diff options
| -rw-r--r-- | net/packet/af_packet.c | 937 |
1 files changed, 891 insertions, 46 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index c698cec..4371e3a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -40,6 +40,10 @@ * byte arrays at the end of sockaddr_ll * and packet_mreq. * Johann Baudy : Added TX RING. + * Chetan Loke : Implemented TPACKET_V3 block abstraction + * layer. + * Copyright (C) 2011, <lokec@ccs.neu.edu> + * * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -161,9 +165,56 @@ struct packet_mreq_max { unsigned char mr_address[MAX_ADDR_LEN]; }; -static int packet_set_ring(struct sock *sk, struct tpacket_req *req, +static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, int closing, int tx_ring); + +#define V3_ALIGNMENT (8) + +#define BLK_HDR_LEN (ALIGN(sizeof(struct block_desc), V3_ALIGNMENT)) + +#define BLK_PLUS_PRIV(sz_of_priv) \ + (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) + +/* kbdq - kernel block descriptor queue */ +struct kbdq_core { + struct pgv *pkbdq; + unsigned int feature_req_word; + unsigned int hdrlen; + unsigned char reset_pending_on_curr_blk; + unsigned char delete_blk_timer; + unsigned short kactive_blk_num; + unsigned short blk_sizeof_priv; + + /* last_kactive_blk_num: + * trick to see if user-space has caught up + * in order to avoid refreshing timer when every single pkt arrives. + */ + unsigned short last_kactive_blk_num; + + char *pkblk_start; + char *pkblk_end; + int kblk_size; + unsigned int knum_blocks; + uint64_t knxt_seq_num; + char *prev; + char *nxt_offset; + struct sk_buff *skb; + + atomic_t blk_fill_in_prog; + + /* Default is set to 8ms */ +#define DEFAULT_PRB_RETIRE_TOV (8) + + unsigned short retire_blk_tov; + unsigned short version; + unsigned long tov_in_jiffies; + + /* timer to retire an outstanding block */ + struct timer_list retire_blk_timer; +}; + +#define PGV_FROM_VMALLOC 1 struct pgv { char *buffer; }; @@ -179,12 +230,40 @@ struct packet_ring_buffer { unsigned int pg_vec_pages; unsigned int pg_vec_len; + struct kbdq_core prb_bdqc; atomic_t pending; }; +#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) +#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) +#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) +#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) +#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) +#define BLOCK_O2PRIV(x) ((x)->offset_to_priv) +#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) + struct packet_sock; static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); +static void *packet_previous_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status); +static void packet_increment_head(struct packet_ring_buffer *buff); +static int prb_curr_blk_in_use(struct kbdq_core *, + struct block_desc *); +static void *prb_dispatch_next_block(struct kbdq_core *, + struct packet_sock *); +static void prb_retire_current_block(struct kbdq_core *, + struct packet_sock *, unsigned int status); +static int prb_queue_frozen(struct kbdq_core *); +static void prb_open_block(struct kbdq_core *, struct block_desc *); +static void prb_retire_rx_blk_timer_expired(unsigned long); +static void _prb_refresh_rx_retire_blk_timer(struct kbdq_core *); +static void prb_init_blk_timer(struct packet_sock *, struct kbdq_core *, + void (*func) (unsigned long)); +static void prb_fill_rxhash(struct kbdq_core *, struct tpacket3_hdr *); +static void prb_clear_rxhash(struct kbdq_core *, struct tpacket3_hdr *); +static void prb_fill_vlan_info(struct kbdq_core *, struct tpacket3_hdr *); static void packet_flush_mclist(struct sock *sk); struct packet_fanout; @@ -193,6 +272,7 @@ struct packet_sock { struct sock sk; struct packet_fanout *fanout; struct tpacket_stats stats; + union tpacket_stats_u stats_u; struct packet_ring_buffer rx_ring; struct packet_ring_buffer tx_ring; int copy_thresh; @@ -242,6 +322,15 @@ struct packet_skb_cb { #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) +#define