| /* |
| * Back-end of the driver for virtual network devices. This portion of the |
| * driver exports a 'unified' network-device interface that can be accessed |
| * by any operating system that implements a compatible front end. A |
| * reference front-end implementation can be found in: |
| * drivers/net/xen-netfront.c |
| * |
| * Copyright (c) 2002-2005, K A Fraser |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version 2 |
| * as published by the Free Software Foundation; or, when distributed |
| * separately from the Linux kernel or incorporated into other |
| * software packages, subject to the following license: |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this source file (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, modify, |
| * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| * and to permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include "common.h" |
| |
| #include <linux/kthread.h> |
| #include <linux/if_vlan.h> |
| #include <linux/udp.h> |
| |
| #include <net/tcp.h> |
| |
| #include <xen/xen.h> |
| #include <xen/events.h> |
| #include <xen/interface/memory.h> |
| |
| #include <asm/xen/hypercall.h> |
| #include <asm/xen/page.h> |
| |
| /* Provide an option to disable split event channels at load time as |
| * event channels are limited resource. Split event channels are |
| * enabled by default. |
| */ |
| bool separate_tx_rx_irq = 1; |
| module_param(separate_tx_rx_irq, bool, 0644); |
| |
| /* |
| * This is the maximum slots a skb can have. If a guest sends a skb |
| * which exceeds this limit it is considered malicious. |
| */ |
| #define FATAL_SKB_SLOTS_DEFAULT 20 |
| static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT; |
| module_param(fatal_skb_slots, uint, 0444); |
| |
| /* |
| * To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating |
| * the maximum slots a valid packet can use. Now this value is defined |
| * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by |
| * all backend. |
| */ |
| #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN |
| |
| /* |
| * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of |
| * one or more merged tx requests, otherwise it is the continuation of |
| * previous tx request. |
| */ |
| static inline int pending_tx_is_head(struct xenvif *vif, RING_IDX idx) |
| { |
| return vif->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX; |
| } |
| |
| static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, |
| u8 status); |
| |
| static void make_tx_response(struct xenvif *vif, |
| struct xen_netif_tx_request *txp, |
| s8 st); |
| |
| static inline int tx_work_todo(struct xenvif *vif); |
| static inline int rx_work_todo(struct xenvif *vif); |
| |
| static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, |
| u16 id, |
| s8 st, |
| u16 offset, |
| u16 size, |
| u16 flags); |
| |
| static inline unsigned long idx_to_pfn(struct xenvif *vif, |
| u16 idx) |
| { |
| return page_to_pfn(vif->mmap_pages[idx]); |
| } |
| |
| static inline unsigned long idx_to_kaddr(struct xenvif *vif, |
| u16 idx) |
| { |
| return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx)); |
| } |
| |
| /* This is a miniumum size for the linear area to avoid lots of |
| * calls to __pskb_pull_tail() as we set up checksum offsets. The |
| * value 128 was chosen as it covers all IPv4 and most likely |
| * IPv6 headers. |
| */ |
| #define PKT_PROT_LEN 128 |
| |
| static u16 frag_get_pending_idx(skb_frag_t *frag) |
| { |
| return (u16)frag->page_offset; |
| } |
| |
| static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx) |
| { |
| frag->page_offset = pending_idx; |
| } |
| |
| static inline pending_ring_idx_t pending_index(unsigned i) |
| { |
| return i & (MAX_PENDING_REQS-1); |
| } |
| |
| static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif) |
| { |
| return MAX_PENDING_REQS - |
| vif->pending_prod + vif->pending_cons; |
| } |
| |
| static int max_required_rx_slots(struct xenvif *vif) |
| { |
| int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE); |
| |
| /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */ |
| if (vif->can_sg || vif->gso || vif->gso_prefix) |
| max += MAX_SKB_FRAGS + 1; /* extra_info + frags */ |
| |
| return max; |
| } |
| |
| int xenvif_rx_ring_full(struct xenvif *vif) |
| { |
| RING_IDX peek = vif->rx_req_cons_peek; |
| RING_IDX needed = max_required_rx_slots(vif); |
| |
| return ((vif->rx.sring->req_prod - peek) < needed) || |
| ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) < needed); |
| } |
| |
| int xenvif_must_stop_queue(struct xenvif *vif) |
| { |
| if (!xenvif_rx_ring_full(vif)) |
| return 0; |
| |
| vif->rx.sring->req_event = vif->rx_req_cons_peek + |
| max_required_rx_slots(vif); |
| mb(); /* request notification /then/ check the queue */ |
| |
| return xenvif_rx_ring_full(vif); |
| } |
| |
| /* |
| * Returns true if we should start a new receive buffer instead of |
| * adding 'size' bytes to a buffer which currently contains 'offset' |
| * bytes. |
| */ |
| static bool start_new_rx_buffer(int offset, unsigned long size, int head) |
| { |
| /* simple case: we have completely filled the current buffer. */ |
| if (offset == MAX_BUFFER_OFFSET) |
| return true; |
| |
| /* |
| * complex case: start a fresh buffer if the current frag |
| * would overflow the current buffer but only if: |
| * (i) this frag would fit completely in the next buffer |
| * and (ii) there is already some data in the current buffer |
| * and (iii) this is not the head buffer. |
| * |
| * Where: |
| * - (i) stops us splitting a frag into two copies |
| * unless the frag is too large for a single buffer. |
| * - (ii) stops us from leaving a buffer pointlessly empty. |
| * - (iii) stops us leaving the first buffer |
| * empty. Strictly speaking this is already covered |
| * by (ii) but is explicitly checked because |
| * netfront relies on the first buffer being |
| * non-empty and can crash otherwise. |
| * |
| * This means we will effectively linearise small |
| * frags but do not needlessly split large buffers |
| * into multiple copies tend to give large frags their |
