diff options
| -rw-r--r-- | include/linux/net.h | 3 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 6 | ||||
| -rw-r--r-- | include/net/tcp.h | 3 | ||||
| -rw-r--r-- | net/core/skbuff.c | 246 | ||||
| -rw-r--r-- | net/ipv4/af_inet.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 129 | ||||
| -rw-r--r-- | net/socket.c | 13 |
7 files changed, 401 insertions, 0 deletions
diff --git a/include/linux/net.h b/include/linux/net.h index 596131ea46f4..0235d917d5c3 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -22,6 +22,7 @@ #include <asm/socket.h> struct poll_table_struct; +struct pipe_inode_info; struct inode; struct net; @@ -172,6 +173,8 @@ struct proto_ops { struct vm_area_struct * vma); ssize_t (*sendpage) (struct socket *sock, struct page *page, int offset, size_t size, int flags); + ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, unsigned int flags); }; struct net_proto_family { diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index bddd50bd6878..d39f53ef66bb 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -95,6 +95,7 @@ struct net_device; struct scatterlist; +struct pipe_inode_info; #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) struct nf_conntrack { @@ -1559,6 +1560,11 @@ extern int skb_store_bits(struct sk_buff *skb, int offset, extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, int len, __wsum csum); +extern int skb_splice_bits(struct sk_buff *skb, + unsigned int offset, + struct pipe_inode_info *pipe, + unsigned int len, + unsigned int flags); extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); extern void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); diff --git a/include/net/tcp.h b/include/net/tcp.h index cb5b033e0e59..d893b4480769 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -309,6 +309,9 @@ extern int tcp_twsk_unique(struct sock *sk, extern void tcp_twsk_destructor(struct sock *sk); +extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, unsigned int flags); + static inline void tcp_dec_quickack_mode(struct sock *sk, const unsigned int pkts) { diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b6283779e93d..98420f9c4b6d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -52,6 +52,7 @@ #endif #include <linux/string.h> #include <linux/skbuff.h> +#include <linux/splice.h> #include <linux/cache.h> #include <linux/rtnetlink.h> #include <linux/init.h> @@ -71,6 +72,40 @@ static struct kmem_cache *skbuff_head_cache __read_mostly; static struct kmem_cache *skbuff_fclone_cache __read_mostly; +static void sock_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + struct sk_buff *skb = (struct sk_buff *) buf->private; + + kfree_skb(skb); +} + +static void sock_pipe_buf_get(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + struct sk_buff *skb = (struct sk_buff *) buf->private; + + skb_get(skb); +} + +static int sock_pipe_buf_steal(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + return 1; +} + + +/* Pipe buffer operations for a socket. */ +static struct pipe_buf_operations sock_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = sock_pipe_buf_release, + .steal = sock_pipe_buf_steal, + .get = sock_pipe_buf_get, +}; + /* * Keep out-of-line to prevent kernel bloat. * __builtin_return_address is not used because it is not always @@ -1122,6 +1157,217 @@ fault: return -EFAULT; } +/* + * Callback from splice_to_pipe(), if we need to release some pages + * at the end of the spd in case we error'ed out in filling the pipe. + */ +static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i) +{ + struct sk_buff *skb = (struct sk_buff *) spd->partial[i].private; + + kfree_skb(skb); +} + +/* + * Fill page/offset/length into spd, if it can hold more pages. + */ +static inline int spd_fill_page(struct splice_pipe_desc *spd, struct page *page, + unsigned int len, unsigned int offset, + struct sk_buff *skb) +{ + if (unlikely(spd->nr_pages == PIPE_BUFFERS)) + return 1; + + spd->pages[spd->nr_pages] = page; + spd->partial[spd->nr_pages].len = len; + spd->partial[spd->nr_pages].offset = offset; + spd->partial[spd->nr_pages].private = (unsigned long) skb_get(skb); + spd->nr_pages++; + return 0; +} + +/* + * Map linear and fragment data from the skb to spd. Returns number of + * pages mapped. + */ +static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset, + unsigned int *total_len, + struct splice_pipe_desc *spd) +{ + unsigned int nr_pages = spd->nr_pages; + unsigned int poff, plen, len, toff, tlen; + int