Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8c05dbf0 authored by John Fastabend's avatar John Fastabend Committed by Daniel Borkmann
Browse files

net: generalize sk_alloc_sg to work with scatterlist rings 



The current implementation of sk_alloc_sg expects scatterlist to always
start at entry 0 and complete at entry MAX_SKB_FRAGS.

Future patches will want to support starting at arbitrary offset into
scatterlist so add an additional sg_start parameters and then default
to the current values in TLS code paths.

Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 312fc2b4

include/net/sock.h

+1 −1
Original line number Diff line number Diff line
@@ -2142,7 +2142,7 @@ static inline struct page_frag *sk_page_frag(struct sock *sk) 
bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);



int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,

		int *sg_num_elem, unsigned int *sg_size,

		int sg_start, int *sg_curr, unsigned int *sg_size,

		int first_coalesce);



/*

net/core/sock.c

+16 −11
Original line number Diff line number Diff line
@@ -2240,19 +2240,20 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag) 
EXPORT_SYMBOL(sk_page_frag_refill);



int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,

		int *sg_num_elem, unsigned int *sg_size,

		int sg_start, int *sg_curr_index, unsigned int *sg_curr_size,

		int first_coalesce)

{

	int sg_curr = *sg_curr_index, use = 0, rc = 0;

	unsigned int size = *sg_curr_size;

	struct page_frag *pfrag;

	unsigned int size = *sg_size;

	int num_elem = *sg_num_elem, use = 0, rc = 0;

	struct scatterlist *sge;

	unsigned int orig_offset;



	len -= size;

	pfrag = sk_page_frag(sk);



	while (len > 0) {

		unsigned int orig_offset;



		if (!sk_page_frag_refill(sk, pfrag)) {

			rc = -ENOMEM;

			goto out;
@@ -2270,17 +2271,21 @@ int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, 
		orig_offset = pfrag->offset;

		pfrag->offset += use;



		sge = sg + num_elem - 1;

		if (num_elem > first_coalesce && sg_page(sg) == pfrag->page &&

		sge = sg + sg_curr - 1;

		if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page &&

		    sg->offset + sg->length == orig_offset) {

			sg->length += use;

		} else {

			sge++;

			sge = sg + sg_curr;

			sg_unmark_end(sge);

			sg_set_page(sge, pfrag->page, use, orig_offset);

			get_page(pfrag->page);

			++num_elem;

			if (num_elem == MAX_SKB_FRAGS) {

			sg_curr++;



			if (sg_curr == MAX_SKB_FRAGS)

				sg_curr = 0;



			if (sg_curr == sg_start) {

				rc = -ENOSPC;

				break;

			}
@@ -2289,8 +2294,8 @@ int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, 
		len -= use;

	}

out:

	*sg_size = size;

	*sg_num_elem = num_elem;

	*sg_curr_size = size;

	*sg_curr_index = sg_curr;

	return rc;

}

EXPORT_SYMBOL(sk_alloc_sg);

net/tls/tls_sw.c

+2 −2
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static int alloc_encrypted_sg(struct sock *sk, int len) 
	int rc = 0;



	rc = sk_alloc_sg(sk, len,

			 ctx->sg_encrypted_data,

			 ctx->sg_encrypted_data, 0,

			 &ctx->sg_encrypted_num_elem,

			 &ctx->sg_encrypted_size, 0);
@@ -107,7 +107,7 @@ static int alloc_plaintext_sg(struct sock *sk, int len) 
	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);

	int rc = 0;



	rc = sk_alloc_sg(sk, len, ctx->sg_plaintext_data,

	rc = sk_alloc_sg(sk, len, ctx->sg_plaintext_data, 0,

			 &ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,

			 tls_ctx->pending_open_record_frags);