| * own buffers as before. |
| */ |
| if ((offset + size > MAX_BUFFER_OFFSET) && |
| (size <= MAX_BUFFER_OFFSET) && offset && !head) |
| return true; |
| |
| return false; |
| } |
| |
| struct xenvif_count_slot_state { |
| unsigned long copy_off; |
| bool head; |
| }; |
| |
| unsigned int xenvif_count_frag_slots(struct xenvif *vif, |
| unsigned long offset, unsigned long size, |
| struct xenvif_count_slot_state *state) |
| { |
| unsigned count = 0; |
| |
| offset &= ~PAGE_MASK; |
| |
| while (size > 0) { |
| unsigned long bytes; |
| |
| bytes = PAGE_SIZE - offset; |
| |
| if (bytes > size) |
| bytes = size; |
| |
| if (start_new_rx_buffer(state->copy_off, bytes, state->head)) { |
| count++; |
| state->copy_off = 0; |
| } |
| |
| if (state->copy_off + bytes > MAX_BUFFER_OFFSET) |
| bytes = MAX_BUFFER_OFFSET - state->copy_off; |
| |
| state->copy_off += bytes; |
| |
| offset += bytes; |
| size -= bytes; |
| |
| if (offset == PAGE_SIZE) |
| offset = 0; |
| |
| state->head = false; |
| } |
| |
| return count; |
| } |
| |
| /* |
| * Figure out how many ring slots we're going to need to send @skb to |
| * the guest. This function is essentially a dry run of |
| * xenvif_gop_frag_copy. |
| */ |
| unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb) |
| { |
| struct xenvif_count_slot_state state; |
| unsigned int count; |
| unsigned char *data; |
| unsigned i; |
| |
| state.head = true; |
| state.copy_off = 0; |
| |
| /* Slot for the first (partial) page of data. */ |
| count = 1; |
| |
| /* Need a slot for the GSO prefix for GSO extra data? */ |
| if (skb_shinfo(skb)->gso_size) |
| count++; |
| |
| data = skb->data; |
| while (data < skb_tail_pointer(skb)) { |
| unsigned long offset = offset_in_page(data); |
| unsigned long size = PAGE_SIZE - offset; |
| |
| if (data + size > skb_tail_pointer(skb)) |
| size = skb_tail_pointer(skb) - data; |
| |
| count += xenvif_count_frag_slots(vif, offset, size, &state); |
| |
| data += size; |
| } |
| |
| for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| unsigned long size = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
| unsigned long offset = skb_shinfo(skb)->frags[i].page_offset; |
| |
| count += xenvif_count_frag_slots(vif, offset, size, &state); |
| } |
| return count; |
| } |
| |
| struct netrx_pending_operations { |
| unsigned copy_prod, copy_cons; |
| unsigned meta_prod, meta_cons; |
| struct gnttab_copy *copy; |
| struct xenvif_rx_meta *meta; |
| int copy_off; |
| grant_ref_t copy_gref; |
| }; |
| |
| static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif, |
| struct netrx_pending_operations *npo) |
| { |
| struct xenvif_rx_meta *meta; |
| struct xen_netif_rx_request *req; |
| |
| req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| |
| meta = npo->meta + npo->meta_prod++; |
| meta->gso_size = 0; |
| meta->size = 0; |
| meta->id = req->id; |
| |
| npo->copy_off = 0; |
| npo->copy_gref = req->gref; |
| |
| return meta; |
| } |
| |
| /* |
| * Set up the grant operations for this fragment. If it's a flipping |
| * interface, we also set up the unmap request from here. |
| */ |
| static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, |
| struct netrx_pending_operations *npo, |
| struct page *page, unsigned long size, |
| unsigned long offset, int *head) |
| { |
| struct gnttab_copy *copy_gop; |
| struct xenvif_rx_meta *meta; |
| unsigned long bytes; |
| |
| /* Data must not cross a page boundary. */ |
| BUG_ON(size + offset > PAGE_SIZE<<compound_order(page)); |
| |
| meta = npo->meta + npo->meta_prod - 1; |
| |
| /* Skip unused frames from start of page */ |
| page += offset >> PAGE_SHIFT; |
| offset &= ~PAGE_MASK; |
| |
| while (size > 0) { |
| BUG_ON(offset >= PAGE_SIZE); |
| BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET); |
| |
| bytes = PAGE_SIZE - offset; |
| |
| if (bytes > size) |
| bytes = size; |
| |
| if (start_new_rx_buffer(npo->copy_off, bytes, *head)) { |
| /* |
| * Netfront requires there to be some data in the head |
| * buffer. |
| */ |
| BUG_ON(*head); |
| |
| meta = get_next_rx_buffer(vif, npo); |
| } |
| |
| if (npo->copy_off + bytes > MAX_BUFFER_OFFSET) |
| bytes = MAX_BUFFER_OFFSET - npo->copy_off; |
| |
| copy_gop = npo->copy + npo->copy_prod++; |
| copy_gop->flags = GNTCOPY_dest_gref; |
| copy_gop->len = bytes; |
| |
| copy_gop->source.domid = DOMID_SELF; |
| copy_gop->source.u.gmfn = virt_to_mfn(page_address(page)); |
| copy_gop->source.offset = offset; |
| |
| copy_gop->dest.domid = vif->domid; |
| copy_gop->dest.offset = npo->copy_off; |
| copy_gop->dest.u.ref = npo->copy_gref; |
| |
| npo->copy_off += bytes; |
| meta->size += bytes; |
| |
| offset += bytes; |
| size -= bytes; |
| |
| /* Next frame */ |
| if (offset == PAGE_SIZE && size) { |
| BUG_ON(!PageCompound(page)); |
| page++; |
| offset = 0; |
| } |
| |
| /* Leave a gap for the GSO descriptor. */ |
| if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix) |
| vif->rx.req_cons++; |
| |
| *head = 0; /* There must be something in this buffer now. */ |
| |
| } |
| } |
| |
| /* |
| * Prepare an SKB to be transmitted to the frontend. |
| * |
| * This function is responsible for allocating grant operations, meta |
| * structures, etc. |
| * |
| * It returns the number of meta structures consumed. The number of |
| * ring slots used is always equal to the number of meta slots used |
| * plus the number of GSO descriptors used. Currently, we use either |
| * zero GSO descriptors (for non-GSO packets) or one descriptor (for |
| * frontend-side LRO). |
| */ |
| static int xenvif_gop_skb(struct sk_buff *skb, |
| struct netrx_pending_operations *npo) |
| { |
| struct xenvif *vif = netdev_priv(skb->dev); |
| int nr_frags = skb_shinfo(skb)->nr_frags; |
| int i; |
| struct xen_netif_rx_request *req; |
| struct xenvif_rx_meta *meta; |
| unsigned char *data; |
| int head = 1; |
| int old_meta_prod; |
| |
| old_meta_prod = npo->meta_prod; |
| |
| /* Set up a GSO prefix descriptor, if necessary */ |
| if (skb_shinfo(skb)->gso_size && vif->gso_prefix) { |
| req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| meta = npo->meta + npo->meta_prod++; |