GET_PBDQC_FROM_RB(x) ((struct kbdq_core *)(&(x)->prb_bdqc)) +#define GET_PBLOCK_DESC(x, bid) \ + ((struct block_desc *)((x)->pkbdq[(bid)].buffer)) +#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ + ((struct block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) +#define GET_NEXT_PRB_BLK_NUM(x) \ + (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ + ((x)->kactive_blk_num+1) : 0) + static inline struct packet_sock *pkt_sk(struct sock *sk) { return (struct packet_sock *)sk; @@ -325,8 +414,9 @@ static void __packet_set_status(struct packet_sock *po, void *frame, int status) h.h2->tp_status = status; flush_dcache_page(pgv_to_page(&h.h2->tp_status)); break; + case TPACKET_V3: default: - pr_err("TPACKET version not supported\n"); + WARN(1, "TPACKET version not supported.\n"); BUG(); } @@ -351,8 +441,9 @@ static int __packet_get_status(struct packet_sock *po, void *frame) case TPACKET_V2: flush_dcache_page(pgv_to_page(&h.h2->tp_status)); return h.h2->tp_status; + case TPACKET_V3: default: - pr_err("TPACKET version not supported\n"); + WARN(1, "TPACKET version not supported.\n"); BUG(); return 0; } @@ -389,6 +480,665 @@ static inline void *packet_current_frame(struct packet_sock *po, return packet_lookup_frame(po, rb, rb->head, status); } +static void prb_del_retire_blk_timer(struct kbdq_core *pkc) +{ + del_timer_sync(&pkc->retire_blk_timer); +} + +static void prb_shutdown_retire_blk_timer(struct packet_sock *po, + int tx_ring, + struct sk_buff_head *rb_queue) +{ + struct kbdq_core *pkc; + + pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; + + spin_lock(&rb_queue->lock); + pkc->delete_blk_timer = 1; + spin_unlock(&rb_queue->lock); + + prb_del_retire_blk_timer(pkc); +} + +static void prb_init_blk_timer(struct packet_sock *po, + struct kbdq_core *pkc, + void (*func) (unsigned long)) +{ + init_timer(&pkc->retire_blk_timer); + pkc->retire_blk_timer.data = (long)po; + pkc->retire_blk_timer.function = func; + pkc->retire_blk_timer.expires = jiffies; +} + +static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) +{ + struct kbdq_core *pkc; + + if (tx_ring) + BUG(); + + pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; + prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); +} + +static int prb_calc_retire_blk_tmo(struct packet_sock *po, + int blk_size_in_bytes) +{ + struct net_device *dev; + unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; + + dev = dev_get_by_index(sock_net(&po->sk), po->ifindex); + if (unlikely(dev == NULL)) + return DEFAULT_PRB_RETIRE_TOV; + + if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { + struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; + + if (!dev->ethtool_ops->get_settings(dev, &ecmd)) { + switch (ecmd.speed) { + case SPEED_10000: + msec = 1; + div = 10000/1000; + break; + case SPEED_1000: + msec = 1; + div = 1000/1000; + break; + /* + * If the link speed is so slow you don't really + * need to worry about perf anyways + */ + case SPEED_100: + case SPEED_10: + default: + return DEFAULT_PRB_RETIRE_TOV; + } + } + } + + mbits = (blk_size_in_bytes * 8) / (1024 * 1024); + + if (div) + mbits /= div; + + tmo = mbits * msec; + + if (div) + return tmo+1; + return tmo; +} + +static void prb_init_ft_ops(struct kbdq_core *p1, + union tpacket_req_u *req_u) +{ + p1->feature_req_word = req_u->req3.tp_feature_req_word; +} + +static void init_prb_bdqc(struct packet_sock *po, + struct packet_ring_buffer *rb, + struct pgv *pg_vec, + union tpacket_req_u *req_u, int tx_ring) +{ + struct kbdq_core *p1 = &rb->prb_bdqc; + struct block_desc *pbd; + + memset(p1, 0x0, sizeof(*p1)); + + p1->knxt_seq_num = 1; + p1->pkbdq = pg_vec; + pbd = (struct block_desc *)pg_vec[0].buffer; + p1->pkblk_start = (char *)pg_vec[0].buffer; + p1->kblk_size = req_u->req3.tp_block_size; + p1->knum_blocks = req_u->req3.tp_block_nr; + p1->hdrlen = po->tp_hdrlen; + p1->version = po->tp_version; + p1->last_kactive_blk_num = 