| /* |
| * iovec manipulation routines. |
| * |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Fixes: |
| * Andrew Lunn : Errors in iovec copying. |
| * Pedro Roque : Added memcpy_fromiovecend and |
| * csum_..._fromiovecend. |
| * Andi Kleen : fixed error handling for 2.1 |
| * Alexey Kuznetsov: 2.1 optimisations |
| * Andi Kleen : Fix csum*fromiovecend for IPv6. |
| */ |
| |
| #include <linux/errno.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/net.h> |
| #include <linux/in6.h> |
| #include <asm/uaccess.h> |
| #include <asm/byteorder.h> |
| #include <net/checksum.h> |
| #include <net/sock.h> |
| |
| /* |
| * Verify iovec. The caller must ensure that the iovec is big enough |
| * to hold the message iovec. |
| * |
| * Save time not doing access_ok. copy_*_user will make this work |
| * in any case. |
| */ |
| |
| int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode) |
| { |
| int size, err, ct; |
| |
| if (m->msg_namelen) { |
| if (mode == VERIFY_READ) { |
| err = move_addr_to_kernel(m->msg_name, m->msg_namelen, |
| address); |
| if (err < 0) |
| return err; |
| } |
| m->msg_name = address; |
| } else { |
| m->msg_name = NULL; |
| } |
| |
| size = m->msg_iovlen * sizeof(struct iovec); |
| if (copy_from_user(iov, m->msg_iov, size)) |
| return -EFAULT; |
| |
| m->msg_iov = iov; |
| err = 0; |
| |
| for (ct = 0; ct < m->msg_iovlen; ct++) { |
| size_t len = iov[ct].iov_len; |
| |
| if (len > INT_MAX - err) { |
| len = INT_MAX - err; |
| iov[ct].iov_len = len; |
| } |
| err += len; |
| } |
| |
| return err; |
| } |
| |
| /* |
| * Copy kernel to iovec. Returns -EFAULT on error. |
| * |
| * Note: this modifies the original iovec. |
| */ |
| |
| int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) |
| { |
| while (len > 0) { |
| if (iov->iov_len) { |
| int copy = min_t(unsigned int, iov->iov_len, len); |
| if (copy_to_user(iov->iov_base, kdata, copy)) |
| return -EFAULT; |
| kdata += copy; |
| len -= copy; |
| iov->iov_len -= copy; |
| iov->iov_base += copy; |
| } |
| iov++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Copy kernel to iovec. Returns -EFAULT on error. |
| */ |
| |
| int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, |
| int offset, int len) |
| { |
| int copy; |
| for (; len > 0; ++iov) { |
| /* Skip over the finished iovecs */ |
| if (unlikely(offset >= iov->iov_len)) { |
| offset -= iov->iov_len; |
| continue; |
| } |
| copy = min_t(unsigned int, iov->iov_len - offset, len); |
| if (copy_to_user(iov->iov_base + offset, kdata, copy)) |
| return -EFAULT; |
| offset = 0; |
| kdata += copy; |
| len -= copy; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Copy iovec to kernel. Returns -EFAULT on error. |
| * |
| * Note: this modifies the original iovec. |
| */ |
| |
| int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len) |
| { |
| while (len > 0) { |
| if (iov->iov_len) { |
| int copy = min_t(unsigned int, len, iov->iov_len); |
| if (copy_from_user(kdata, iov->iov_base, copy)) |
| return -EFAULT; |
| len -= copy; |
| kdata += copy; |
| iov->iov_base += copy; |
| iov->iov_len -= copy; |
| } |
| iov++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Copy iovec from kernel. Returns -EFAULT on error. |
| */ |
| |
| int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, |
| int offset, int len) |
| { |
| /* Skip over the finished iovecs */ |
| while (offset >= iov->iov_len) { |
| offset -= iov->iov_len; |
| iov++; |
| } |
| |
| while (len > 0) { |
| u8 __user *base = iov->iov_base + offset; |
| int copy = min_t(unsigned int, len, iov->iov_len - offset); |
| |
| offset = 0; |
| if (copy_from_user(kdata, base, copy)) |
| return -EFAULT; |
| len -= copy; |
| kdata += copy; |
| iov++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * And now for the all-in-one: copy and checksum from a user iovec |
| * directly to a datagram |
| * Calls to csum_partial but the last must be in 32 bit chunks |
| * |
| * ip_build_xmit must ensure that when fragmenting only the last |
| * call to this function will be unaligned also. |
| */ |
| int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov, |
| int offset, unsigned int len, __wsum *csump) |
| { |
| __wsum csum = *csump; |
| int partial_cnt = 0, err = 0; |
| |
| /* Skip over the finished iovecs */ |
| while (offset >= iov->iov_len) { |
| offset -= iov->iov_len; |
| iov++; |
| } |
| |
| while (len > 0) { |
| u8 __user *base = iov->iov_base + offset; |
| int copy = min_t(unsigned int, len, iov->iov_len - offset); |
| |
| offset = 0; |
| |
| /* There is a remnant from previous iov. */ |
| if (partial_cnt) { |
| int par_len = 4 - partial_cnt; |
| |
| /* iov component is too short ... */ |
| if (par_len > copy) { |
| if (copy_from_user(kdata, base, copy)) |
| goto out_fault; |
| kdata += copy; |
| base += copy; |
| partial_cnt += copy; |
| len -= copy; |
| iov++; |
| if (len) |
| continue; |
| *csump = csum_partial(kdata - partial_cnt, |
| partial_cnt, csum); |
| goto out; |
| } |
| if (copy_from_user(kdata, base, par_len)) |
| goto out_fault; |
| csum = csum_partial(kdata - partial_cnt, 4, csum); |
| kdata += par_len; |
| base += par_len; |
| copy -= par_len; |
| len -= par_len; |
| partial_cnt = 0; |
| } |
| |
| if (len > copy) { |
| partial_cnt = copy % 4; |
| if (partial_cnt) { |
| copy -= partial_cnt; |
| if (copy_from_user(kdata + copy, base + copy, |
| partial_cnt)) |
| goto out_fault; |
| } |
| } |
| |
| if (copy) { |
| csum = csum_and_copy_from_user(base, kdata, copy, |
| csum, &err); |
| if (err) |
| goto out; |
| } |
| len -= copy + partial_cnt; |
| kdata += copy + partial_cnt; |
| iov++; |
| } |
| *csump = csum; |
| out: |
| return err; |
| |
| out_fault: |
| err = -EFAULT; |
| goto out; |
| } |
| |
| EXPORT_SYMBOL(csum_partial_copy_fromiovecend); |
| EXPORT_SYMBOL(memcpy_fromiovec); |
| EXPORT_SYMBOL(memcpy_fromiovecend); |
| EXPORT_SYMBOL(memcpy_toiovec); |
| EXPORT_SYMBOL(memcpy_toiovecend); |