliver *deliver,
28 const char *pw_name, const char *pw_dir)
29 {
30 int idx;
31 char *mda_environ[12];
32 char mda_exec[LINE_MAX];
33 char mda_wrapper[LINE_MAX];
34 const char *mda_command;
35 const char *mda_command_wrap;
36
37 if (deliver->mda_exec[0])
38 mda_command = deliver->mda_exec;
39 else
40 mda_command = dsp->u.local.command;
41
42 if (strlcpy(mda_exec, mda_command, sizeof (mda_exec))
43 >= sizeof (mda_exec))
44 errx(1, "mda command line too long");
45
46 if (mda_expand_format(mda_exec, sizeof mda_exec, deliver,
47 &deliver->userinfo, NULL) == -1)
48 errx(1, "mda command line could not be expanded");
49
50 mda_command = mda_exec;
51
52 /* setup environment similar to other MTA */
53 idx = 0;
54 xasprintf(&mda_environ[idx++], "PATH=%s", _PATH_DEFPATH);
55 xasprintf(&mda_environ[idx++], "DOMAIN=%s", deliver->rcpt.domain);
56 xasprintf(&mda_environ[idx++], "HOME=%s", pw_dir);
57 xasprintf(&mda_environ[idx++], "ORIGINAL_RECIPIENT=%s@%s", deliver->rcpt.user, deliver->rcpt.domain);
58 xasprintf(&mda_environ[idx++], "RECIPIENT=%s@%s", deliver->dest.user, deliver->dest.domain);
59 xasprintf(&mda_environ[idx++], "SHELL=/bin/sh");
60 xasprintf(&mda_environ[idx++], "LOCAL=%s", deliver->rcpt.user);
61 xasprintf(&mda_environ[idx++], "LOGNAME=%s", deliver->userinfo.username);
62 xasprintf(&mda_environ[idx++], "USER=%s", deliver->userinfo.username);
63
64 if (deliver->sender.user[0])
65 xasprintf(&mda_environ[idx++], "SENDER=%s@%s",
66 deliver->sender.user, deliver->sender.domain);
67 else
68 xasprintf(&mda_environ[idx++], "SENDER=");
69
70 if (deliver->mda_subaddress[0])
71 xasprintf(&mda_environ[idx++], "EXTENSION=%s", deliver->mda_subaddress);
72
73 mda_environ[idx++] = (char *)NULL;
74
75 if (dsp->u.local.mda_wrapper) {
76 mda_command_wrap = dict_get(env->sc_mda_wrappers,
77 dsp->u.local.mda_wrapper);
78 if (mda_command_wrap == NULL)
79 errx(1, "could not find wrapper %s",
80 dsp->u.local.mda_wrapper);
81
82 if (strlcpy(mda_wrapper, mda_command_wrap, sizeof (mda_wrapper))
83 >= sizeof (mda_wrapper))
84 errx(1, "mda command line too long");
85
86 if (mda_expand_format(mda_wrapper, sizeof mda_wrapper, deliver,
87 &deliver->userinfo, mda_command) == -1)
88 errx(1, "mda command line could not be expanded");
89 mda_command = mda_wrapper;
90 }
91 execle("/bin/sh", "/bin/sh", "-c", mda_command, (char *)NULL,
92 mda_environ);
93
94 perror("execle");
95 _exit(1);
96 }
97
98