cregit-Linux how code gets into the kernel

Release 4.15 net/dsa/tag_dsa.c

Directory: net/dsa
/*
 * net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging
 * Copyright (c) 2008-2009 Marvell Semiconductor
 *
 * 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.
 */

#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/slab.h>

#include "dsa_priv.h"


#define DSA_HLEN	4


static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); u8 *dsa_header; /* * Convert the outermost 802.1q tag to a DSA tag for tagged * packets, or insert a DSA tag between the addresses and * the ethertype field for untagged packets. */ if (skb->protocol == htons(ETH_P_8021Q)) { if (skb_cow_head(skb, 0) < 0) return NULL; /* * Construct tagged FROM_CPU DSA tag from 802.1q tag. */ dsa_header = skb->data + 2 * ETH_ALEN; dsa_header[0] = 0x60 | dp->ds->index; dsa_header[1] = dp->index << 3; /* * Move CFI field from byte 2 to byte 1. */ if (dsa_header[2] & 0x10) { dsa_header[1] |= 0x01; dsa_header[2] &= ~0x10; } } else { if (skb_cow_head(skb, DSA_HLEN) < 0) return NULL; skb_push(skb, DSA_HLEN); memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); /* * Construct untagged FROM_CPU DSA tag. */ dsa_header = skb->data + 2 * ETH_ALEN; dsa_header[0] = 0x40 | dp->ds->index; dsa_header[1] = dp->index << 3; dsa_header[2] = 0x00; dsa_header[3] = 0x00; } return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Lennert Buytenhek18987.91%228.57%
Vivien Didelot219.77%342.86%
Florian Fainelli52.33%228.57%
Total215100.00%7100.00%


static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) { u8 *dsa_header; int source_device; int source_port; if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) return NULL; /* * The ethertype field is part of the DSA header. */ dsa_header = skb->data - 2; /* * Check that frame type is either TO_CPU or FORWARD. */ if ((dsa_header[0] & 0xc0) != 0x00 && (dsa_header[0] & 0xc0) != 0xc0) return NULL; /* * Determine source device and port. */ source_device = dsa_header[0] & 0x1f; source_port = (dsa_header[1] >> 3) & 0x1f; skb->dev = dsa_master_find_slave(dev, source_device, source_port); if (!skb->dev) return NULL; /* * Convert the DSA header to an 802.1q header if the 'tagged' * bit in the DSA header is set. If the 'tagged' bit is clear, * delete the DSA header entirely. */ if (dsa_header[0] & 0x20) { u8 new_header[4]; /* * Insert 802.1q ethertype and copy the VLAN-related * fields, but clear the bit that will hold CFI (since * DSA uses that bit location for another purpose). */ new_header[0] = (ETH_P_8021Q >> 8) & 0xff; new_header[1] = ETH_P_8021Q & 0xff; new_header[2] = dsa_header[2] & ~0x10; new_header[3] = dsa_header[3]; /* * Move CFI bit from its place in the DSA header to * its 802.1q-designated place. */ if (dsa_header[1] & 0x01) new_header[2] |= 0x10; /* * Update packet checksum if skb is CHECKSUM_COMPLETE. */ if (skb->ip_summed == CHECKSUM_COMPLETE) { __wsum c = skb->csum; c = csum_add(c, csum_partial(new_header + 2, 2, 0)); c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0)); skb->csum = c; } memcpy(dsa_header, new_header, DSA_HLEN); } else { /* * Remove DSA tag and update checksum. */ skb_pull_rcsum(skb, DSA_HLEN); memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - DSA_HLEN, 2 * ETH_ALEN); } skb->offload_fwd_mark = 1; return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Lennert Buytenhek29190.09%225.00%
Vivien Didelot216.50%337.50%
Andrew Lunn72.17%225.00%
Florian Fainelli41.24%112.50%
Total323100.00%8100.00%

const struct dsa_device_ops dsa_netdev_ops = { .xmit = dsa_xmit, .rcv = dsa_rcv, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Lennert Buytenhek50588.29%214.29%
Vivien Didelot427.34%642.86%
Florian Fainelli152.62%321.43%
Andrew Lunn71.22%214.29%
Tejun Heo30.52%17.14%
Total572100.00%14100.00%
Directory: net/dsa
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