| meta->gso_size = skb_shinfo(skb)->gso_size; |
| meta->size = 0; |
| meta->id = req->id; |
| } |
| |
| req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| meta = npo->meta + npo->meta_prod++; |
| |
| if (!vif->gso_prefix) |
| meta->gso_size = skb_shinfo(skb)->gso_size; |
| else |
| meta->gso_size = 0; |
| |
| meta->size = 0; |
| meta->id = req->id; |
| npo->copy_off = 0; |
| npo->copy_gref = req->gref; |
| |
| data = skb->data; |
| while (data < skb_tail_pointer(skb)) { |
| unsigned int offset = offset_in_page(data); |
| unsigned int len = PAGE_SIZE - offset; |
| |
| if (data + len > skb_tail_pointer(skb)) |
| len = skb_tail_pointer(skb) - data; |
| |
| xenvif_gop_frag_copy(vif, skb, npo, |
| virt_to_page(data), len, offset, &head); |
| data += len; |
| } |
| |
| for (i = 0; i < nr_frags; i++) { |
| xenvif_gop_frag_copy(vif, skb, npo, |
| skb_frag_page(&skb_shinfo(skb)->frags[i]), |
| skb_frag_size(&skb_shinfo(skb)->frags[i]), |
| skb_shinfo(skb)->frags[i].page_offset, |
| &head); |
| } |
| |
| return npo->meta_prod - old_meta_prod; |
| } |
| |
| /* |
| * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was |
| * used to set up the operations on the top of |
| * netrx_pending_operations, which have since been done. Check that |
| * they didn't give any errors and advance over them. |
| */ |
| static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots, |
| struct netrx_pending_operations *npo) |
| { |
| struct gnttab_copy *copy_op; |
| int status = XEN_NETIF_RSP_OKAY; |
| int i; |
| |
| for (i = 0; i < nr_meta_slots; i++) { |
| copy_op = npo->copy + npo->copy_cons++; |
| if (copy_op->status != GNTST_okay) { |
| netdev_dbg(vif->dev, |
| "Bad status %d from copy to DOM%d.\n", |
| copy_op->status, vif->domid); |
| status = XEN_NETIF_RSP_ERROR; |
| } |
| } |
| |
| return status; |
| } |
| |
| static void xenvif_add_frag_responses(struct xenvif *vif, int status, |
| struct xenvif_rx_meta *meta, |
| int nr_meta_slots) |
| { |
| int i; |
| unsigned long offset; |
| |
| /* No fragments used */ |
| if (nr_meta_slots <= 1) |
| return; |
| |
| nr_meta_slots--; |
| |
| for (i = 0; i < nr_meta_slots; i++) { |
| int flags; |
| if (i == nr_meta_slots - 1) |
| flags = 0; |
| else |
| flags = XEN_NETRXF_more_data; |
| |
| offset = 0; |
| make_rx_response(vif, meta[i].id, status, offset, |
| meta[i].size, flags); |
| } |
| } |
| |
| struct skb_cb_overlay { |
| int meta_slots_used; |
| }; |
| |
| static void xenvif_kick_thread(struct xenvif *vif) |
| { |
| wake_up(&vif->wq); |
| } |
| |
| void xenvif_rx_action(struct xenvif *vif) |
| { |
| s8 status; |
| u16 flags; |
| struct xen_netif_rx_response *resp; |
| struct sk_buff_head rxq; |
| struct sk_buff *skb; |
| LIST_HEAD(notify); |
| int ret; |
| int nr_frags; |
| int count; |
| unsigned long offset; |
| struct skb_cb_overlay *sco; |
| int need_to_notify = 0; |
| |
| struct netrx_pending_operations npo = { |
| .copy = vif->grant_copy_op, |
| .meta = vif->meta, |
| }; |
| |
| skb_queue_head_init(&rxq); |
| |
| count = 0; |
| |
| while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) { |
| vif = netdev_priv(skb->dev); |
| nr_frags = skb_shinfo(skb)->nr_frags; |
| |
| sco = (struct skb_cb_overlay *)skb->cb; |
| sco->meta_slots_used = xenvif_gop_skb(skb, &npo); |
| |
| count += nr_frags + 1; |
| |
| __skb_queue_tail(&rxq, skb); |
| |
| /* Filled the batch queue? */ |
| /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */ |
| if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE) |
| break; |
| } |
| |
| BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta)); |
| |
| if (!npo.copy_prod) |
| return; |
| |
| BUG_ON(npo.copy_prod > ARRAY_SIZE(vif->grant_copy_op)); |
| gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod); |
| |
| while ((skb = __skb_dequeue(&rxq)) != NULL) { |
| sco = (struct skb_cb_overlay *)skb->cb; |
| |
| vif = netdev_priv(skb->dev); |
| |
| if (vif->meta[npo.meta_cons].gso_size && vif->gso_prefix) { |
| resp = RING_GET_RESPONSE(&vif->rx, |
| vif->rx.rsp_prod_pvt++); |
| |
| resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data; |
| |
| resp->offset = vif->meta[npo.meta_cons].gso_size; |
| resp->id = vif->meta[npo.meta_cons].id; |
| resp->status = sco->meta_slots_used; |
| |
| npo.meta_cons++; |
| sco->meta_slots_used--; |
| } |
| |
| |
| vif->dev->stats.tx_bytes += skb->len; |
| vif->dev->stats.tx_packets++; |
| |
| status = xenvif_check_gop(vif, sco->meta_slots_used, &npo); |
| |
| if (sco->meta_slots_used == 1) |
| flags = 0; |
| else |
| flags = XEN_NETRXF_more_data; |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ |
| flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated; |
| else if (skb->ip_summed == CHECKSUM_UNNECESSARY) |
| /* remote but checksummed. */ |
| flags |= XEN_NETRXF_data_validated; |
| |
| offset = 0; |
| resp = make_rx_response(vif, vif->meta[npo.meta_cons].id, |
| status, offset, |
| vif->meta[npo.meta_cons].size, |
| flags); |
| |
| if (vif->meta[npo.meta_cons].gso_size && !vif->gso_prefix) { |
| struct xen_netif_extra_info *gso = |
| (struct xen_netif_extra_info *) |
| RING_GET_RESPONSE(&vif->rx, |
| vif->rx.rsp_prod_pvt++); |
| |
| resp->flags |= XEN_NETRXF_extra_info; |
| |
| gso->u.gso.size = vif->meta[npo.meta_cons].gso_size; |
| gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; |
| gso->u.gso.pad = 0; |
| gso->u.gso.features = 0; |
| |
| gso->type = XEN_NETIF_EXTRA_TYPE_GSO; |
| gso->flags = 0; |
| } |
| |
| xenvif_add_frag_responses(vif, status, |
| vif->meta + npo.meta_cons + 1, |
| sco->meta_slots_used); |
| |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret); |
| |
| if (ret) |
| need_to_notify = 1; |
| |
| xenvif_notify_tx_completion(vif); |
| |
| npo.meta_cons += sco->meta_slots_used; |
| dev_kfree_skb(skb); |
| } |
| |
| if (need_to_notify) |
| notify_remote_via_irq(vif->rx_irq); |
| |
| /* More work to do? */ |
| if (!skb_queue_empty(&vif->rx_queue)) |
| xenvif_kick_thread(vif); |
| } |
| |
| void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb) |
| { |
| skb_queue_tail(&vif->rx_queue, skb); |
| |
| xenvif_kick_thread(vif); |
