Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * iovec manipulation routines. | |
3 | * | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; either version | |
8 | * 2 of the License, or (at your option) any later version. | |
9 | * | |
10 | * Fixes: | |
11 | * Andrew Lunn : Errors in iovec copying. | |
12 | * Pedro Roque : Added memcpy_fromiovecend and | |
13 | * csum_..._fromiovecend. | |
14 | * Andi Kleen : fixed error handling for 2.1 | |
15 | * Alexey Kuznetsov: 2.1 optimisations | |
16 | * Andi Kleen : Fix csum*fromiovecend for IPv6. | |
17 | */ | |
18 | ||
19 | #include <linux/errno.h> | |
20 | #include <linux/module.h> | |
1da177e4 LT |
21 | #include <linux/kernel.h> |
22 | #include <linux/mm.h> | |
1da177e4 LT |
23 | #include <linux/net.h> |
24 | #include <linux/in6.h> | |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/byteorder.h> | |
27 | #include <net/checksum.h> | |
28 | #include <net/sock.h> | |
29 | ||
30 | /* | |
31 | * Verify iovec. The caller must ensure that the iovec is big enough | |
32 | * to hold the message iovec. | |
33 | * | |
e49332bd | 34 | * Save time not doing access_ok. copy_*_user will make this work |
1da177e4 LT |
35 | * in any case. |
36 | */ | |
37 | ||
43db362d | 38 | int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode) |
1da177e4 | 39 | { |
8acfe468 | 40 | int size, ct, err; |
4ec93edb | 41 | |
1da177e4 LT |
42 | if (m->msg_namelen) { |
43 | if (mode == VERIFY_READ) { | |
a700d8be NK |
44 | void __user *namep; |
45 | namep = (void __user __force *) m->msg_name; | |
46 | err = move_addr_to_kernel(namep, m->msg_namelen, | |
1da177e4 LT |
47 | address); |
48 | if (err < 0) | |
49 | return err; | |
50 | } | |
51 | m->msg_name = address; | |
52 | } else { | |
53 | m->msg_name = NULL; | |
54 | } | |
55 | ||
56 | size = m->msg_iovlen * sizeof(struct iovec); | |
a700d8be | 57 | if (copy_from_user(iov, (void __user __force *) m->msg_iov, size)) |
1da177e4 LT |
58 | return -EFAULT; |
59 | ||
60 | m->msg_iov = iov; | |
61 | err = 0; | |
62 | ||
63 | for (ct = 0; ct < m->msg_iovlen; ct++) { | |
8acfe468 DM |
64 | size_t len = iov[ct].iov_len; |
65 | ||
66 | if (len > INT_MAX - err) { | |
67 | len = INT_MAX - err; | |
68 | iov[ct].iov_len = len; | |
69 | } | |
70 | err += len; | |
1da177e4 LT |
71 | } |
72 | ||
73 | return err; | |
74 | } | |
75 | ||
0a1ec07a MT |
76 | /* |
77 | * Copy kernel to iovec. Returns -EFAULT on error. | |
78 | */ | |
79 | ||
80 | int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, | |
81 | int offset, int len) | |
82 | { | |
83 | int copy; | |
84 | for (; len > 0; ++iov) { | |
85 | /* Skip over the finished iovecs */ | |
86 | if (unlikely(offset >= iov->iov_len)) { | |
87 | offset -= iov->iov_len; | |
88 | continue; | |
89 | } | |
90 | copy = min_t(unsigned int, iov->iov_len - offset, len); | |
2faef52b | 91 | if (copy_to_user(iov->iov_base + offset, kdata, copy)) |
0a1ec07a | 92 | return -EFAULT; |
2faef52b | 93 | offset = 0; |
0a1ec07a MT |
94 | kdata += copy; |
95 | len -= copy; | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } | |
9e34a5b5 | 100 | EXPORT_SYMBOL(memcpy_toiovecend); |
0a1ec07a | 101 | |
1da177e4 | 102 | /* |
6f26c9a7 | 103 | * Copy iovec from kernel. Returns -EFAULT on error. |
1da177e4 | 104 | */ |
6f26c9a7 MT |
105 | |
