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-rw-r--r--include/uapi/linux/tcp.h8
-rw-r--r--net/ipv4/af_inet.c2
-rw-r--r--net/ipv4/tcp.c194
-rw-r--r--net/ipv6/af_inet6.c2
4 files changed, 116 insertions, 90 deletions
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 379b08700a54..e9e8373b34b9 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -122,6 +122,7 @@ enum {
#define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */
#define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */
#define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */
+#define TCP_ZEROCOPY_RECEIVE 35
struct tcp_repair_opt {
__u32 opt_code;
@@ -276,4 +277,11 @@ struct tcp_diag_md5sig {
__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN];
};
+/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
+
+struct tcp_zerocopy_receive {
+ __u64 address; /* in: address of mapping */
+ __u32 length; /* in/out: number of bytes to map/mapped */
+ __u32 recv_skip_hint; /* out: amount of bytes to skip */
+};
#endif /* _UAPI_LINUX_TCP_H */
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 3ebf599cebae..b403499fdabe 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -994,7 +994,9 @@ const struct proto_ops inet_stream_ops = {
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.recvmsg = inet_recvmsg,
+#ifdef CONFIG_MMU
.mmap = tcp_mmap,
+#endif
.sendpage = inet_sendpage,
.splice_read = tcp_splice_read,
.read_sock = tcp_read_sock,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index dfd090ea54ad..4028ddd14dd5 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1726,118 +1726,113 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
}
EXPORT_SYMBOL(tcp_set_rcvlowat);
-/* When user wants to mmap X pages, we first need to perform the mapping
- * before freeing any skbs in receive queue, otherwise user would be unable
- * to fallback to standard recvmsg(). This happens if some data in the
- * requested block is not exactly fitting in a page.
- *
- * We only support order-0 pages for the moment.
- * mmap() on TCP is very strict, there is no point
- * trying to accommodate with pathological layouts.
- */
+#ifdef CONFIG_MMU
+static const struct vm_operations_struct tcp_vm_ops = {
+};
+
int tcp_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma)
{
- unsigned long size = vma->vm_end - vma->vm_start;
- unsigned int nr_pages = size >> PAGE_SHIFT;
- struct page **pages_array = NULL;
- u32 seq, len, offset, nr = 0;
- struct sock *sk = sock->sk;
- const skb_frag_t *frags;
+ if (vma->vm_flags & (VM_WRITE | VM_EXEC))
+ return -EPERM;
+ vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
+
+ /* Instruct vm_insert_page() to not down_read(mmap_sem) */
+ vma->vm_flags |= VM_MIXEDMAP;
+
+ vma->vm_ops = &tcp_vm_ops;
+ return 0;
+}
+EXPORT_SYMBOL(tcp_mmap);
+
+static int tcp_zerocopy_receive(struct sock *sk,
+ struct tcp_zerocopy_receive *zc)
+{
+ unsigned long address = (unsigned long)zc->address;
+ const skb_frag_t *frags = NULL;
+ u32 length = 0, seq, offset;
+ struct vm_area_struct *vma;
+ struct sk_buff *skb = NULL;
struct tcp_sock *tp;
- struct sk_buff *skb;
int ret;
- if (vma->vm_pgoff || !nr_pages)
+ if (address & (PAGE_SIZE - 1) || address != zc->address)
return -EINVAL;
- if (vma->vm_flags & VM_WRITE)
- return -EPERM;
- /* TODO: Maybe the following is not needed if pages are COW */
- vma->vm_flags &= ~VM_MAYWRITE;
-
- lock_sock(sk);
-
- ret = -ENOTCONN;
if (sk->sk_state == TCP_LISTEN)
- goto out;
+ return -ENOTCONN;
sock_rps_record_flow(sk);
- if (tcp_inq(sk) < size) {
- ret = sock_flag(sk, SOCK_DONE) ? -EIO : -EAGAIN;
+ down_read(&current->mm->mmap_sem);
+
+ ret = -EINVAL;
+ vma = find_vma(current->mm, address);
+ if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops)
goto out;
- }
+ zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);
+
tp = tcp_sk(sk);
seq = tp->copied_seq;
- /* Abort if urgent data is in the area */
- if (unlikely(tp->urg_data)) {