| } |
| |
| void xenvif_check_rx_xenvif(struct xenvif *vif) |
| { |
| int more_to_do; |
| |
| RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do); |
| |
| if (more_to_do) |
| napi_schedule(&vif->napi); |
| } |
| |
| static void tx_add_credit(struct xenvif *vif) |
| { |
| unsigned long max_burst, max_credit; |
| |
| /* |
| * Allow a burst big enough to transmit a jumbo packet of up to 128kB. |
| * Otherwise the interface can seize up due to insufficient credit. |
| */ |
| max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; |
| max_burst = min(max_burst, 131072UL); |
| max_burst = max(max_burst, vif->credit_bytes); |
| |
| /* Take care that adding a new chunk of credit doesn't wrap to zero. */ |
| max_credit = vif->remaining_credit + vif->credit_bytes; |
| if (max_credit < vif->remaining_credit) |
| max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ |
| |
| vif->remaining_credit = min(max_credit, max_burst); |
| } |
| |
| static void tx_credit_callback(unsigned long data) |
| { |
| struct xenvif *vif = (struct xenvif *)data; |
| tx_add_credit(vif); |
| xenvif_check_rx_xenvif(vif); |
| } |
| |
| static void xenvif_tx_err(struct xenvif *vif, |
| struct xen_netif_tx_request *txp, RING_IDX end) |
| { |
| RING_IDX cons = vif->tx.req_cons; |
| |
| do { |
| make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR); |
| if (cons == end) |
| break; |
| txp = RING_GET_REQUEST(&vif->tx, cons++); |
| } while (1); |
| vif->tx.req_cons = cons; |
| } |
| |
| static void xenvif_fatal_tx_err(struct xenvif *vif) |
| { |
| netdev_err(vif->dev, "fatal error; disabling device\n"); |
| xenvif_carrier_off(vif); |
| } |
| |
| static int xenvif_count_requests(struct xenvif *vif, |
| struct xen_netif_tx_request *first, |
| struct xen_netif_tx_request *txp, |
| int work_to_do) |
| { |
| RING_IDX cons = vif->tx.req_cons; |
| int slots = 0; |
| int drop_err = 0; |
| int more_data; |
| |
| if (!(first->flags & XEN_NETTXF_more_data)) |
| return 0; |
| |
| do { |
| struct xen_netif_tx_request dropped_tx = { 0 }; |
| |
| if (slots >= work_to_do) { |
| netdev_err(vif->dev, |
| "Asked for %d slots but exceeds this limit\n", |
| work_to_do); |
| xenvif_fatal_tx_err(vif); |
| return -ENODATA; |
| } |
| |
| /* This guest is really using too many slots and |
| * considered malicious. |
| */ |
| if (unlikely(slots >= fatal_skb_slots)) { |
| netdev_err(vif->dev, |
| "Malicious frontend using %d slots, threshold %u\n", |
| slots, fatal_skb_slots); |
| xenvif_fatal_tx_err(vif); |
| return -E2BIG; |
| } |
| |
| /* Xen network protocol had implicit dependency on |
| * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to |
| * the historical MAX_SKB_FRAGS value 18 to honor the |
| * same behavior as before. Any packet using more than |
| * 18 slots but less than fatal_skb_slots slots is |
| * dropped |
| */ |
| if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) { |
| if (net_ratelimit()) |
| netdev_dbg(vif->dev, |
| "Too many slots (%d) exceeding limit (%d), dropping packet\n", |
| slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| drop_err = -E2BIG; |
| } |
| |
| if (drop_err) |
| txp = &dropped_tx; |
| |
| memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots), |
| sizeof(*txp)); |
| |
| /* If the guest submitted a frame >= 64 KiB then |
| * first->size overflowed and following slots will |
| * appear to be larger than the frame. |
| * |
| * This cannot be fatal error as there are buggy |
| * frontends that do this. |
| * |
| * Consume all slots and drop the packet. |
| */ |
| if (!drop_err && txp->size > first->size) { |
| if (net_ratelimit()) |
| netdev_dbg(vif->dev, |
| "Invalid tx request, slot size %u > remaining size %u\n", |
| txp->size, first->size); |
| drop_err = -EIO; |
| } |
| |
| first->size -= txp->size; |
| slots++; |
| |
| if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) { |
| netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n", |
| txp->offset, txp->size); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| more_data = txp->flags & XEN_NETTXF_more_data; |
| |
| if (!drop_err) |
| txp++; |
| |
| } while (more_data); |
| |
| if (drop_err) { |
| xenvif_tx_err(vif, first, cons + slots); |
| return drop_err; |
| } |
| |
| return slots; |
| } |
| |
| static struct page *xenvif_alloc_page(struct xenvif *vif, |
| u16 pending_idx) |
| { |
| struct page *page; |
| |
| page = alloc_page(GFP_ATOMIC|__GFP_COLD); |
| if (!page) |
| return NULL; |
| vif->mmap_pages[pending_idx] = page; |
| |
| return page; |
| } |
| |
| static struct gnttab_copy *xenvif_get_requests(struct xenvif *vif, |
| struct sk_buff *skb, |
| struct xen_netif_tx_request *txp, |
| struct gnttab_copy *gop) |
| { |
| struct skb_shared_info *shinfo = skb_shinfo(skb); |
| skb_frag_t *frags = shinfo->frags; |
| u16 pending_idx = *((u16 *)skb->data); |
| u16 head_idx = 0; |
| int slot, start; |
| struct page *page; |
| pending_ring_idx_t index, start_idx = 0; |
| uint16_t dst_offset; |
| unsigned int nr_slots; |
| struct pending_tx_info *first = NULL; |
| |
| /* At this point shinfo->nr_frags is in fact the number of |
| * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX. |
| */ |
| nr_slots = shinfo->nr_frags; |
| |
| /* Skip first skb fragment if it is on same page as header fragment. */ |
| start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); |
| |
| /* Coalesce tx requests, at this point the packet passed in |
| * should be <= 64K. Any packets larger than 64K have been |
| * handled in xenvif_count_requests(). |
| */ |
| for (shinfo->nr_frags = slot = start; slot < nr_slots; |
| shinfo->nr_frags++) { |
| struct pending_tx_info *pending_tx_info = |
| vif->pending_tx_info; |
| |
| page = alloc_page(GFP_ATOMIC|__GFP_COLD); |
| if (!page) |
| goto err; |
| |
| dst_offset = 0; |
| first = NULL; |
| while (dst_offset < PAGE_SIZE && slot < nr_slots) { |
| gop->flags = GNTCOPY_source_gref; |
| |
| gop->source.u.ref = txp->gref; |
| gop->source.domid = vif->domid; |
| gop->source.offset = txp->offset; |
| |
| gop->dest.domid = DOMID_SELF; |
| |
| gop->dest.offset = dst_offset; |
