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1 | /* $Id$ | |
2 | * | |
3 | * Copyright (C) 1988-1998 by the Massachusetts Institute of Technology. | |
4 | * For copying and distribution information, please see the file | |
5 | * <mit-copyright.h>. | |
6 | */ | |
7 | ||
8 | #include <mit-copyright.h> | |
9 | #include <moira.h> | |
10 | #include "update_server.h" | |
11 | #include "update.h" | |
12 | ||
13 | #include <errno.h> | |
14 | #include <fcntl.h> | |
15 | #include <stdio.h> | |
16 | #include <stdlib.h> | |
17 | #include <string.h> | |
18 | #include <unistd.h> | |
19 | ||
20 | #include <des.h> | |
21 | ||
22 | RCSID("$Header$"); | |
23 | ||
24 | #ifndef MIN | |
25 | #define MIN(a, b) (((a) < (b)) ? (a) : (b)) | |
26 | #endif /* MIN */ | |
27 | ||
28 | static des_key_schedule sched; | |
29 | static des_cblock ivec; | |
30 | extern des_cblock session; | |
31 | ||
32 | static int get_block(int conn, int fd, int max_size, int encrypt); | |
33 | ||
34 | /* | |
35 | * get_file() | |
36 | * | |
37 | * arguments: | |
38 | * char *pathname | |
39 | * file to receive | |
40 | * int file_size | |
41 | * number of bytes | |
42 | * int checksum | |
43 | * linear checksum of bytes | |
44 | * | |
45 | * syntax: | |
46 | * (initial protocol already done) | |
47 | * <<< (int)code (can we accept the file?) | |
48 | * >>> (STRING)data | |
49 | * <<< (int)code | |
50 | * >>> (STRING)data | |
51 | * <<< (int)code | |
52 | * ... | |
53 | * >>> (STRING)data (last data block) | |
54 | * <<< (int)code (from read, write, checksum verify) | |
55 | * | |
56 | * returns: | |
57 | * int | |
58 | * 0 for success, 1 for failure | |
59 | * | |
60 | * function: | |
61 | * perform initial preparations and receive file as | |
62 | * a single string, storing it into <pathname> | |
63 | * | |
64 | */ | |
65 | ||
66 | int get_file(int conn, char *pathname, int file_size, int checksum, | |
67 | int mode, int encrypt) | |
68 | { | |
69 | int fd, n_written, code; | |
70 | int found_checksum; | |
71 | char buf[BUFSIZ]; | |
72 | ||
73 | if (!have_authorization) | |
74 | { | |
75 | send_int(conn, MR_PERM); | |
76 | return 1; | |
77 | } | |
78 | if (setuid(uid) < 0) | |
79 | { | |
80 | com_err(whoami, errno, "Unable to setuid to %d\n", uid); | |
81 | exit(1); | |
82 | } | |
83 | ||
84 | /* unlink old file */ | |
85 | if (!config_lookup("noclobber")) | |
86 | unlink(pathname); | |
87 | /* open file descriptor */ | |
88 | fd = open(pathname, O_CREAT|O_EXCL|O_WRONLY, mode); | |
89 | if (fd == -1) | |
90 | { | |
91 | code = errno; | |
92 | com_err(whoami, errno, "creating file %s (get_file)", pathname); | |
93 | send_int(conn, code); | |
94 | if (setuid(0) < 0) | |
95 | { | |
96 | com_err(whoami, errno, "Unable to setuid back to %d\n", 0); | |
97 | exit(1); | |
98 | } | |
99 | return 1; | |
100 | } | |
101 | ||
102 | /* check to see if we've got the disk space */ | |
103 | n_written = 0; | |
104 | while (n_written < file_size) | |
105 | { | |
106 | int n_wrote; | |
107 | n_wrote = write(fd, buf, sizeof(buf)); | |
108 | if (n_wrote == -1) | |
109 | { | |
110 | code = errno; | |