headlen, seg; + + toff = *offset; + tlen = *total_len; + if (!tlen) + goto err; + + /* + * if the offset is greater than the linear part, go directly to + * the fragments. + */ + headlen = skb_headlen(skb); + if (toff >= headlen) { + toff -= headlen; + goto map_frag; + } + + /* + * first map the linear region into the pages/partial map, skipping + * any potential initial offset. + */ + len = 0; + while (len < headlen) { + void *p = skb->data + len; + + poff = (unsigned long) p & (PAGE_SIZE - 1); + plen = min_t(unsigned int, headlen - len, PAGE_SIZE - poff); + len += plen; + + if (toff) { + if (plen <= toff) { + toff -= plen; + continue; + } + plen -= toff; + poff += toff; + toff = 0; + } + + plen = min(plen, tlen); + if (!plen) + break; + + /* + * just jump directly to update and return, no point + * in going over fragments when the output is full. + */ + if (spd_fill_page(spd, virt_to_page(p), plen, poff, skb)) + goto done; + + tlen -= plen; + } + + /* + * then map the fragments + */ +map_frag: + for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { + const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; + + plen = f->size; + poff = f->page_offset; + + if (toff) { + if (plen <= toff) { + toff -= plen; + continue; + } + plen -= toff; + poff += toff; + toff = 0; + } + + plen = min(plen, tlen); + if (!plen) + break; + + if (spd_fill_page(spd, f->page, plen, poff, skb)) + break; + + tlen -= plen; + } + +done: + if (spd->nr_pages - nr_pages) { + *offset = 0; + *total_len = tlen; + return 0; + } +err: + return 1; +} + +/* + * Map data from the skb to a pipe. Should handle both the linear part, + * the fragments, and the frag list. It does NOT handle frag lists within + * the frag list, if such a thing exists. We'd probably need to recurse to + * handle that cleanly. + */ +int skb_splice_bits(struct sk_buff *__skb, unsigned int offset, + struct pipe_inode_info *pipe, unsigned int tlen, + unsigned int flags) +{ + struct partial_page partial[PIPE_BUFFERS]; + struct page *pages[PIPE_BUFFERS]; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &sock_pipe_buf_ops, + .spd_release = sock_spd_release, + }; + struct sk_buff *skb; + + /* + * I'd love to avoid the clone here, but tcp_read_sock() + * ignores reference counts and unconditonally kills the sk_buff + * on return from the actor. + */ + skb = skb_clone(__skb, GFP_KERNEL); + if (unlikely(!skb)) + return -ENOMEM; + + /* + * __skb_splice_bits() only fails if the output has no room left, + * so no point in going over the frag_list for the error case. + */ + if (__skb_splice_bits(skb, &offset, &tlen, &spd)) + goto done; + else if (!tlen) + goto done; + + /* + * now see if we have a frag_list to map + */ + if (skb_shinfo(skb)->frag_list) { + struct sk_buff *list = skb_shinfo(skb)->frag_list; + + for (; list && tlen; list = list->next) { + if (__skb_splice_bits(list, &offset, &tlen, &spd)) + break; + } + } + +done: + /* + * drop our reference to the clone, the pipe consumption will + * drop the rest. + */ + kfree_skb(skb); + + if (spd.nr_pages) { + int ret; + + /* + * Drop the socket lock, otherwise we have reverse + * locking dependencies between sk_lock and i_mutex + * here as compared to sendfile(). We enter here + * with the socket lock held, and splice_to_pipe() will + * grab the pipe inode lock. For sendfile() emulation, + * we call into ->sendpage() with the i_mutex lock held + * and networking will grab the socket lock. + */ + release_sock(__skb->sk); + ret = splice_to_pipe(pipe, &spd); + lock_sock(__skb->sk); + return ret; + } + + return 0; +} + /** * skb_store_bits - store bits from kernel buffer to skb * @skb: destination buffer diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index d2f22e74b267..c75f20b49935 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -838,6 +838,7 @@ const struct proto_ops inet_stream_ops = { .recvmsg = sock_common_recvmsg, .mmap = sock_no_mmap, .sendpage = tcp_sendpage, + .splice_read = tcp_splice_read, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_sock_common_setsockopt, .compat_getsockopt = compat_sock_common_getsockopt, diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8e65182f7af1..56ed40703f98 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -254,6 +254,10 @@ #include <linux/poll.h> #include <linux/init.h> #include <linux/fs.h> +#include <linux/skbuff.h> +#include <linux/splice.h> +#include <linux/net.h> +#include <linux/socket.h> #include <linux/random.h> #include <linux/bootmem.h> #include <linux/cache.h> @@ -265,6 +269,7 @@ #include <net/xfrm.h> #include <net/ip.h> #include <net/netdma.h> +#include <net/sock.h> #include <asm/uaccess.h> #include <asm/ioctls.h> @@ -292,6 +297,15 @@ EXPORT_SYMBOL(tcp_memory_allocated); EXPORT_SYMBOL(tcp_sockets_allocated); /* + * TCP splice context + */ +struct tcp_splice_state { + struct pipe_inode_info *pipe; + size_t len; + unsigned int flags; +}; + +/* * Pressure flag: try to collapse. * Technical note: it is used by multiple contexts non atomically. * All the sk_stream_mem_schedule() is of this nature: accounting @@ -501,6 +515,120 @@ static inline void tcp_push(struct sock *sk, int flags, int mss_now, } } +int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + struct tcp_splice_state *tss = rd_desc->arg.data; + + return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags); +} + +static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) +{ + /* Store TCP splice context information in read_descriptor_t. */ + read_descriptor_t rd_desc = { + .arg.data = tss, + }; + + return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); +} + +/** + * tcp_splice_read - splice data from TCP socket to a pipe + * @sock: socket to splice from + * @ppos: position (not valid) + * @pipe: pipe to splice to + * @len: number of bytes to splice + * @flags: splice modifier flags + * + * Description: + * Will read pages from given socket and fill them into a pipe. + * + **/ +ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + struct sock *sk = sock->sk; + struct tcp_splice_state tss = { + .pipe = pipe, + .len = len, + .flags = flags, + }; + long timeo; + ssize_t spliced; + int ret; + + /* + * We can't seek on a socket input + */ + if (unlikely(*ppos)) + return -ESPIPE; + + ret = spliced = 0; + + lock_sock(sk); + + timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK); + while (tss.len) { + ret = __tcp_splice_read(sk, &tss); + if (ret < 0) + break; + else if (!ret) { + if (spliced) + break; + if (flags & SPLICE_F_NONBLOCK) { + ret = -EAGAIN; + break; + } + if (sock_flag(sk, SOCK_DONE)) + break; + if (sk->sk_err) { + ret = sock_error(sk); + break; + } + if (sk->sk_shutdown & RCV_SHUTDOWN) + break; + if (sk->sk_state == TCP_CLOSE) { + /* + * This occurs when user tries to read + * from never connected socket. + */ + if (!sock_flag(sk, SOCK_DONE)) + ret = -ENOTCONN; + break; + } + if (!timeo) { + ret = -EAGAIN; + break; + } + sk_wait_data(sk, &timeo); + if (signal_pending(current)) { + ret = sock_intr_errno(timeo); + break; + } + continue; + } + tss.len -= ret; + spliced += ret; + + release_sock(sk); + lock_sock(sk); + + if (sk->sk_err || sk->sk_state == TCP_CLOSE || + (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo || + signal_pending(current)) + break; + } + + release_sock(sk); + + if (spliced) + return spliced; + + return ret; +} + static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, size_t psize, int flags) { @@ -2532,6 +2660,7 @@ EXPORT_SYMBOL(tcp_poll); EXPORT_SYMBOL(tcp_read_sock); EXPORT_SYMBOL(tcp_recvmsg); EXPORT_SYMBOL(tcp_sendmsg); +EXPORT_SYMBOL(tcp_splice_read); EXPORT_SYMBOL(tcp_sendpage); EXPORT_SYMBOL(tcp_setsockopt); EXPORT_SYMBOL(tcp_shutdown); diff --git a/net/socket.c b/net/socket.c index 74784dfe8e5b..92fab9e1c602 100644 --- a/net/socket.c +++ b/net/socket.c @@ -112,6 +112,9 @@ static long compat_sock_ioctl(struct file *file, static int sock_fasync(int fd, struct file *filp, int on); static ssize_t sock_sendpage(struct file *file, struct page *page, int offset, size_t size, loff_t *ppos, int more); +static ssize_t sock_splice_read(struct file *file, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags); /* * Socket files have a set of 'special' operations as well as the generic file ones. These don't appear @@ -134,6 +137,7 @@ static const struct file_operations socket_file_ops = { .fasync = sock_fasync, .sendpage = sock_sendpage, .splice_write = generic_splice_sendpage, + .splice_read = sock_splice_read, }; /* @@ -691,6 +695,15 @@ static ssize_t sock_sendpage(struct file *file, struct page *page, return sock->ops->sendpage(sock, page, offset, size, flags); } +static ssize_t sock_splice_read(struct file *file, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + struct socket *sock = file->private_data; + + return sock->ops->splice_read(sock, ppos, pipe, len, flags); +} + static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb, struct sock_iocb *siocb) { |