diff options
| -rw-r--r-- | include/linux/skbuff.h | 5 | ||||
| -rw-r--r-- | include/linux/socket.h | 2 | ||||
| -rw-r--r-- | net/core/datagram.c | 92 | ||||
| -rw-r--r-- | net/core/iovec.c | 26 |
4 files changed, 125 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5fd389162f0..af2b21bdda8 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1717,6 +1717,11 @@ extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, struct iovec *from, int len); +extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, + int offset, + const struct iovec *to, + int to_offset, + int size); extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); diff --git a/include/linux/socket.h b/include/linux/socket.h index 421afb4d29b..171b08db9c4 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -318,6 +318,8 @@ extern int csum_partial_copy_fromiovecend(unsigned char *kdata, extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode); extern int memcpy_toiovec(struct iovec *v, unsigned char *kdata, int len); +extern int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata, + int offset, int len); extern int move_addr_to_user(struct sockaddr *kaddr, int klen, void __user *uaddr, int __user *ulen); extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr *kaddr); extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data); diff --git a/net/core/datagram.c b/net/core/datagram.c index d0de644b378..4dbb05cd572 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -339,6 +339,98 @@ fault: } /** + * skb_copy_datagram_const_iovec - Copy a datagram to an iovec. + * @skb: buffer to copy + * @offset: offset in the buffer to start copying from + * @to: io vector to copy to + * @to_offset: offset in the io vector to start copying to + * @len: amount of data to copy from buffer to iovec + * + * Returns 0 or -EFAULT. + * Note: the iovec is not modified during the copy. + */ +int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset, + const struct iovec *to, int to_offset, + int len) +{ + int start = skb_headlen(skb); + int i, copy = start - offset; + + /* Copy header. */ + if (copy > 0) { + if (copy > len) + copy = len; + if (memcpy_toiovecend(to, skb->data + offset, to_offset, copy)) + goto fault; + if ((len -= copy) == 0) + return 0; + offset += copy; + to_offset += copy; + } + + /* Copy paged appendix. Hmm... why does this look so complicated? */ + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + int end; + + WARN_ON(start > offset + len); + + end = start + skb_shinfo(skb)->frags[i].size; + if ((copy = end - offset) > 0) { + int err; + u8 *vaddr; + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + struct page *page = frag->page; + + if (copy > len) + copy = len; + vaddr = kmap(page); + err = memcpy_toiovecend(to, vaddr + frag->page_offset + + offset - start, to_offset, copy); + kunmap(page); + if (err) + goto fault; + if (!(len -= copy)) + return 0; + offset += copy; + to_offset += copy; + } + start = end; + } + + if (skb_shinfo(skb)->frag_list) { + struct sk_buff *list = skb_shinfo(skb)->frag_list; + + for (; list; list = list->next) { + int end; + + WARN_ON(start > offset + len); + + end = start + list->len; + if ((copy = end - offset) > 0) { + if (copy > len) + copy = len; + if (skb_copy_datagram_const_iovec(list, + offset - start, + to, to_offset, + copy)) + goto fault; + if ((len -= copy) == 0) + return 0; + offset += copy; + to_offset += copy; + } + start = end; + } + } + if (!len) + return 0; + +fault: + return -EFAULT; +} +EXPORT_SYMBOL(skb_copy_datagram_const_iovec); + +/** * skb_copy_datagram_from_iovec - Copy a datagram from an iovec. * @skb: buffer to copy * @offset: offset in the buffer to start copying to diff --git a/net/core/iovec.c b/net/core/iovec.c index 4c9c0121c9d..a215545c0a3 100644 --- a/net/core/iovec.c +++ b/net/core/iovec.c @@ -98,6 +98,31 @@ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) } /* + * 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); + offset = 0; + if (copy_to_user(iov->iov_base, kdata, copy)) + return -EFAULT; + kdata += copy; + len -= copy; + } + + return 0; +} + +/* * Copy iovec to kernel. Returns -EFAULT on error. * * Note: this modifies the original iovec. @@ -236,3 +261,4 @@ EXPORT_SYMBOL(csum_partial_copy_fromiovecend); EXPORT_SYMBOL(memcpy_fromiovec); EXPORT_SYMBOL(memcpy_fromiovecend); EXPORT_SYMBOL(memcpy_toiovec); +EXPORT_SYMBOL(memcpy_toiovecend); |