111 | com_err(whoami, code, "verifying free disk space for %s (get_file)", | |
112 | pathname); | |
113 | send_int(conn, code); | |
114 | ||
115 | /* do all we can to free the space */ | |
116 | unlink(pathname); | |
117 | ftruncate(fd, 0); | |
118 | close(fd); | |
119 | ||
120 | if (setuid(0) < 0) | |
121 | { | |
122 | com_err(whoami, errno, "Unable to setuid back to %d\n", 0); | |
123 | exit(1); | |
124 | } | |
125 | return 1; | |
126 | } | |
127 | n_written += n_wrote; | |
128 | } | |
129 | ||
130 | lseek(fd, 0, SEEK_SET); | |
131 | send_ok(conn); | |
132 | ||
133 | if (encrypt) | |
134 | { | |
135 | des_key_sched(session, sched); | |
136 | memcpy(ivec, session, sizeof(ivec)); | |
137 | } | |
138 | ||
139 | n_written = 0; | |
140 | while (n_written < file_size) | |
141 | { | |
142 | int n_got = get_block(conn, fd, file_size - n_written, encrypt); | |
143 | ||
144 | if (n_got == -1) | |
145 | { | |
146 | /* get_block has already printed a message */ | |
147 | unlink(pathname); | |
148 | if (setuid(0) < 0) | |
149 | { | |
150 | com_err(whoami, errno, "Unable to setuid back to %d\n", 0); | |
151 | exit(1); | |
152 | } | |
153 | return 1; | |
154 | } | |
155 | n_written += n_got; | |
156 | if (n_written != file_size) | |
157 | send_ok(conn); | |
158 | } | |
159 | ||
160 | fsync(fd); | |
161 | ftruncate(fd, file_size); | |
162 | fsync(fd); | |
163 | close(fd); | |
164 | ||
165 | if (setuid(0) < 0) | |
166 | { | |
167 | com_err(whoami, errno, "Unable to setuid back to %d\n", 0); | |
168 | exit(1); | |
169 | } | |
170 | ||
171 | /* validate checksum */ | |
172 | found_checksum = checksum_file(pathname); | |
173 | if (checksum != found_checksum) | |
174 | { | |
175 | code = MR_MISSINGFILE; | |
176 | com_err(whoami, code, ": expected = %d, found = %d", | |
177 | checksum, found_checksum); | |
178 | send_int(conn, code); | |
179 | return 1; | |
180 | } | |
181 | ||
182 | send_ok(conn); | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static int get_block(int conn, int fd, int max_size, int encrypt) | |
187 | { | |
188 | char *data; | |
189 | size_t len; | |
190 | int n_read, n, i, code; | |
191 | ||
192 | recv_string(conn, &data, &len); | |
193 | ||
194 | if (encrypt) | |
195 | { | |
196 | char *unenc = malloc(len); | |
197 | ||
198 | if (!unenc) | |
199 | { | |
200 | send_int(conn, ENOMEM); | |
201 | return -1; | |
202 | } | |
203 | ||
204 | des_pcbc_encrypt(data, unenc, len, sched, ivec, 1); | |
205 | for (i = 0; i < 8; i++) | |
206 | ivec[i] = data[len - 8 + i] ^ unenc[len - 8 + i]; | |
207 | free(data); | |
208 | data = unenc; | |
209 | } | |
210 | ||
211 | n_read = MIN(len, max_size); | |
212 | n = 0; | |
213 | while (n < n_read) | |
214 | { | |
215 | int n_wrote; | |
216 | n_wrote = write(fd, data + n, n_read - n); | |
217 | if (n_wrote == -1) | |
218 | { | |
219 | code = errno; | |
220 | com_err(whoami, errno, "writing file (get_file)"); | |
221 | send_int(conn, code); | |
222 | free(data); | |
223 | close(fd); | |
224 | return -1; | |
225 | } | |
226 | n += n_wrote; | |
227 | } | |
228 | free(data); | |
229 | return n; | |
230 | } |