0; + po->stats_u.stats3.tp_freeze_q_cnt = 0; + if (req_u->req3.tp_retire_blk_tov) + p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; + else + p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, + req_u->req3.tp_block_size); + p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); + p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; + + prb_init_ft_ops(p1, req_u); + prb_setup_retire_blk_timer(po, tx_ring); + prb_open_block(p1, pbd); +} + +/* Do NOT update the last_blk_num first. + * Assumes sk_buff_head lock is held. + */ +static void _prb_refresh_rx_retire_blk_timer(struct kbdq_core *pkc) +{ + mod_timer(&pkc->retire_blk_timer, + jiffies + pkc->tov_in_jiffies); + pkc->last_kactive_blk_num = pkc->kactive_blk_num; +} + +/* + * Timer logic: + * 1) We refresh the timer only when we open a block. + * By doing this we don't waste cycles refreshing the timer + * on packet-by-packet basis. + * + * With a 1MB block-size, on a 1Gbps line, it will take + * i) ~8 ms to fill a block + ii) memcpy etc. + * In this cut we are not accounting for the memcpy time. + * + * So, if the user sets the 'tmo' to 10ms then the timer + * will never fire while the block is still getting filled + * (which is what we want). However, the user could choose + * to close a block early and that's fine. + * + * But when the timer does fire, we check whether or not to refresh it. + * Since the tmo granularity is in msecs, it is not too expensive + * to refresh the timer, lets say every '8' msecs. + * Either the user can set the 'tmo' or we can derive it based on + * a) line-speed and b) block-size. + * prb_calc_retire_blk_tmo() calculates the tmo. + * + */ +static void prb_retire_rx_blk_timer_expired(unsigned long data) +{ + struct packet_sock *po = (struct packet_sock *)data; + struct kbdq_core *pkc = &po->rx_ring.prb_bdqc; + unsigned int frozen; + struct block_desc *pbd; + + spin_lock(&po->sk.sk_receive_queue.lock); + + frozen = prb_queue_frozen(pkc); + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + if (unlikely(pkc->delete_blk_timer)) + goto out; + + /* We only need to plug the race when the block is partially filled. + * tpacket_rcv: + * lock(); increment BLOCK_NUM_PKTS; unlock() + * copy_bits() is in progress ... + * timer fires on other cpu: + * we can't retire the current block because copy_bits + * is in progress. + * + */ + if (BLOCK_NUM_PKTS(pbd)) { + while (atomic_read(&pkc->blk_fill_in_prog)) { + /* Waiting for skb_copy_bits to finish... */ + cpu_relax(); + } + } + + if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { + if (!frozen) { + prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); + if (!prb_dispatch_next_block(pkc, po)) + goto refresh_timer; + else + goto out; + } else { + /* Case 1. Queue was frozen because user-space was + * lagging behind. + */ + if (prb_curr_blk_in_use(pkc, pbd)) { + /* + * Ok, user-space is still behind. + * So just refresh the timer. + */ + goto refresh_timer; + } else { + /* Case 2. queue was frozen,user-space caught up, + * now the link went idle && the timer fired. + * We don't have a block to close.So we open this + * block and restart the timer. + * opening a block thaws the queue,restarts timer + * Thawing/timer-refresh is a side effect. + */ + prb_open_block(pkc, pbd); + goto out; + } + } + } + +refresh_timer: + _prb_refresh_rx_retire_blk_timer(pkc); + +out: + spin_unlock(&po->sk.sk_receive_queue.lock); +} + +static inline void prb_flush_block(struct kbdq_core *pkc1, + struct block_desc *pbd1, __u32 status) +{ + /* Flush everything minus the block header */ + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 + u8 *start, *end; + + start = (u8 *)pbd1; + + /* Skip the block header(we know header WILL fit in 4K) */ + start += PAGE_SIZE; + + end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); + for (; start < end; start += PAGE_SIZE) + flush_dcache_page(pgv_to_page(start)); + + smp_wmb(); +#endif + + /* Now update the block status. */ + + BLOCK_STATUS(pbd1) = status; + + /* Flush the block header */ + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 + start = (u8 *)pbd1; + flush_dcache_page(pgv_to_page(start)); + + smp_wmb(); +#endif +} + +/* + * Side effect: + * + * 1) flush the block + * 2) Increment active_blk_num + * + * Note:We DONT refresh the timer on purpose. + * Because almost always the next block will be opened. + */ +static void prb_close_block(struct kbdq_core *pkc1, struct block_desc *pbd1, + struct packet_sock *po, unsigned int stat) +{ + __u32 status = TP_STATUS_USER | stat; + + struct tpacket3_hdr *last_pkt; + struct hdr_v1 *h1 = &pbd1->hdr.bh1; + + if (po->stats.tp_drops) + status |= TP_STATUS_LOSING; + + last_pkt = (struct tpacket3_hdr *)pkc1->prev; + last_pkt->tp_next_offset = 0; + + /* Get the ts of the last pkt */ + if (BLOCK_NUM_PKTS(pbd1)) { + h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; + h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; + } else { + /* Ok, we tmo'd - so get the current time */ + struct timespec ts; + getnstimeofday(&ts); + h1->ts_last_pkt.ts_sec = ts.tv_sec; + h1->ts_last_pkt.ts_nsec = ts.tv_nsec; + } + + smp_wmb(); + + /* Flush the block */ + prb_flush_block(pkc1, pbd1, status); + + pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); +} + +static inline void prb_thaw_queue(struct kbdq_core *pkc) +{ + pkc->reset_pending_on_curr_blk = 0; +} + +/* + * Side effect of opening a block: + * + * 1) prb_queue is thawed. + * 2) retire_blk_timer is refreshed. + * + */ +static void prb_open_block(struct kbdq_core *pkc1, struct block_desc *pbd1) +{ + struct timespec ts; + struct hdr_v1 *h1 = &pbd1->hdr.bh1; + + smp_rmb(); + + if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { + + /* We could have just memset this but we will lose the + * flexibility of making the priv area sticky + */ + BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; + BLOCK_NUM_PKTS(pbd1) = 0; + BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); + getnstimeofday(&ts); + h1->ts_first_pkt.ts_sec = ts.tv_sec; + h1->ts_first_pkt.ts_nsec = ts.tv_nsec; + pkc1->pkblk_start = (char *)pbd1; + pkc1->nxt_offset = (char *)(pkc1->pkblk_start + + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv)); + BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); + BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; + pbd1->version = pkc1->version; + pkc1->prev = pkc1->nxt_offset; + pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; + prb_thaw_queue(pkc1); + _prb_refresh_rx_retire_blk_timer(pkc1); + + smp_wmb(); + + return; + } + + WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", + pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); + dump_stack(); + BUG(); +} + +/* + * Queue freeze logic: + * 1) Assume tp_block_nr = 8 blocks. + * 2) At time 't0', user opens Rx ring. + * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 + * 4) user-space is either sleeping or processing block '0'. + * 5) tpacket_rcv is currently filling block '7', since there is no space left, + * it will close block-7,loop around and try to fill block '0'. + * call-flow: + * __packet_lookup_frame_in_block + * prb_retire_current_block() + * prb_dispatch_next_block() + * |->(BLOCK_STATUS == USER) evaluates to true + * 5.1) Since block-0 is currently in-use, we just freeze the queue. + * 6) Now there are two cases: + * 6.1) Link goes idle right after the queue is frozen. + * But remember, the last open_block() refreshed the timer. + * When this timer expires,it will refresh itself so that we can + * re-open block-0 in near future. + * 6.2) Link is busy and keeps on receiving packets. This is a simple + * case and __packet_lookup_frame_in_block will check if block-0 + * is free and can now be re-used. + */ +static inline void prb_freeze_queue(struct kbdq_core *pkc, + struct packet_sock *po) +{ + pkc->reset_pending_on_curr_blk = 1; + po->stats_u.stats3.tp_freeze_q_cnt++; +} + +#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) + +/* + * If