- u32 urg_offset = tp->urg_seq - seq;
+ zc->length = min_t(u32, zc->length, tcp_inq(sk));
+ zc->length &= ~(PAGE_SIZE - 1);
- ret = -EINVAL;
- if (urg_offset < size)
- goto out;
- }
- ret = -ENOMEM;
- pages_array = kvmalloc_array(nr_pages, sizeof(struct page *),
- GFP_KERNEL);
- if (!pages_array)
- goto out;
- skb = tcp_recv_skb(sk, seq, &offset);
- ret = -EINVAL;
-skb_start:
- /* We do not support anything not in page frags */
- offset -= skb_headlen(skb);
- if ((int)offset < 0)
- goto out;
- if (skb_has_frag_list(skb))
- goto out;
- len = skb->data_len - offset;
- frags = skb_shinfo(skb)->frags;
- while (offset) {
- if (frags->size > offset)
- goto out;
- offset -= frags->size;
- frags++;
- }
- while (nr < nr_pages) {
- if (len) {
- if (len < PAGE_SIZE)
- goto out;
- if (frags->size != PAGE_SIZE || frags->page_offset)
- goto out;
- pages_array[nr++] = skb_frag_page(frags);
- frags++;
- len -= PAGE_SIZE;
- seq += PAGE_SIZE;
- continue;
+ zap_page_range(vma, address, zc->length);
+
+ zc->recv_skip_hint = 0;
+ ret = 0;
+ while (length + PAGE_SIZE <= zc->length) {
+ if (zc->recv_skip_hint < PAGE_SIZE) {
+ if (skb) {
+ skb = skb->next;
+ offset = seq - TCP_SKB_CB(skb)->seq;
+ } else {
+ skb = tcp_recv_skb(sk, seq, &offset);
+ }
+
+ zc->recv_skip_hint = skb->len - offset;
+ offset -= skb_headlen(skb);
+ if ((int)offset < 0 || skb_has_frag_list(skb))
+ break;
+ frags = skb_shinfo(skb)->frags;
+ while (offset) {
+ if (frags->size > offset)
+ goto out;
+ offset -= frags->size;
+ frags++;
+ }
}
- skb = skb->next;
- offset = seq - TCP_SKB_CB(skb)->seq;
- goto skb_start;
- }
- /* OK, we have a full set of pages ready to be inserted into vma */
- for (nr = 0; nr < nr_pages; nr++) {
- ret = vm_insert_page(vma, vma->vm_start + (nr << PAGE_SHIFT),
- pages_array[nr]);
+ if (frags->size != PAGE_SIZE || frags->page_offset)
+ break;
+ ret = vm_insert_page(vma, address + length,
+ skb_frag_page(frags));
if (ret)
- goto out;
+ break;
+ length += PAGE_SIZE;
+ seq += PAGE_SIZE;
+ zc->recv_skip_hint -= PAGE_SIZE;
+ frags++;
}
- /* operation is complete, we can 'consume' all skbs */
- tp->copied_seq = seq;
- tcp_rcv_space_adjust(sk);
-
- /* Clean up data we have read: This will do ACK frames. */
- tcp_recv_skb(sk, seq, &offset);
- tcp_cleanup_rbuf(sk, size);
-
- ret = 0;
out:
- release_sock(sk);
- kvfree(pages_array);
+ up_read(&current->mm->mmap_sem);
+ if (length) {
+ tp->copied_seq = seq;
+ tcp_rcv_space_adjust(sk);
+
+ /* Clean up data we have read: This will do ACK frames. */
+ tcp_recv_skb(sk, seq, &offset);
+ tcp_cleanup_rbuf(sk, length);
+ ret = 0;
+ if (length == zc->length)
+ zc->recv_skip_hint = 0;
+ } else {
+ if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE))
+ ret = -EIO;
+ }
+ zc->length = length;
return ret;
}
-EXPORT_SYMBOL(tcp_mmap);
+#endif
static void tcp_update_recv_tstamps(struct sk_buff *skb,
struct scm_timestamping *tss)
@@ -3472,6 +3467,25 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
}
return 0;
}
+#ifdef CONFIG_MMU
+ case TCP_ZEROCOPY_RECEIVE: {
+ struct tcp_zerocopy_receive zc;
+ int err;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+ if (len != sizeof(zc))
+ return -EINVAL;
+ if (copy_from_user(&zc, optval, len))
+ return -EFAULT;
+ lock_sock(sk);
+ err = tcp_zerocopy_receive(sk, &zc);
+ release_sock(sk);
+ if (!err && copy_to_user(optval, &zc, len))
+ err = -EFAULT;
+ return err;
+ }
+#endif
default:
return -ENOPROTOOPT;
}
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 36d622c477b1..d0af96e0d109 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -578,7 +578,9 @@ const struct proto_ops inet6_stream_ops = {
.getsockopt = sock_common_getsockopt, /* ok */
.sendmsg = inet_sendmsg, /* ok */
.recvmsg = inet_recvmsg, /* ok */
+#ifdef CONFIG_MMU
.mmap = tcp_mmap,
+#endif
.sendpage = inet_sendpage,
.sendmsg_locked = tcp_sendmsg_locked,
.sendpage_locked = tcp_sendpage_locked,
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 16:37:18 +0300