| gop->dest.u.gmfn = virt_to_mfn(page_address(page)); |
| |
| if (dst_offset + txp->size > PAGE_SIZE) { |
| /* This page can only merge a portion |
| * of tx request. Do not increment any |
| * pointer / counter here. The txp |
| * will be dealt with in future |
| * rounds, eventually hitting the |
| * `else` branch. |
| */ |
| gop->len = PAGE_SIZE - dst_offset; |
| txp->offset += gop->len; |
| txp->size -= gop->len; |
| dst_offset += gop->len; /* quit loop */ |
| } else { |
| /* This tx request can be merged in the page */ |
| gop->len = txp->size; |
| dst_offset += gop->len; |
| |
| index = pending_index(vif->pending_cons++); |
| |
| pending_idx = vif->pending_ring[index]; |
| |
| memcpy(&pending_tx_info[pending_idx].req, txp, |
| sizeof(*txp)); |
| |
| /* Poison these fields, corresponding |
| * fields for head tx req will be set |
| * to correct values after the loop. |
| */ |
| vif->mmap_pages[pending_idx] = (void *)(~0UL); |
| pending_tx_info[pending_idx].head = |
| INVALID_PENDING_RING_IDX; |
| |
| if (!first) { |
| first = &pending_tx_info[pending_idx]; |
| start_idx = index; |
| head_idx = pending_idx; |
| } |
| |
| txp++; |
| slot++; |
| } |
| |
| gop++; |
| } |
| |
| first->req.offset = 0; |
| first->req.size = dst_offset; |
| first->head = start_idx; |
| vif->mmap_pages[head_idx] = page; |
| frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx); |
| } |
| |
| BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS); |
| |
| return gop; |
| err: |
| /* Unwind, freeing all pages and sending error responses. */ |
| while (shinfo->nr_frags-- > start) { |
| xenvif_idx_release(vif, |
| frag_get_pending_idx(&frags[shinfo->nr_frags]), |
| XEN_NETIF_RSP_ERROR); |
| } |
| /* The head too, if necessary. */ |
| if (start) |
| xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| |
| return NULL; |
| } |
| |
| static int xenvif_tx_check_gop(struct xenvif *vif, |
| struct sk_buff *skb, |
| struct gnttab_copy **gopp) |
| { |
| struct gnttab_copy *gop = *gopp; |
| u16 pending_idx = *((u16 *)skb->data); |
| struct skb_shared_info *shinfo = skb_shinfo(skb); |
| struct pending_tx_info *tx_info; |
| int nr_frags = shinfo->nr_frags; |
| int i, err, start; |
| u16 peek; /* peek into next tx request */ |
| |
| /* Check status of header. */ |
| err = gop->status; |
| if (unlikely(err)) |
| xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| |
| /* Skip first skb fragment if it is on same page as header fragment. */ |
| start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); |
| |
| for (i = start; i < nr_frags; i++) { |
| int j, newerr; |
| pending_ring_idx_t head; |
| |
| pending_idx = frag_get_pending_idx(&shinfo->frags[i]); |
| tx_info = &vif->pending_tx_info[pending_idx]; |
| head = tx_info->head; |
| |
| /* Check error status: if okay then remember grant handle. */ |
| do { |
| newerr = (++gop)->status; |
| if (newerr) |
| break; |
| peek = vif->pending_ring[pending_index(++head)]; |
| } while (!pending_tx_is_head(vif, peek)); |
| |
| if (likely(!newerr)) { |
| /* Had a previous error? Invalidate this fragment. */ |
| if (unlikely(err)) |
| xenvif_idx_release(vif, pending_idx, |
| XEN_NETIF_RSP_OKAY); |
| continue; |
| } |
| |
| /* Error on this fragment: respond to client with an error. */ |
| xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| |
| /* Not the first error? Preceding frags already invalidated. */ |
| if (err) |
| continue; |
| |
| /* First error: invalidate header and preceding fragments. */ |
| pending_idx = *((u16 *)skb->data); |
| xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); |
| for (j = start; j < i; j++) { |
| pending_idx = frag_get_pending_idx(&shinfo->frags[j]); |
| xenvif_idx_release(vif, pending_idx, |
| XEN_NETIF_RSP_OKAY); |
| } |
| |
| /* Remember the error: invalidate all subsequent fragments. */ |
| err = newerr; |
| } |
| |
| *gopp = gop + 1; |
| return err; |
| } |
| |
| static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb) |
| { |
| struct skb_shared_info *shinfo = skb_shinfo(skb); |
| int nr_frags = shinfo->nr_frags; |
| int i; |
| |
| for (i = 0; i < nr_frags; i++) { |
| skb_frag_t *frag = shinfo->frags + i; |
| struct xen_netif_tx_request *txp; |
| struct page *page; |
| u16 pending_idx; |
| |
| pending_idx = frag_get_pending_idx(frag); |
| |
| txp = &vif->pending_tx_info[pending_idx].req; |
| page = virt_to_page(idx_to_kaddr(vif, pending_idx)); |
| __skb_fill_page_desc(skb, i, page, txp->offset, txp->size); |
| skb->len += txp->size; |
| skb->data_len += txp->size; |
| skb->truesize += txp->size; |
| |
| /* Take an extra reference to offset xenvif_idx_release */ |
| get_page(vif->mmap_pages[pending_idx]); |
| xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); |
| } |
| } |
| |
| static int xenvif_get_extras(struct xenvif *vif, |
| struct xen_netif_extra_info *extras, |
| int work_to_do) |
| { |
| struct xen_netif_extra_info extra; |
| RING_IDX cons = vif->tx.req_cons; |
| |
| do { |
| if (unlikely(work_to_do-- <= 0)) { |
| netdev_err(vif->dev, "Missing extra info\n"); |
| xenvif_fatal_tx_err(vif); |
| return -EBADR; |
| } |
| |
| memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons), |
| sizeof(extra)); |
| if (unlikely(!extra.type || |
| extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { |
| vif->tx.req_cons = ++cons; |
| netdev_err(vif->dev, |
| "Invalid extra type: %d\n", extra.type); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); |
| vif->tx.req_cons = ++cons; |
| } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); |
| |
| return work_to_do; |
| } |
| |
| static int xenvif_set_skb_gso(struct xenvif *vif, |
| struct sk_buff *skb, |
| struct xen_netif_extra_info *gso) |
| { |
| if (!gso->u.gso.size) { |
| netdev_err(vif->dev, "GSO size must not be zero.\n"); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| /* Currently only TCPv4 S.O. is supported. */ |
| if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) { |
| netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| skb_shinfo(skb)->gso_size = gso->u.gso.size; |
| skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| |
| /* Header must be checked, and gso_segs computed. */ |
| skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| skb_shinfo(skb)->gso_segs = 0; |
| |
| return 0; |
| } |
| |
| static inline void maybe_pull_tail(struct sk_buff *skb, unsigned int len) |
| { |
| if (skb_is_nonlinear(skb) && skb_headlen(skb) < len) { |
| /* If we need to pullup then pullup to the max, so we |
| * won't need to do it again. |
| */ |
| int target = min_t(int, skb->len, MAX_TCP_HEADER); |
| __pskb_pull_tail(skb, target - skb_headlen(skb)); |
| } |
| } |
| |
| static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb, |
| int recalculate_partial_csum) |
| { |
| struct iphdr *iph = (void *)skb->data; |
| unsigned int header_size; |
| unsigned int off; |
| int err = -EPROTO; |
| |
| off = sizeof(struct iphdr); |
| |
| header_size = skb->network_header + off + MAX_IPOPTLEN; |
| maybe_pull_tail(skb, header_size); |
| |
| off = iph->ihl * 4; |
| |
| switch (iph->protocol) { |
| case IPPROTO_TCP: |
| if (!skb_partial_csum_set(skb, off, |
| offsetof(struct tcphdr, check))) |
| goto out; |
| |
| if (recalculate_partial_csum) { |
| struct tcphdr *tcph = tcp_hdr(skb); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct tcphdr); |
| maybe_pull_tail(skb, header_size); |
| |
| tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, |
| skb->len - off, |
| IPPROTO_TCP, 0); |
| } |
| break; |
| case IPPROTO_UDP: |
| if (!skb_partial_csum_set(skb, off, |
| offsetof(struct udphdr, check))) |
| goto out; |
| |
| if (recalculate_partial_csum) { |
| struct udphdr *udph = udp_hdr(skb); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct udphdr); |
| maybe_pull_tail(skb, header_size); |
| |
| udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, |
| skb->len - off, |
| IPPROTO_UDP, 0); |
| } |
| break; |
| default: |
| if (net_ratelimit()) |
| netdev_err(vif->dev, |
| "Attempting to checksum a non-TCP/UDP packet, " |
| "dropping a protocol %d packet\n", |
| iph->protocol); |
| goto out; |
| } |
| |
| err = 0; |
| |
| out: |
| return err; |
| } |
| |
| static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb, |
| int recalculate_partial_csum) |
| { |
| int err = -EPROTO; |
| struct ipv6hdr *ipv6h = (void *)skb->data; |
| u8 nexthdr; |
| unsigned int header_size; |
| unsigned int off; |
| bool fragment; |
| bool done; |
| |
| done = false; |
| |
| off = sizeof(struct ipv6hdr); |
| |
| header_size = skb->network_header + off; |
| maybe_pull_tail(skb, header_size); |
| |
| nexthdr = ipv6h->nexthdr; |
| |
| while ((off <= sizeof(struct ipv6hdr) + ntohs(ipv6h->payload_len)) && |
| !done) { |
| switch (nexthdr) { |
| case IPPROTO_DSTOPTS: |
| case IPPROTO_HOPOPTS: |
| case IPPROTO_ROUTING: { |
| struct ipv6_opt_hdr *hp = (void *)(skb->data + off); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct ipv6_opt_hdr); |
| maybe_pull_tail(skb, header_size); |
| |
| nexthdr = hp->nexthdr; |
| off += ipv6_optlen(hp); |
| break; |
| } |
| case IPPROTO_AH: { |
| struct ip_auth_hdr *hp = (void *)(skb->data + off); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct ip_auth_hdr); |
| maybe_pull_tail(skb, header_size); |
| |
| nexthdr = hp->nexthdr; |
| off += (hp->hdrlen+2)<<2; |
| break; |
| } |
| case IPPROTO_FRAGMENT: |
| fragment = true; |
| /* fall through */ |
| default: |
| done = true; |
| break; |
| } |
| } |
| |
| if (!done) { |
| if (net_ratelimit()) |
| netdev_err(vif->dev, "Failed to parse packet header\n"); |
| goto out; |
| } |
| |
| if (fragment) { |
| if (net_ratelimit()) |
| netdev_err(vif->dev, "Packet is a fragment!\n"); |
| goto out; |
| } |
| |
| switch (nexthdr) { |
| case IPPROTO_TCP: |
| if (!skb_partial_csum_set(skb, off, |
| offsetof(struct tcphdr, check))) |
| goto out; |
| |
| if (recalculate_partial_csum) { |
| struct tcphdr *tcph = tcp_hdr(skb); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct tcphdr); |
| maybe_pull_tail(skb, header_size); |
| |
| tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, |
| &ipv6h->daddr, |
| skb->len - off, |
| IPPROTO_TCP, 0); |
| } |
| break; |
| case IPPROTO_UDP: |
| if (!skb_partial_csum_set(skb, off, |
| offsetof(struct udphdr, check))) |
| goto out; |
| |
| if (recalculate_partial_csum) { |
| struct udphdr *udph = udp_hdr(skb); |
| |
| header_size = skb->network_header + |
| off + |
| sizeof(struct udphdr); |
| maybe_pull_tail(skb, header_size); |
| |
| udph->check = ~csum_ipv6_magic(&ipv6h->saddr, |
| &ipv6h->daddr, |
| skb->len - off, |
| IPPROTO_UDP, 0); |
| } |
| break; |
| default: |
| if (net_ratelimit()) |
| netdev_err(vif->dev, |
| "Attempting to checksum a non-TCP/UDP packet, " |
| "dropping a protocol %d packet\n", |
| nexthdr); |
| goto out; |
| } |
| |
| err = 0; |
| |
| out: |
| return err; |
| } |
| |
| static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) |
| { |
| int err = -EPROTO; |
| int recalculate_partial_csum = 0; |
| |
| /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy |
| * peers can fail to set NETRXF_csum_blank when sending a GSO |
| * frame. In this case force the SKB to CHECKSUM_PARTIAL and |
| * recalculate the partial checksum. |
| */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { |
| vif->rx_gso_checksum_fixup++; |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| recalculate_partial_csum = 1; |
| } |
| |
| /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL) |
| return 0; |
| |
| if (skb->protocol == htons(ETH_P_IP)) |
| err = checksum_setup_ip(vif, skb, recalculate_partial_csum); |
| else if (skb->protocol == htons(ETH_P_IPV6)) |
| err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum); |
| |
| return err; |
| } |
| |
| static bool tx_credit_exceeded(struct xenvif *vif, unsigned size) |
| { |
| unsigned long now = jiffies; |
| unsigned long next_credit = |
| vif->credit_timeout.expires + |
| msecs_to_jiffies(vif->credit_usec / 1000); |
| |
| /* Timer could already be pending in rare cases. */ |
| if (timer_pending(&vif->credit_timeout)) |
| return true; |
| |
| /* Passed the point where we can replenish credit? */ |
| if (time_after_eq(now, next_credit)) { |
| vif->credit_timeout.expires = now; |
| tx_add_credit(vif); |