the next block is free then we will dispatch it + * and return a good offset. + * Else, we will freeze the queue. + * So, caller must check the return value. + */ +static void *prb_dispatch_next_block(struct kbdq_core *pkc, + struct packet_sock *po) +{ + struct block_desc *pbd; + + smp_rmb(); + + /* 1. Get current block num */ + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* 2. If this block is currently in_use then freeze the queue */ + if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { + prb_freeze_queue(pkc, po); + return NULL; + } + + /* + * 3. + * open this block and return the offset where the first packet + * needs to get stored. + */ + prb_open_block(pkc, pbd); + return (void *)pkc->nxt_offset; +} + +static void prb_retire_current_block(struct kbdq_core *pkc, + struct packet_sock *po, unsigned int status) +{ + struct block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* retire/close the current block */ + if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { + /* + * Plug the case where copy_bits() is in progress on + * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't + * have space to copy the pkt in the current block and + * called prb_retire_current_block() + * + * We don't need to worry about the TMO case because + * the timer-handler already handled this case. + */ + if (!(status & TP_STATUS_BLK_TMO)) { + while (atomic_read(&pkc->blk_fill_in_prog)) { + /* Waiting for skb_copy_bits to finish... */ + cpu_relax(); + } + } + prb_close_block(pkc, pbd, po, status); + return; + } + + WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); + dump_stack(); + BUG(); +} + +static inline int prb_curr_blk_in_use(struct kbdq_core *pkc, + struct block_desc *pbd) +{ + return TP_STATUS_USER & BLOCK_STATUS(pbd); +} + +static inline int prb_queue_frozen(struct kbdq_core *pkc) +{ + return pkc->reset_pending_on_curr_blk; +} + +static inline void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) +{ + struct kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); + atomic_dec(&pkc->blk_fill_in_prog); +} + +static inline void prb_fill_rxhash(struct kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); +} + +static inline void prb_clear_rxhash(struct kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + ppd->hv1.tp_rxhash = 0; +} + +static inline void prb_fill_vlan_info(struct kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + if (vlan_tx_tag_present(pkc->skb)) { + ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); + ppd->tp_status = TP_STATUS_VLAN_VALID; + } else { + ppd->hv1.tp_vlan_tci = ppd->tp_status = 0; + } +} + +static void prb_run_all_ft_ops(struct kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + prb_fill_vlan_info(pkc, ppd); + + if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) + prb_fill_rxhash(pkc, ppd); + else + prb_clear_rxhash(pkc, ppd); +} + +static inline void prb_fill_curr_block(char *curr, struct kbdq_core *pkc, + struct block_desc *pbd, + unsigned int len) +{ + struct tpacket3_hdr *ppd; + + ppd = (struct tpacket3_hdr *)curr; + ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); + pkc->prev = curr; + pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); + BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); + BLOCK_NUM_PKTS(pbd) += 1; + atomic_inc(&pkc->blk_fill_in_prog); + prb_run_all_ft_ops(pkc, ppd); +} + +/* Assumes caller has the sk->rx_queue.lock */ +static void *__packet_lookup_frame_in_block(struct packet_sock *po, + struct sk_buff *skb, + int status, + unsigned int len + ) +{ + struct kbdq_core *pkc; + struct block_desc *pbd; + char *curr, *end; + + pkc = GET_PBDQC_FROM_RB(((struct packet_ring_buffer *)&po->rx_ring)); + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* Queue is frozen when user space is lagging behind */ + if (prb_queue_frozen(pkc)) { + /* + * Check if that last block which caused the queue to freeze, + * is still