Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/kernel.h> |
| 22 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Jesper Juhl | e49332b | 2005-05-01 08:59:08 -0700 | [diff] [blame] | 34 | * Save time not doing access_ok. copy_*_user will make this work |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | * in any case. |
| 36 | */ |
| 37 | |
Maciej Żenczykowski | 43db362 | 2012-03-11 12:51:50 +0000 | [diff] [blame] | 38 | int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | { |
Al Viro | 0844932 | 2014-11-09 22:33:45 -0500 | [diff] [blame^] | 40 | struct iovec *res; |
| 41 | int err; |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 42 | |
Andrey Ryabinin | 40eea80 | 2014-07-26 21:26:58 +0400 | [diff] [blame] | 43 | if (m->msg_name && m->msg_namelen) { |
Al Viro | 0844932 | 2014-11-09 22:33:45 -0500 | [diff] [blame^] | 44 | if (mode == WRITE) { |
| 45 | void __user *namep = (void __user __force *)m->msg_name; |
| 46 | int err = move_addr_to_kernel(namep, m->msg_namelen, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | address); |
| 48 | if (err < 0) |
| 49 | return err; |
| 50 | } |
Andrey Ryabinin | 40eea80 | 2014-07-26 21:26:58 +0400 | [diff] [blame] | 51 | m->msg_name = address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | } else { |
| 53 | m->msg_name = NULL; |
Andrey Ryabinin | 40eea80 | 2014-07-26 21:26:58 +0400 | [diff] [blame] | 54 | m->msg_namelen = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | } |
Al Viro | 0844932 | 2014-11-09 22:33:45 -0500 | [diff] [blame^] | 56 | if (m->msg_iovlen > UIO_MAXIOV) |
| 57 | return -EMSGSIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Al Viro | 0844932 | 2014-11-09 22:33:45 -0500 | [diff] [blame^] | 59 | err = rw_copy_check_uvector(mode, (void __user __force *)m->msg_iov, |
| 60 | m->msg_iovlen, UIO_FASTIOV, iov, &res); |
| 61 | if (err >= 0) |
| 62 | m->msg_iov = res; |
| 63 | else if (res != iov) |
| 64 | kfree(res); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | return err; |
| 66 | } |
| 67 | |
| 68 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | * And now for the all-in-one: copy and checksum from a user iovec |
| 70 | * directly to a datagram |
| 71 | * Calls to csum_partial but the last must be in 32 bit chunks |
| 72 | * |
| 73 | * ip_build_xmit must ensure that when fragmenting only the last |
| 74 | * call to this function will be unaligned also. |
| 75 | */ |
| 76 | int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov, |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 77 | int offset, unsigned int len, __wsum *csump) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | { |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 79 | __wsum csum = *csump; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | int partial_cnt = 0, err = 0; |
| 81 | |
| 82 | /* Skip over the finished iovecs */ |
| 83 | while (offset >= iov->iov_len) { |
| 84 | offset -= iov->iov_len; |
| 85 | iov++; |
| 86 | } |
| 87 | |
| 88 | while (len > 0) { |
| 89 | u8 __user *base = iov->iov_base + offset; |
| 90 | int copy = min_t(unsigned int, len, iov->iov_len - offset); |
| 91 | |
| 92 | offset = 0; |
| 93 | |
| 94 | /* There is a remnant from previous iov. */ |
| 95 | if (partial_cnt) { |
| 96 | int par_len = 4 - partial_cnt; |
| 97 | |
| 98 | /* iov component is too short ... */ |
| 99 | if (par_len > copy) { |
| 100 | if (copy_from_user(kdata, base, copy)) |
| 101 | goto out_fault; |
| 102 | kdata += copy; |
| 103 | base += copy; |
| 104 | partial_cnt += copy; |
| 105 | len -= copy; |
| 106 | iov++; |
| 107 | if (len) |
| 108 | continue; |
| 109 | *csump = csum_partial(kdata - partial_cnt, |
| 110 | partial_cnt, csum); |
| 111 | goto out; |
| 112 | } |
| 113 | if (copy_from_user(kdata, base, par_len)) |
| 114 | goto out_fault; |
| 115 | csum = csum_partial(kdata - partial_cnt, 4, csum); |
| 116 | kdata += par_len; |
| 117 | base += par_len; |
| 118 | copy -= par_len; |
| 119 | len -= par_len; |
| 120 | partial_cnt = 0; |
| 121 | } |
| 122 | |
| 123 | if (len > copy) { |
| 124 | partial_cnt = copy % 4; |
| 125 | if (partial_cnt) { |
| 126 | copy -= partial_cnt; |
| 127 | if (copy_from_user(kdata + copy, base + copy, |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 128 | partial_cnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | goto out_fault; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | if (copy) { |
| 134 | csum = csum_and_copy_from_user(base, kdata, copy, |
| 135 | csum, &err); |
| 136 | if (err) |
| 137 | goto out; |
| 138 | } |
| 139 | len -= copy + partial_cnt; |
| 140 | kdata += copy + partial_cnt; |
| 141 | iov++; |
| 142 | } |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 143 | *csump = csum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | out: |
| 145 | return err; |
| 146 | |
| 147 | out_fault: |
| 148 | err = -EFAULT; |
| 149 | goto out; |
| 150 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | EXPORT_SYMBOL(csum_partial_copy_fromiovecend); |
Jason Wang | b4bf077 | 2013-08-06 17:45:03 +0800 | [diff] [blame] | 152 | |
| 153 | unsigned long iov_pages(const struct iovec *iov, int offset, |
| 154 | unsigned long nr_segs) |
| 155 | { |
| 156 | unsigned long seg, base; |
| 157 | int pages = 0, len, size; |
| 158 | |
| 159 | while (nr_segs && (offset >= iov->iov_len)) { |
| 160 | offset -= iov->iov_len; |
| 161 | ++iov; |
| 162 | --nr_segs; |
| 163 | } |
| 164 | |
| 165 | for (seg = 0; seg < nr_segs; seg++) { |
| 166 | base = (unsigned long)iov[seg].iov_base + offset; |
| 167 | len = iov[seg].iov_len - offset; |
| 168 | size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; |
| 169 | pages += size; |
| 170 | offset = 0; |
| 171 | } |
| 172 | |
| 173 | return pages; |
| 174 | } |
| 175 | EXPORT_SYMBOL(iov_pages); |