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94f633ea8a
af_packet fanout uses RCU rules to ensure f->arr elements
are not dismantled before RCU grace period.
However, it lacks rcu accessors to make sure KCSAN and other tools
wont detect data races. Stupid compilers could also play games.
Fixes: dc99f60069 ("packet: Add fanout support.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __PACKET_INTERNAL_H__
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#define __PACKET_INTERNAL_H__
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#include <linux/refcount.h>
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struct packet_mclist {
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struct packet_mclist *next;
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int ifindex;
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int count;
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unsigned short type;
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unsigned short alen;
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unsigned char addr[MAX_ADDR_LEN];
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};
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/* kbdq - kernel block descriptor queue */
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struct tpacket_kbdq_core {
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struct pgv *pkbdq;
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unsigned int feature_req_word;
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unsigned int hdrlen;
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unsigned char reset_pending_on_curr_blk;
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unsigned char delete_blk_timer;
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unsigned short kactive_blk_num;
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unsigned short blk_sizeof_priv;
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/* last_kactive_blk_num:
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* trick to see if user-space has caught up
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* in order to avoid refreshing timer when every single pkt arrives.
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*/
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unsigned short last_kactive_blk_num;
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char *pkblk_start;
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char *pkblk_end;
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int kblk_size;
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unsigned int max_frame_len;
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unsigned int knum_blocks;
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uint64_t knxt_seq_num;
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char *prev;
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char *nxt_offset;
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struct sk_buff *skb;
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rwlock_t blk_fill_in_prog_lock;
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/* Default is set to 8ms */
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#define DEFAULT_PRB_RETIRE_TOV (8)
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unsigned short retire_blk_tov;
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unsigned short version;
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unsigned long tov_in_jiffies;
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/* timer to retire an outstanding block */
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struct timer_list retire_blk_timer;
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};
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struct pgv {
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char *buffer;
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};
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struct packet_ring_buffer {
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struct pgv *pg_vec;
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unsigned int head;
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unsigned int frames_per_block;
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unsigned int frame_size;
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unsigned int frame_max;
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unsigned int pg_vec_order;
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unsigned int pg_vec_pages;
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unsigned int pg_vec_len;
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unsigned int __percpu *pending_refcnt;
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union {
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unsigned long *rx_owner_map;
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struct tpacket_kbdq_core prb_bdqc;
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};
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};
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extern struct mutex fanout_mutex;
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#define PACKET_FANOUT_MAX (1 << 16)
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struct packet_fanout {
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possible_net_t net;
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unsigned int num_members;
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u32 max_num_members;
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u16 id;
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u8 type;
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u8 flags;
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union {
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atomic_t rr_cur;
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struct bpf_prog __rcu *bpf_prog;
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};
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struct list_head list;
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spinlock_t lock;
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refcount_t sk_ref;
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struct packet_type prot_hook ____cacheline_aligned_in_smp;
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struct sock __rcu *arr[];
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};
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struct packet_rollover {
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int sock;
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atomic_long_t num;
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atomic_long_t num_huge;
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atomic_long_t num_failed;
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#define ROLLOVER_HLEN (L1_CACHE_BYTES / sizeof(u32))
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u32 history[ROLLOVER_HLEN] ____cacheline_aligned;
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} ____cacheline_aligned_in_smp;
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struct packet_sock {
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/* struct sock has to be the first member of packet_sock */
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struct sock sk;
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struct packet_fanout *fanout;
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union tpacket_stats_u stats;
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struct packet_ring_buffer rx_ring;
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struct packet_ring_buffer tx_ring;
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int copy_thresh;
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spinlock_t bind_lock;
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struct mutex pg_vec_lock;
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unsigned int running; /* bind_lock must be held */
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unsigned int auxdata:1, /* writer must hold sock lock */
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origdev:1,
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has_vnet_hdr:1,
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tp_loss:1,
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tp_tx_has_off:1;
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int pressure;
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int ifindex; /* bound device */
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__be16 num;
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struct packet_rollover *rollover;
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struct packet_mclist *mclist;
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atomic_t mapped;
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enum tpacket_versions tp_version;
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unsigned int tp_hdrlen;
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unsigned int tp_reserve;
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unsigned int tp_tstamp;
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struct completion skb_completion;
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struct net_device __rcu *cached_dev;
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int (*xmit)(struct sk_buff *skb);
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struct packet_type prot_hook ____cacheline_aligned_in_smp;
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atomic_t tp_drops ____cacheline_aligned_in_smp;
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};
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static inline struct packet_sock *pkt_sk(struct sock *sk)
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{
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return (struct packet_sock *)sk;
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}
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#endif
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