in_use by user-space. + */ + if (prb_curr_blk_in_use(pkc, pbd)) { + /* Can't record this packet */ + return NULL; + } else { + /* + * Ok, the block was released by user-space. + * Now let's open that block. + * opening a block also thaws the queue. + * Thawing is a side effect. + */ + prb_open_block(pkc, pbd); + } + } + + smp_mb(); + curr = pkc->nxt_offset; + pkc->skb = skb; + end = (char *) ((char *)pbd + pkc->kblk_size); + + /* first try the current block */ + if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { + prb_fill_curr_block(curr, pkc, pbd, len); + return (void *)curr; + } + + /* Ok, close the current block */ + prb_retire_current_block(pkc, po, 0); + + /* Now, try to dispatch the next block */ + curr = (char *)prb_dispatch_next_block(pkc, po); + if (curr) { + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + prb_fill_curr_block(curr, pkc, pbd, len); + return (void *)curr; + } + + /* + * No free blocks are available.user_space hasn't caught up yet. + * Queue was just frozen and now this packet will get dropped. + */ + return NULL; +} + +static inline void *packet_current_rx_frame(struct packet_sock *po, + struct sk_buff *skb, + int status, unsigned int len) +{ + char *curr = NULL; + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + curr = packet_lookup_frame(po, &po->rx_ring, + po->rx_ring.head, status); + return curr; + case TPACKET_V3: + return __packet_lookup_frame_in_block(po, skb, status, len); + default: + WARN(1, "TPACKET version not supported\n"); + BUG(); + return 0; + } +} + +static inline void *prb_lookup_block(struct packet_sock *po, + struct packet_ring_buffer *rb, + unsigned int previous, + int status) +{ + struct kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); + struct block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); + + if (status != BLOCK_STATUS(pbd)) + return NULL; + return pbd; +} + +static inline int prb_previous_blk_num(struct packet_ring_buffer *rb) +{ + unsigned int prev; + if (rb->prb_bdqc.kactive_blk_num) + prev = rb->prb_bdqc.kactive_blk_num-1; + else + prev = rb->prb_bdqc.knum_blocks-1; + return prev; +} + +/* Assumes caller has held the rx_queue.lock */ +static inline void *__prb_previous_block(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + unsigned int previous = prb_previous_blk_num(rb); + return prb_lookup_block(po, rb, previous, status); +} + +static inline void *packet_previous_rx_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + if (po->tp_version <= TPACKET_V2) + return packet_previous_frame(po, rb, status); + + return __prb_previous_block(po, rb, status); +} + +static inline void packet_increment_rx_head(struct packet_sock *po, + struct packet_ring_buffer *rb) +{ + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + return packet_increment_head(rb); + case TPACKET_V3: + default: + WARN(1, "TPACKET version not supported.\n"); + BUG(); + return; + } +} + static inline void *packet_previous_frame(struct packet_sock *po, struct packet_ring_buffer *rb, int status) @@ -982,12 +1732,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; + struct tpacket3_hdr *h3; void *raw; } h; u8 *skb_head = skb->data; int skb_len = skb->len; unsigned int snaplen, res; - unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER; + unsigned long status = TP_STATUS_USER; unsigned short macoff, netoff, hdrlen; struct sk_buff *copy_skb = NULL; struct timeval tv; @@ -1033,37 +1784,46 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, po->tp_reserve; macoff = netoff - maclen; } - - if (macoff + snaplen > po->rx_ring.frame_size) { - if (po->copy_thresh && - atomic_read(&sk->sk_rmem_alloc) + skb->truesize < - (unsigned)sk->sk_rcvbuf) { - if (skb_shared(skb)) { - copy_skb = skb_clone(skb, GFP_ATOMIC); - } else { - copy_skb = skb_get(skb); - skb_head = skb->data; + if (po->tp_version <= TPACKET_V2) { + if (macoff + snaplen > po->rx_ring.frame_size) { + if (po->copy_thresh && + atomic_read(&sk->sk_rmem_alloc) + skb->truesize + < (unsigned)sk->sk_rcvbuf) { + if (skb_shared(skb)) { + copy_skb = skb_clone(skb, GFP_ATOMIC); + } else { + copy_skb = skb_get(skb); + skb_head = skb->data; + } + if (copy_skb) + skb_set_owner_r(copy_skb, sk); } - if (copy_skb) - skb_set_owner_r(copy_skb, sk); + snaplen = po->rx_ring.frame_size - macoff; + if ((int)snaplen < 0) + snaplen = 0; } - snaplen = po->rx_ring.frame_size - macoff; - if ((int)snaplen < 0) - snaplen = 0; } - spin_lock(&sk->sk_receive_queue.lock); - h.raw = packet_current_frame(po, &po->rx_ring, TP_STATUS_KERNEL); + h.raw = packet_current_rx_frame(po, skb, + TP_STATUS_KERNEL, (macoff+snaplen)); if (!h.raw) goto ring_is_full; - packet_increment_head(&po->rx_ring); + if (po->tp_version <= TPACKET_V2) { + packet_increment_rx_head(po, &po->rx_ring); + /* + * LOSING will be reported till you read the stats, + * because it's COR - Clear On Read. + * Anyways, moving it for V1/V2 only as V3 doesn't need this + * at packet level. + */ + if (po->stats.tp_drops) + status |= TP_STATUS_LOSING; + } po->stats.tp_packets++; if (copy_skb) { status |= TP_STATUS_COPY; __skb_queue_tail(&sk->sk_receive_queue, copy_skb); } - if (!po->stats.tp_drops) - status &= ~TP_STATUS_LOSING; spin_unlock(&sk->sk_receive_queue.lock); skb_copy_bits(skb, 0, h.raw + macoff, snaplen); @@ -1114,6 +1874,29 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, h.h2->tp_padding = 0; hdrlen = sizeof(*h.h2); break; + case TPACKET_V3: + /* tp_nxt_offset,vlan are already populated above. + * So DONT clear those fields here + */ + h.h3->tp_status |= status; + h.h3->tp_len = skb->len; + h.h3->tp_snaplen = snaplen; + h.h3->tp_mac = macoff; + h.h3->tp_net = netoff; + if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) + && shhwtstamps->syststamp.tv64) + ts = ktime_to_timespec(shhwtstamps->syststamp); + else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) + && shhwtstamps->hwtstamp.tv64) + ts = ktime_to_timespec(shhwtstamps->hwtstamp); + else if (skb->tstamp.tv64) + ts = ktime_to_timespec(skb->tstamp); + else + getnstimeofday(&ts); + h.h3->tp_sec = ts.tv_sec; + h.h3->tp_nsec = ts.tv_nsec; + hdrlen = sizeof(*h.h3); + break; default: BUG(); } @@ -1134,13 +1917,19 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, { u8 *start, *end; - end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + macoff + snaplen); - for (start = h.raw; start < end; start += PAGE_SIZE) - flush_dcache_page(pgv_to_page(start)); + if (po->tp_version <= TPACKET_V2) { + end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + + macoff + snaplen); + for (start = h.raw; start < end; start += PAGE_SIZE) + flush_dcache_page(pgv_to_page(start)); + } smp_wmb(); } #endif - __packet_set_status(po, h.raw, status); + if (po->tp_version <= TPACKET_V2) + __packet_set_status(po, h.raw, status); + else + prb_clear_blk_fill_status(&po->rx_ring); sk->sk_data_ready(sk, 0); @@ -1631,7 +2420,7 @@ static int packet_release(struct socket *sock) struct sock *sk = sock->sk; struct packet_sock *po; struct net *net; - struct tpacket_req req; + union tpacket_req_u req_u; if (!sk) return 0; @@ -1654,13 +2443,13 @@ static int packet_release(struct socket *sock) packet_flush_mclist(sk); - memset(&req, 0, sizeof(req)); + memset(&req_u, 0, sizeof(req_u)); if (po->rx_ring.pg_vec) - packet_set_ring(sk, &req, 1, 0); + packet_set_ring(sk, &req_u, 1, 0); if (po->tx_ring.pg_vec) - packet_set_ring(sk, &req, 1, 1); + packet_set_ring(sk, &req_u, 1, 1); fanout_release(sk); @@ -2280,15 +3069,27 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv case PACKET_RX_RING: case PACKET_TX_RING: { - struct tpacket_req req; + union tpacket_req_u req_u; + int len; - if (optlen < sizeof(req)) + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + len = sizeof(req_u.req); + break; + case TPACKET_V3: + default: + len = sizeof(req_u.req3); + break; + } + if (optlen < len) return -EINVAL; if (pkt_sk(sk)->has_vnet_hdr) return -EINVAL; - if (copy_from_user(&req, optval, sizeof(req))) + if (copy_from_user(&req_u.req, optval, len)) return -EFAULT; - return packet_set_ring(sk, &req, 0, optname == PACKET_TX_RING); + return packet_set_ring(sk, &req_u, 0, + optname == PACKET_TX_RING); } case PACKET_COPY_THRESH: { @@ -2315,6 +3116,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv switch (val) { case TPACKET_V1: case TPACKET_V2: + case TPACKET_V3: po->tp_version = val; return 0; default: @@ -2424,6 +3226,7 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, struct packet_sock *po = pkt_sk(sk); void *data; struct tpacket_stats st; + union tpacket_stats_u st_u; if (level != SOL_PACKET) return -ENOPROTOOPT; @@ -2436,15 +3239,27 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, switch (optname) { case PACKET_STATISTICS: - if (len > sizeof(struct tpacket_stats)) - len = sizeof(struct tpacket_stats); + if (po->tp_version == TPACKET_V3) { + len = sizeof(struct tpacket_stats_v3); + } else { + if (len > sizeof(struct tpacket_stats)) + len = sizeof(struct tpacket_stats); + } spin_lock_bh(&sk->sk_receive_queue.lock); - st = po->stats; + if (po->tp_version == TPACKET_V3) { + memcpy(&st_u.stats3, &po->stats, + sizeof(struct tpacket_stats)); + st_u.stats3.tp_freeze_q_cnt = + po->stats_u.stats3.tp_freeze_q_cnt; + st_u.stats3.tp_packets += po->stats.tp_drops; + data = &st_u.stats3; + } else { + st = po->stats; + st.tp_packets += st.tp_drops; + data = &st; + } memset(&po->stats, 0, sizeof(st)); spin_unlock_bh(&sk->sk_receive_queue.lock); - st.tp_packets += st.tp_drops; - - data = &st; break; case PACKET_AUXDATA: if (len > sizeof(int)) @@ -2485,6 +3300,9 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, case TPACKET_V2: val = sizeof(struct tpacket2_hdr); break; + case TPACKET_V3: + val = sizeof(struct tpacket3_hdr); + break; default: return -EINVAL; } @@ -2641,7 +3459,8 @@ static unsigned int packet_poll(struct file *file, struct socket *sock, spin_lock_bh(&sk->sk_receive_queue.lock); if (po->rx_ring.pg_vec) { - if (!packet_previous_frame(po, &po->rx_ring, TP_STATUS_KERNEL)) + if (!packet_previous_rx_frame(po, &po->rx_ring, + TP_STATUS_KERNEL)) mask |= POLLIN | POLLRDNORM; } spin_unlock_bh(&sk->sk_receive_queue.lock); @@ -2760,7 +3579,7 @@ out_free_pgvec: goto out; } -static int packet_set_ring(struct sock *sk, struct tpacket_req *req, +static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, int closing, int tx_ring) { struct pgv *pg_vec = NULL; @@ -2769,7 +3588,15 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, struct packet_ring_buffer *rb; struct sk_buff_head *rb_queue; __be16 num; - int err; + int err = -EINVAL; + /* Added to avoid minimal code churn */ + struct tpacket_req *req = &req_u->req; + + /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ + if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { + WARN(1, "Tx-ring is not supported.\n"); + goto out; + } rb = tx_ring ? &po->tx_ring : &po->rx_ring; rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; @@ -2795,6 +3622,9 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, case TPACKET_V2: po->tp_hdrlen = TPACKET2_HDRLEN; break; + case TPACKET_V3: + po->tp_hdrlen = TPACKET3_HDRLEN; + break; } err = -EINVAL; @@ -2820,6 +3650,17 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, pg_vec = alloc_pg_vec(req, order); if (unlikely(!pg_vec)) goto out; + switch (po->tp_version) { + case TPACKET_V3: + /* Transmit path is not supported. We checked + * it above but just being paranoid + */ + if (!tx_ring) + init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); + break; + default: + break; + } } /* Done */ else { @@ -2872,7 +3713,11 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, register_prot_hook(sk); } spin_unlock(&po->bind_lock); - + if (closing && (po->tp_version > TPACKET_V2)) { + /* Because we don't support block-based V3 on tx-ring */ + if (!tx_ring) + prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); + } release_sock(sk); if (pg_vec) |