| } |
| |
| /* Still too big to send right now? Set a callback. */ |
| if (size > vif->remaining_credit) { |
| vif->credit_timeout.data = |
| (unsigned long)vif; |
| vif->credit_timeout.function = |
| tx_credit_callback; |
| mod_timer(&vif->credit_timeout, |
| next_credit); |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static unsigned xenvif_tx_build_gops(struct xenvif *vif) |
| { |
| struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop; |
| struct sk_buff *skb; |
| int ret; |
| |
| while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX |
| < MAX_PENDING_REQS)) { |
| struct xen_netif_tx_request txreq; |
| struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX]; |
| struct page *page; |
| struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; |
| u16 pending_idx; |
| RING_IDX idx; |
| int work_to_do; |
| unsigned int data_len; |
| pending_ring_idx_t index; |
| |
| if (vif->tx.sring->req_prod - vif->tx.req_cons > |
| XEN_NETIF_TX_RING_SIZE) { |
| netdev_err(vif->dev, |
| "Impossible number of requests. " |
| "req_prod %d, req_cons %d, size %ld\n", |
| vif->tx.sring->req_prod, vif->tx.req_cons, |
| XEN_NETIF_TX_RING_SIZE); |
| xenvif_fatal_tx_err(vif); |
| continue; |
| } |
| |
| RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, work_to_do); |
| if (!work_to_do) |
| break; |
| |
| idx = vif->tx.req_cons; |
| rmb(); /* Ensure that we see the request before we copy it. */ |
| memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq)); |
| |
| /* Credit-based scheduling. */ |
| if (txreq.size > vif->remaining_credit && |
| tx_credit_exceeded(vif, txreq.size)) |
| break; |
| |
| vif->remaining_credit -= txreq.size; |
| |
| work_to_do--; |
| vif->tx.req_cons = ++idx; |
| |
| memset(extras, 0, sizeof(extras)); |
| if (txreq.flags & XEN_NETTXF_extra_info) { |
| work_to_do = xenvif_get_extras(vif, extras, |
| work_to_do); |
| idx = vif->tx.req_cons; |
| if (unlikely(work_to_do < 0)) |
| break; |
| } |
| |
| ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do); |
| if (unlikely(ret < 0)) |
| break; |
| |
| idx += ret; |
| |
| if (unlikely(txreq.size < ETH_HLEN)) { |
| netdev_dbg(vif->dev, |
| "Bad packet size: %d\n", txreq.size); |
| xenvif_tx_err(vif, &txreq, idx); |
| break; |
| } |
| |
| /* No crossing a page as the payload mustn't fragment. */ |
| if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) { |
| netdev_err(vif->dev, |
| "txreq.offset: %x, size: %u, end: %lu\n", |
| txreq.offset, txreq.size, |
| (txreq.offset&~PAGE_MASK) + txreq.size); |
| xenvif_fatal_tx_err(vif); |
| break; |
| } |
| |
| index = pending_index(vif->pending_cons); |
| pending_idx = vif->pending_ring[index]; |
| |
| data_len = (txreq.size > PKT_PROT_LEN && |
| ret < XEN_NETBK_LEGACY_SLOTS_MAX) ? |
| PKT_PROT_LEN : txreq.size; |
| |
| skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN, |
| GFP_ATOMIC | __GFP_NOWARN); |
| if (unlikely(skb == NULL)) { |
| netdev_dbg(vif->dev, |
| "Can't allocate a skb in start_xmit.\n"); |
| xenvif_tx_err(vif, &txreq, idx); |
| break; |
| } |
| |
| /* Packets passed to netif_rx() must have some headroom. */ |
| skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); |
| |
| if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { |
| struct xen_netif_extra_info *gso; |
| gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; |
| |
| if (xenvif_set_skb_gso(vif, skb, gso)) { |
| /* Failure in xenvif_set_skb_gso is fatal. */ |
| kfree_skb(skb); |
| break; |
| } |
| } |
| |
| /* XXX could copy straight to head */ |
| page = xenvif_alloc_page(vif, pending_idx); |
| if (!page) { |
| kfree_skb(skb); |
| xenvif_tx_err(vif, &txreq, idx); |
| break; |
| } |
| |
| gop->source.u.ref = txreq.gref; |
| gop->source.domid = vif->domid; |
| gop->source.offset = txreq.offset; |
| |
| gop->dest.u.gmfn = virt_to_mfn(page_address(page)); |
| gop->dest.domid = DOMID_SELF; |
| gop->dest.offset = txreq.offset; |
| |
| gop->len = txreq.size; |
| gop->flags = GNTCOPY_source_gref; |
| |
| gop++; |
| |
| memcpy(&vif->pending_tx_info[pending_idx].req, |
| &txreq, sizeof(txreq)); |
| vif->pending_tx_info[pending_idx].head = index; |
| *((u16 *)skb->data) = pending_idx; |
| |
| __skb_put(skb, data_len); |
| |
| skb_shinfo(skb)->nr_frags = ret; |
| if (data_len < txreq.size) { |
| skb_shinfo(skb)->nr_frags++; |
| frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| pending_idx); |
| } else { |
| frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| INVALID_PENDING_IDX); |
| } |
| |
| vif->pending_cons++; |
| |
| request_gop = xenvif_get_requests(vif, skb, txfrags, gop); |
| if (request_gop == NULL) { |
| kfree_skb(skb); |
| xenvif_tx_err(vif, &txreq, idx); |
| break; |
| } |
| gop = request_gop; |
| |
| __skb_queue_tail(&vif->tx_queue, skb); |
| |
| vif->tx.req_cons = idx; |
| |
| if ((gop-vif->tx_copy_ops) >= ARRAY_SIZE(vif->tx_copy_ops)) |
| break; |
| } |
| |
| return gop - vif->tx_copy_ops; |
| } |
| |
| |
| static int xenvif_tx_submit(struct xenvif *vif, int budget) |
| { |
| struct gnttab_copy *gop = vif->tx_copy_ops; |
| struct sk_buff *skb; |
| int work_done = 0; |
| |
| while (work_done < budget && |
| (skb = __skb_dequeue(&vif->tx_queue)) != NULL) { |
| struct xen_netif_tx_request *txp; |
| u16 pending_idx; |
| unsigned data_len; |
| |
| pending_idx = *((u16 *)skb->data); |
| txp = &vif->pending_tx_info[pending_idx].req; |
| |
| /* Check the remap error code. */ |
| if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) { |
| netdev_dbg(vif->dev, "netback grant failed.\n"); |
| skb_shinfo(skb)->nr_frags = 0; |
| kfree_skb(skb); |
| continue; |
| } |
| |
| data_len = skb->len; |
| memcpy(skb->data, |
| (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset), |
| data_len); |
| if (data_len < txp->size) { |
| /* Append the packet payload as a fragment. */ |
| txp->offset += data_len; |
| txp->size -= data_len; |
| } else { |
| /* Schedule a response immediately. */ |
| xenvif_idx_release(vif, pending_idx, |
| XEN_NETIF_RSP_OKAY); |
| } |
| |