106 | int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, | |
107 | int offset, int len) | |
1da177e4 LT |
108 | { |
109 | /* Skip over the finished iovecs */ | |
110 | while (offset >= iov->iov_len) { | |
111 | offset -= iov->iov_len; | |
112 | iov++; | |
113 | } | |
114 | ||
115 | while (len > 0) { | |
116 | u8 __user *base = iov->iov_base + offset; | |
117 | int copy = min_t(unsigned int, len, iov->iov_len - offset); | |
118 | ||
119 | offset = 0; | |
120 | if (copy_from_user(kdata, base, copy)) | |
121 | return -EFAULT; | |
122 | len -= copy; | |
123 | kdata += copy; | |
124 | iov++; | |
125 | } | |
126 | ||
127 | return 0; | |
128 | } | |
9e34a5b5 | 129 | EXPORT_SYMBOL(memcpy_fromiovecend); |
1da177e4 LT |
130 | |
131 | /* | |
132 | * And now for the all-in-one: copy and checksum from a user iovec | |
133 | * directly to a datagram | |
134 | * Calls to csum_partial but the last must be in 32 bit chunks | |
135 | * | |
136 | * ip_build_xmit must ensure that when fragmenting only the last | |
137 | * call to this function will be unaligned also. | |
138 | */ | |
139 | int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov, | |
44bb9363 | 140 | int offset, unsigned int len, __wsum *csump) |
1da177e4 | 141 | { |
44bb9363 | 142 | __wsum csum = *csump; |
1da177e4 LT |
143 | int partial_cnt = 0, err = 0; |
144 | ||
145 | /* Skip over the finished iovecs */ | |
146 | while (offset >= iov->iov_len) { | |
147 | offset -= iov->iov_len; | |
148 | iov++; | |
149 | } | |
150 | ||
151 | while (len > 0) { | |
152 | u8 __user *base = iov->iov_base + offset; | |
153 | int copy = min_t(unsigned int, len, iov->iov_len - offset); | |
154 | ||
155 | offset = 0; | |
156 | ||
157 | /* There is a remnant from previous iov. */ | |
158 | if (partial_cnt) { | |
159 | int par_len = 4 - partial_cnt; | |
160 | ||
161 | /* iov component is too short ... */ | |
162 | if (par_len > copy) { | |
163 | if (copy_from_user(kdata, base, copy)) | |
164 | goto out_fault; | |
165 | kdata += copy; | |
166 | base += copy; | |
167 | partial_cnt += copy; | |
168 | len -= copy; | |
169 | iov++; | |
170 | if (len) | |
171 | continue; | |
172 | *csump = csum_partial(kdata - partial_cnt, | |
173 | partial_cnt, csum); | |
174 | goto out; | |
175 | } | |
176 | if (copy_from_user(kdata, base, par_len)) | |
177 | goto out_fault; | |
178 | csum = csum_partial(kdata - partial_cnt, 4, csum); | |
179 | kdata += par_len; | |
180 | base += par_len; | |
181 | copy -= par_len; | |
182 | len -= par_len; | |
183 | partial_cnt = 0; | |
184 | } | |
185 | ||
186 | if (len > copy) { | |
187 | partial_cnt = copy % 4; | |
188 | if (partial_cnt) { | |
189 | copy -= partial_cnt; | |
190 | if (copy_from_user(kdata + copy, base + copy, | |
4ec93edb | 191 | partial_cnt)) |
1da177e4 LT |
192 | goto out_fault; |
193 | } | |
194 | } | |
195 | ||
196 | if (copy) { | |
197 | csum = csum_and_copy_from_user(base, kdata, copy, | |
198 | csum, &err); | |
199 | if (err) | |
200 | goto out; | |
201 | } | |
202 | len -= copy + partial_cnt; | |
203 | kdata += copy + partial_cnt; | |
204 | iov++; | |
205 | } | |
4ec93edb | 206 | *csump = csum; |
1da177e4 LT |
207 | out: |
208 | return err; | |
209 | ||
210 | out_fault: | |
211 | err = -EFAULT; | |
212 | goto out; | |
213 | } | |
1da177e4 | 214 | EXPORT_SYMBOL(csum_partial_copy_fromiovecend); |