Commit | Line | Data |
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7cbe3601 | 1 | /* $OpenBSD: src/sbin/dhclient/privsep.c,v 1.16 2011/04/04 11:14:52 krw Exp $ */ |
846204b6 HT |
2 | |
3 | /* | |
4 | * Copyright (c) 2004 Henning Brauer <henning@openbsd.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 MIND, USE, DATA OR PROFITS, WHETHER IN | |
15 | * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT | |
16 | * OF OR IN CONNECTION WITH THE USE, ABUSE OR PERFORMANCE OF THIS SOFTWARE. | |
17 | */ | |
18 | ||
19 | #include "dhcpd.h" | |
20 | #include "privsep.h" | |
21 | ||
22 | struct buf * | |
23 | buf_open(size_t len) | |
24 | { | |
25 | struct buf *buf; | |
26 | ||
27 | if ((buf = calloc(1, sizeof(struct buf))) == NULL) | |
28 | error("buf_open: %m"); | |
29 | if ((buf->buf = malloc(len)) == NULL) { | |
30 | free(buf); | |
31 | error("buf_open: %m"); | |
32 | } | |
33 | buf->size = len; | |
34 | ||
35 | return (buf); | |
36 | } | |
37 | ||
38 | void | |
39 | buf_add(struct buf *buf, void *data, size_t len) | |
40 | { | |
41 | if (len == 0) | |
42 | return; | |
43 | ||
44 | if (buf->wpos + len > buf->size) | |
45 | error("buf_add: %m"); | |
46 | ||
47 | memcpy(buf->buf + buf->wpos, data, len); | |
48 | buf->wpos += len; | |
49 | } | |
50 | ||
51 | void | |
52 | buf_close(int sock, struct buf *buf) | |
53 | { | |
54 | ssize_t n; | |
55 | ||
56 | do { | |
57 | n = write(sock, buf->buf + buf->rpos, buf->size - buf->rpos); | |
58 | if (n == 0) /* connection closed */ | |
59 | error("buf_close (connection closed)"); | |
60 | if (n != -1 && n < buf->size - buf->rpos) | |
61 | error("buf_close (short write): %m"); | |
62 | ||
63 | } while (n == -1 && (errno == EAGAIN || errno == EINTR)); | |
64 | ||
65 | if (n == -1) | |
66 | error("buf_close: %m"); | |
67 | ||
68 | free(buf->buf); | |
69 | free(buf); | |
70 | } | |
71 | ||
72 | void | |
73 | buf_read(int sock, void *buf, size_t nbytes) | |
74 | { | |
75 | ssize_t n; | |
76 | ||
77 | do { | |
78 | n = read(sock, buf, nbytes); | |
79 | if (n == 0) { /* connection closed */ | |
4cada237 | 80 | #ifdef DEBUG |
846204b6 | 81 | debug("buf_read (connection closed)"); |
4cada237 | 82 | #endif |
846204b6 HT |
83 | exit(1); |
84 | } | |
85 | if (n != -1 && n < nbytes) | |
86 | error("buf_read (short read): %m"); | |
87 | } while (n == -1 && (errno == EINTR || errno == EAGAIN)); | |
88 | ||
89 | if (n == -1) | |
90 | error("buf_read: %m"); | |
91 | } | |
92 | ||
93 | void | |
94 | dispatch_imsg(int fd) | |
95 | { | |
96 | struct imsg_hdr hdr; | |
7cbe3601 | 97 | char *reason, *filename, |
846204b6 | 98 | *servername, *prefix; |
7cbe3601 | 99 | size_t reason_len, filename_len, |
846204b6 HT |
100 | servername_len, prefix_len, totlen; |
101 | struct client_lease lease; | |
102 | int ret, i, optlen; | |
103 | struct buf *buf; | |
104 | ||
105 | buf_read(fd, &hdr, sizeof(hdr)); | |
106 | ||
107 | switch (hdr.code) { | |
108 | case IMSG_SCRIPT_INIT: | |
109 | if (hdr.len < sizeof(hdr) + sizeof(size_t)) | |
110 | error("corrupted message received"); | |
846204b6 | 111 | buf_read(fd, &reason_len, sizeof(reason_len)); |
7cbe3601 | 112 | if (hdr.len < reason_len + sizeof(hdr) + sizeof(size_t) || |
846204b6 HT |
113 | reason_len == SIZE_T_MAX) |
114 | error("corrupted message received"); | |
115 | if (reason_len > 0) { | |
116 | if ((reason = calloc(1, reason_len + 1)) == NULL) | |
117 | error("%m"); | |