| if (txp->flags & XEN_NETTXF_csum_blank) |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| else if (txp->flags & XEN_NETTXF_data_validated) |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| xenvif_fill_frags(vif, skb); |
| |
| if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) { |
| int target = min_t(int, skb->len, PKT_PROT_LEN); |
| __pskb_pull_tail(skb, target - skb_headlen(skb)); |
| } |
| |
| skb->dev = vif->dev; |
| skb->protocol = eth_type_trans(skb, skb->dev); |
| skb_reset_network_header(skb); |
| |
| if (checksum_setup(vif, skb)) { |
| netdev_dbg(vif->dev, |
| "Can't setup checksum in net_tx_action\n"); |
| kfree_skb(skb); |
| continue; |
| } |
| |
| skb_probe_transport_header(skb, 0); |
| |
| vif->dev->stats.rx_bytes += skb->len; |
| vif->dev->stats.rx_packets++; |
| |
| work_done++; |
| |
| netif_receive_skb(skb); |
| } |
| |
| return work_done; |
| } |
| |
| /* Called after netfront has transmitted */ |
| int xenvif_tx_action(struct xenvif *vif, int budget) |
| { |
| unsigned nr_gops; |
| int work_done; |
| |
| if (unlikely(!tx_work_todo(vif))) |
| return 0; |
| |
| nr_gops = xenvif_tx_build_gops(vif); |
| |
| if (nr_gops == 0) |
| return 0; |
| |
| gnttab_batch_copy(vif->tx_copy_ops, nr_gops); |
| |
| work_done = xenvif_tx_submit(vif, nr_gops); |
| |
| return work_done; |
| } |
| |
| static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, |
| u8 status) |
| { |
| struct pending_tx_info *pending_tx_info; |
| pending_ring_idx_t head; |
| u16 peek; /* peek into next tx request */ |
| |
| BUG_ON(vif->mmap_pages[pending_idx] == (void *)(~0UL)); |
| |
| /* Already complete? */ |
| if (vif->mmap_pages[pending_idx] == NULL) |
| return; |
| |
| pending_tx_info = &vif->pending_tx_info[pending_idx]; |
| |
| head = pending_tx_info->head; |
| |
| BUG_ON(!pending_tx_is_head(vif, head)); |
| BUG_ON(vif->pending_ring[pending_index(head)] != pending_idx); |
| |
| do { |
| pending_ring_idx_t index; |
| pending_ring_idx_t idx = pending_index(head); |
| u16 info_idx = vif->pending_ring[idx]; |
| |
| pending_tx_info = &vif->pending_tx_info[info_idx]; |
| make_tx_response(vif, &pending_tx_info->req, status); |
| |
| /* Setting any number other than |
| * INVALID_PENDING_RING_IDX indicates this slot is |
| * starting a new packet / ending a previous packet. |
| */ |
| pending_tx_info->head = 0; |
| |
| index = pending_index(vif->pending_prod++); |
| vif->pending_ring[index] = vif->pending_ring[info_idx]; |
| |
| peek = vif->pending_ring[pending_index(++head)]; |
| |
| } while (!pending_tx_is_head(vif, peek)); |
| |
| put_page(vif->mmap_pages[pending_idx]); |
| vif->mmap_pages[pending_idx] = NULL; |
| } |
| |
| |
| static void make_tx_response(struct xenvif *vif, |
| struct xen_netif_tx_request *txp, |
| s8 st) |
| { |
| RING_IDX i = vif->tx.rsp_prod_pvt; |
| struct xen_netif_tx_response *resp; |
| int notify; |
| |
| resp = RING_GET_RESPONSE(&vif->tx, i); |
| resp->id = txp->id; |
| resp->status = st; |
| |
| if (txp->flags & XEN_NETTXF_extra_info) |
| RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL; |
| |
| vif->tx.rsp_prod_pvt = ++i; |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify); |
| if (notify) |
| notify_remote_via_irq(vif->tx_irq); |
| } |
| |
| static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, |
| u16 id, |
| s8 st, |
| u16 offset, |
| u16 size, |
| u16 flags) |
| { |
| RING_IDX i = vif->rx.rsp_prod_pvt; |
| struct xen_netif_rx_response *resp; |
| |
| resp = RING_GET_RESPONSE(&vif->rx, i); |
| resp->offset = offset; |
| resp->flags = flags; |
| resp->id = id; |
| resp->status = (s16)size; |
| if (st < 0) |
| resp->status = (s16)st; |
| |
| vif->rx.rsp_prod_pvt = ++i; |
| |
| return resp; |
| } |
| |
| static inline int rx_work_todo(struct xenvif *vif) |
| { |
| return !skb_queue_empty(&vif->rx_queue); |
| } |
| |
| static inline int tx_work_todo(struct xenvif *vif) |
| { |
| |
| if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) && |
| (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX |
| < MAX_PENDING_REQS)) |
| return 1; |
| |
| return 0; |
| } |
| |
| void xenvif_unmap_frontend_rings(struct xenvif *vif) |
| { |
| if (vif->tx.sring) |
| xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), |
| vif->tx.sring); |
| if (vif->rx.sring) |
| xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), |
| vif->rx.sring); |
| } |
| |
| int xenvif_map_frontend_rings(struct xenvif *vif, |
| grant_ref_t tx_ring_ref, |
| grant_ref_t rx_ring_ref) |
| { |
| void *addr; |
| struct xen_netif_tx_sring *txs; |
| struct xen_netif_rx_sring *rxs; |
| |
| int err = -ENOMEM; |
| |
| err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), |
| tx_ring_ref, &addr); |
| if (err) |
| goto err; |
| |
| txs = (struct xen_netif_tx_sring *)addr; |
| BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE); |
| |
| err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), |
| rx_ring_ref, &addr); |
| if (err) |
| goto err; |
| |
| rxs = (struct xen_netif_rx_sring *)addr; |
| BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE); |
| |
| vif->rx_req_cons_peek = 0; |
| |
| return 0; |
| |
| err: |
| xenvif_unmap_frontend_rings(vif); |
| return err; |
| } |
| |
| int xenvif_kthread(void *data) |
| { |
| struct xenvif *vif = data; |
| |
| while (!kthread_should_stop()) { |
| wait_event_interruptible(vif->wq, |
| rx_work_todo(vif) || |
| kthread_should_stop()); |
| if (kthread_should_stop()) |
| break; |
| |
| if (rx_work_todo(vif)) |
| xenvif_rx_action(vif); |
| |
| cond_resched(); |
| } |
| |
| return 0; |
| } |
| |
| static int __init netback_init(void) |
| { |
| int rc = 0; |
| |
| if (!xen_domain()) |
| return -ENODEV; |
| |
| if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) { |
| pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n", |
| fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX; |
| } |
| |
| rc = xenvif_xenbus_init(); |
| if (rc) |
| goto failed_init; |
| |
| return 0; |
| |
| failed_init: |
| return rc; |
| } |
| |
| module_init(netback_init); |
| |
| static void __exit netback_fini(void) |
| { |
| xenvif_xenbus_fini(); |
| } |
| module_exit(netback_fini); |
| |
| MODULE_LICENSE("Dual BSD/GPL"); |
| MODULE_ALIAS("xen-backend:vif"); |