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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 | } | |
f3d33426 HFS |
51 | if (m->msg_name) |
52 | m->msg_name = address; | |
1da177e4 LT |
53 | } else { |
54 | m->msg_name = NULL; | |
55 | } | |
56 | ||
57 | size = m->msg_iovlen * sizeof(struct iovec); | |
a700d8be | 58 | if (copy_from_user(iov, (void __user __force *) m->msg_iov, size)) |
1da177e4 LT |
59 | return -EFAULT; |
60 | ||
61 | m->msg_iov = iov; | |
62 | err = 0; | |
63 | ||
64 | for (ct = 0; ct < m->msg_iovlen; ct++) { | |
8acfe468 DM |
65 | size_t len = iov[ct].iov_len; |
66 | ||
67 | if (len > INT_MAX - err) { | |
68 | len = INT_MAX - err; | |
69 | iov[ct].iov_len = len; | |
70 | } | |
71 | err += len; | |
1da177e4 LT |
72 | } |
73 | ||
74 | return err; | |
75 | } | |
76 | ||
0a1ec07a MT |
77 | /* |
78 | * Copy kernel to iovec. Returns -EFAULT on error. | |
79 | */ | |
80 | ||
81 | int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, | |
82 | int offset, int len) | |
83 | { | |
84 | int copy; | |
85 | for (; len > 0; ++iov) { | |
86 | /* Skip over the finished iovecs */ | |
87 | if (unlikely(offset >= iov->iov_len)) { | |
88 | offset -= iov->iov_len; | |
89 | continue; | |
90 | } | |
91 | copy = min_t(unsigned int, iov->iov_len - offset, len); | |
2faef52b | 92 | if (copy_to_user(iov->iov_base + offset, kdata, copy)) |
0a1ec07a | 93 | return -EFAULT; |
2faef52b | 94 | offset = 0; |
0a1ec07a MT |
95 | kdata += copy; |
96 | len -= copy; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
9e34a5b5 | 101 | EXPORT_SYMBOL(memcpy_toiovecend); |
0a1ec07a | 102 | |
1da177e4 | 103 | /* |
ab1a2d77 | 104 | * Copy iovec to kernel. Returns -EFAULT on error. |
1da177e4 | 105 | */ |
6f26c9a7 MT |
106 | |
107 | int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, | |
108 | int offset, int len) | |
1da177e4 LT |
109 | { |
110 | /* Skip over the finished iovecs */ | |
111 | while (offset >= iov->iov_len) { | |
112 | offset -= iov->iov_len; | |
113 | iov++; | |
114 | } | |
115 | ||
116 | while (len > 0) { | |
117 | u8 __user *base = iov->iov_base + offset; | |
118 | int copy = min_t(unsigned int, len, iov->iov_len - offset); | |
119 | ||
120 | offset = 0; | |
121 | if (copy_from_user(kdata, base, copy)) | |
122 | return -EFAULT; | |
123 | len -= copy; | |
124 | kdata += copy; | |
125 | iov++; | |
126 | } | |
127 | ||
128 | return 0; | |
129 | } | |
9e34a5b5 | 130 | EXPORT_SYMBOL(memcpy_fromiovecend); |
1da177e4 LT |
131 | |
132 | /* | |
133 | * And now for the all-in-one: copy and checksum from a user iovec | |
134 | * directly to a datagram | |
135 | * Calls to csum_partial but the last must be in 32 bit chunks | |
136 | * | |
137 | * ip_build_xmit must ensure that when fragmenting only the last | |
138 | * call to this function will be unaligned also. | |
139 | */ | |
140 | int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov, | |
44bb9363 | 141 | int offset, unsigned int len, __wsum *csump) |
1da177e4 | 142 | { |
44bb9363 | 143 | __wsum csum = *csump; |
1da177e4 LT |
144 | int partial_cnt = 0, err = 0; |
145 | ||
146 | /* Skip over the finished iovecs */ | |
147 | while (offset >= iov->iov_len) { | |
148 | offset -= iov->iov_len; | |
149 | iov++; | |
150 | } | |
151 | ||
152 | while (len > 0) { | |
153 | u8 __user *base = iov->iov_base + offset; | |
154 | int copy = min_t(unsigned int, len, iov->iov_len - offset); | |
155 | ||
156 | offset = 0; | |
157 | ||
158 | /* There is a remnant from previous iov. */ | |
159 | if (partial_cnt) { | |
160 | int par_len = 4 - partial_cnt; | |
161 | ||
162 | /* iov component is too short ... */ | |
163 | if (par_len > copy) { | |
164 | if (copy_from_user(kdata, base, copy)) | |
165 | goto out_fault; | |
166 | kdata += copy; | |
167 | base += copy; | |
168 | partial_cnt += copy; | |
169 | len -= copy; | |
170 | iov++; | |
171 | if (len) | |
172 | continue; | |
173 | *csump = csum_partial(kdata - partial_cnt, | |
174 | partial_cnt, csum); | |
175 | goto out; | |
176 | } | |
177 | if (copy_from_user(kdata, base, par_len)) | |
178 | goto out_fault; | |
179 | csum = csum_partial(kdata - partial_cnt, 4, csum); | |
180 | kdata += par_len; | |
181 | base += par_len; | |
182 | copy -= par_len; | |
183 | len -= par_len; | |
184 | partial_cnt = 0; | |
185 | } | |
186 | ||
187 | if (len > copy) { | |
188 | partial_cnt = copy % 4; | |
189 | if (partial_cnt) { | |
190 | copy -= partial_cnt; | |
191 | if (copy_from_user(kdata + copy, base + copy, | |
4ec93edb | 192 | partial_cnt)) |
1da177e4 LT |
193 | goto out_fault; |
194 | } | |
195 | } | |
196 | ||
197 | if (copy) { | |
198 | csum = csum_and_copy_from_user(base, kdata, copy, | |
199 | csum, &err); | |
200 | if (err) | |
201 | goto out; | |
202 | } | |
203 | len -= copy + partial_cnt; | |
204 | kdata += copy + partial_cnt; | |
205 | iov++; | |
206 | } | |
4ec93edb | 207 | *csump = csum; |
1da177e4 LT |
208 | out: |
209 | return err; | |
210 | ||
211 | out_fault: | |
212 | err = -EFAULT; | |
213 | goto out; | |
214 | } | |
1da177e4 | 215 | EXPORT_SYMBOL(csum_partial_copy_fromiovecend); |
b4bf0777 JW |
216 | |
217 | unsigned long iov_pages(const struct iovec *iov, int offset, | |
218 | unsigned long nr_segs) | |
219 | { | |
220 | unsigned long seg, base; | |
221 | int pages = 0, len, size; | |
222 | ||
223 | while (nr_segs && (offset >= iov->iov_len)) { | |
224 | offset -= iov->iov_len; | |
225 | ++iov; | |
226 | --nr_segs; | |
227 | } | |
228 | ||
229 | for (seg = 0; seg < nr_segs; seg++) { | |
230 | base = (unsigned long)iov[seg].iov_base + offset; | |
231 | len = iov[seg].iov_len - offset; | |
232 | size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; | |
233 | pages += size; | |
234 | offset = 0; | |
235 | } | |
236 | ||
237 | return pages; | |
238 | } | |
239 | EXPORT_SYMBOL(iov_pages); |