118 | buf_read(fd, reason, reason_len); | |
119 | } else | |
120 | reason = NULL; | |
121 | ||
7cbe3601 | 122 | priv_script_init(reason); |
846204b6 | 123 | free(reason); |
846204b6 HT |
124 | break; |
125 | case IMSG_SCRIPT_WRITE_PARAMS: | |
126 | bzero(&lease, sizeof lease); | |
127 | totlen = sizeof(hdr) + sizeof(lease) + sizeof(size_t); | |
128 | if (hdr.len < totlen) | |
129 | error("corrupted message received"); | |
130 | buf_read(fd, &lease, sizeof(lease)); | |
131 | ||
132 | buf_read(fd, &filename_len, sizeof(filename_len)); | |
133 | totlen += filename_len + sizeof(size_t); | |
134 | if (hdr.len < totlen || filename_len == SIZE_T_MAX) | |
135 | error("corrupted message received"); | |
136 | if (filename_len > 0) { | |
137 | if ((filename = calloc(1, filename_len + 1)) == NULL) | |
138 | error("%m"); | |
139 | buf_read(fd, filename, filename_len); | |
140 | } else | |
141 | filename = NULL; | |
142 | ||
143 | buf_read(fd, &servername_len, sizeof(servername_len)); | |
144 | totlen += servername_len + sizeof(size_t); | |
145 | if (hdr.len < totlen || servername_len == SIZE_T_MAX) | |
146 | error("corrupted message received"); | |
147 | if (servername_len > 0) { | |
148 | if ((servername = | |
149 | calloc(1, servername_len + 1)) == NULL) | |
150 | error("%m"); | |
151 | buf_read(fd, servername, servername_len); | |
152 | } else | |
153 | servername = NULL; | |
154 | ||
155 | buf_read(fd, &prefix_len, sizeof(prefix_len)); | |
156 | totlen += prefix_len; | |
157 | if (hdr.len < totlen || prefix_len == SIZE_T_MAX) | |
158 | error("corrupted message received"); | |
159 | if (prefix_len > 0) { | |
160 | if ((prefix = calloc(1, prefix_len + 1)) == NULL) | |
161 | error("%m"); | |
162 | buf_read(fd, prefix, prefix_len); | |
163 | } else | |
164 | prefix = NULL; | |
165 | ||
166 | for (i = 0; i < 256; i++) { | |
167 | totlen += sizeof(optlen); | |
168 | if (hdr.len < totlen) | |
169 | error("corrupted message received"); | |
170 | buf_read(fd, &optlen, sizeof(optlen)); | |
171 | lease.options[i].data = NULL; | |
172 | lease.options[i].len = optlen; | |
173 | if (optlen > 0) { | |
174 | totlen += optlen; | |
175 | if (hdr.len < totlen || optlen == SIZE_T_MAX) | |
176 | error("corrupted message received"); | |
177 | lease.options[i].data = | |
178 | calloc(1, optlen + 1); | |
179 | if (lease.options[i].data == NULL) | |
180 | error("%m"); | |
181 | buf_read(fd, lease.options[i].data, optlen); | |
182 | } | |
183 | } | |
184 | lease.server_name = servername; | |
185 | lease.filename = filename; | |
186 | ||
187 | priv_script_write_params(prefix, &lease); | |
188 | ||
189 | free(servername); | |
190 | free(filename); | |
191 | free(prefix); | |
192 | for (i = 0; i < 256; i++) | |
193 | if (lease.options[i].len > 0) | |
194 | free(lease.options[i].data); | |
195 | break; | |
196 | case IMSG_SCRIPT_GO: | |
197 | if (hdr.len != sizeof(hdr)) | |
198 | error("corrupted message received"); | |
199 | ||
200 | ret = priv_script_go(); | |
201 | ||
202 | hdr.code = IMSG_SCRIPT_GO_RET; | |
203 | hdr.len = sizeof(struct imsg_hdr) + sizeof(int); | |
204 | if ((buf = buf_open(hdr.len)) == NULL) | |
205 | error("buf_open: %m"); | |
206 | buf_add(buf, &hdr, sizeof(hdr)); | |
207 | buf_add(buf, &ret, sizeof(ret)); | |
208 | buf_close(fd, buf); | |
209 | break; | |
210 | default: | |
211 | error("received unknown message, code %d", hdr.code); | |
212 | } | |
213 | } |