]>
Commit | Line | Data |
---|---|---|
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 | #ifdef HAVE_KRB4 | |
21 | #include <des.h> | |
22 | #endif | |
23 | ||
24 | RCSID("$Header$"); | |
25 | ||
26 | #ifndef MIN | |
27 | #define MIN(a, b) (((a) < (b)) ? (a) : (b)) | |
28 | #endif /* MIN */ | |
29 | ||
30 | #ifdef HAVE_KRB4 | |
31 | static des_key_schedule sched; | |
32 | static des_cblock ivec; | |
33 | extern des_cblock session; | |
34 | #endif | |
35 | ||
36 | static int get_block(int conn, int fd, int max_size, int encrypt); | |
37 | ||
38 | /* | |
39 | * get_file() | |
40 | * | |
41 | * arguments: | |
42 | * char *pathname | |
43 | * file to receive | |
44 | * int file_size | |
45 | * number of bytes | |
46 | * int checksum | |
47 | * linear checksum of bytes | |
48 | * | |
49 | * syntax: | |
50 | * (initial protocol already done) | |
51 | * <<< (int)code (can we accept the file?) | |
52 | * >>> (STRING)data | |
53 | * <<< (int)code | |
54 | * >>> (STRING)data | |
55 | * <<< (int)code | |
56 | * ... | |
57 | * >>> (STRING)data (last data block) | |
58 | * <<< (int)code (from read, write, checksum verify) | |
59 | * | |
60 | * returns: | |
61 | * int | |
62 | * 0 for success, 1 for failure | |
63 | * | |
64 | * function: | |
65 | * perform initial preparations and receive file as | |
66 | * a single string, storing it into <pathname> | |
67 | * | |
68 | */ | |
69 | ||
70 | int get_file(int conn, char *pathname, int file_size, int checksum, | |
71 | int mode, int encrypt) | |
72 | { | |
73 | int fd, n_written, code; | |
74 | int found_checksum; | |
75 | char buf[BUFSIZ]; | |
76 | ||
77 | memset(buf, '\0', sizeof(buf)); | |
78 | ||
79 | if (!have_authorization) | |
80 | { | |
81 | send_int(conn, MR_PERM); | |
82 | return 1; | |
83 | } | |
84 | if (setuid(uid) < 0) | |
85 | { | |
86 | com_err(whoami, errno, "Unable to setuid to %d\n", uid); | |
87 | exit(1); | |
88 | } | |
89 | ||
90 | /* unlink old file */ | |
91 | if (!config_lookup("noclobber")) | |
92 | unlink(pathname); | |
93 | /* open file descriptor */ | |
94 | fd = open(pathname, O_CREAT|O_EXCL|O_WRONLY, mode); | |
95 | if (fd == -1) | |
96 | { | |
97 | code = errno; | |
98 | com_err(whoami, errno, "creating file %s (get_file)", pathname); | |
99 | send_int(conn, code); | |
100 | return 1; | |
101 | } | |
102 | ||
103 | /* check to see if we've got the disk space */ | |
104 | n_written = 0; | |
105 | while (n_written < file_size) | |
106 | { | |
107 | int n_wrote; | |
108 | n_wrote = write(fd, buf, sizeof(buf)); | |
109 | if (n_wrote == -1) | |
110 | { | |
111 | code = errno; | |
112 | com_err(whoami, code, "verifying free disk space for %s (get_file)", | |
113 | pathname); | |
114 | send_int(conn, code); | |
115 | ||
116 | /* do all we can to free the space */ | |
117 | unlink(pathname); | |
118 | ftruncate(fd, 0); | |
119 | close(fd); | |
120 | return 1; | |
121 | } | |
122 | n_written += n_wrote; | |
123 | } | |
124 | ||
125 | lseek(fd, 0, SEEK_SET); | |
126 | send_ok(conn); | |
127 | ||
128 | if (encrypt) | |
129 | { | |
130 | #ifdef HAVE_KRB4 | |
131 | des_key_sched(session, sched); | |
132 | memcpy(ivec, session, sizeof(ivec)); | |
133 | #else | |
134 | /* The session key only gets stored if auth happens in krb4 to | |
135 | begin with. If you don't have krb4, you can't possibly be | |
136 | coming up with a valid session key. */ | |
137 | return MR_NO_KRB4; | |
138 | #endif | |
139 | } | |
140 | ||
141 | n_written = 0; | |
142 | while (n_written < file_size) | |
143 | { | |
144 | int n_got = get_block(conn, fd, file_size - n_written, encrypt); | |
145 | ||
146 | if (n_got == -1) | |
147 | { | |
148 | /* get_block has already printed a message */ | |
149 | unlink(pathname); | |
150 | return 1; | |
151 | } | |
152 | n_written += n_got; | |
153 | if (n_written != file_size) | |
154 | send_ok(conn); | |
155 | } | |
156 | ||
157 | fsync(fd); | |
158 | ftruncate(fd, file_size); | |
159 | fsync(fd); | |
160 | close(fd); | |
161 | ||
162 | /* validate checksum */ | |
163 | found_checksum = checksum_file(pathname); | |
164 | if (checksum != found_checksum) | |
165 | { | |
166 | code = MR_MISSINGFILE; | |
167 | com_err(whoami, code, ": expected = %d, found = %d", | |
168 | checksum, found_checksum); | |
169 | send_int(conn, code); | |
170 | return 1; | |
171 | } | |
172 | ||
173 | send_ok(conn); | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static int get_block(int conn, int fd, int max_size, int encrypt) | |
178 | { | |
179 | char *data; | |
180 | size_t len; | |
181 | int n_read, n, i, code; | |
182 | ||
183 | recv_string(conn, &data, &len); | |
184 | ||
185 | if (encrypt) | |
186 | { | |
187 | #ifdef HAVE_KRB4 | |
188 | char *unenc = malloc(len); | |
189 | ||
190 | if (!unenc) | |
191 | { | |
192 | send_int(conn, ENOMEM); | |
193 | return -1; | |
194 | } | |
195 | ||
196 | des_pcbc_encrypt(data, unenc, len, sched, ivec, 1); | |
197 | for (i = 0; i < 8; i++) | |
198 | ivec[i] = data[len - 8 + i] ^ unenc[len - 8 + i]; | |
199 | free(data); | |
200 | data = unenc; | |
201 | #endif | |
202 | } | |
203 | ||
204 | n_read = MIN(len, max_size); | |
205 | n = 0; | |
206 | while (n < n_read) | |
207 | { | |
208 | int n_wrote; | |
209 | n_wrote = write(fd, data + n, n_read - n); | |
210 | if (n_wrote == -1) | |
211 | { | |
212 | code = errno; | |
213 | com_err(whoami, errno, "writing file (get_file)"); | |
214 | send_int(conn, code); | |
215 | free(data); | |
216 | close(fd); | |
217 | return -1; | |
218 | } | |
219 | n += n_wrote; | |
220 | } | |
221 | free(data); | |
222 | return n; | |
223 | } |