diff options
Diffstat (limited to 'usr/src/cmd/bhyve/net_backends.c')
| -rw-r--r-- | usr/src/cmd/bhyve/net_backends.c | 807 |
1 files changed, 807 insertions, 0 deletions
diff --git a/usr/src/cmd/bhyve/net_backends.c b/usr/src/cmd/bhyve/net_backends.c new file mode 100644 index 0000000000..88afaca4b1 --- /dev/null +++ b/usr/src/cmd/bhyve/net_backends.c @@ -0,0 +1,807 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2019 Vincenzo Maffione <vmaffione@FreeBSD.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, + * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE + * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $FreeBSD$ + */ + +/* + * This file implements multiple network backends (tap, netmap, ...), + * to be used by network frontends such as virtio-net and e1000. + * The API to access the backend (e.g. send/receive packets, negotiate + * features) is exported by net_backends.h. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> /* u_short etc */ +#ifndef WITHOUT_CAPSICUM +#include <sys/capsicum.h> +#endif +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/uio.h> + +#include <net/if.h> +#include <net/netmap.h> +#include <net/netmap_virt.h> +#define NETMAP_WITH_LIBS +#include <net/netmap_user.h> + +#ifndef WITHOUT_CAPSICUM +#include <capsicum_helpers.h> +#endif +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <unistd.h> +#include <sysexits.h> +#include <assert.h> +#include <pthread.h> +#include <pthread_np.h> +#include <poll.h> +#include <assert.h> + + +#include "iov.h" +#include "mevent.h" +#include "net_backends.h" + +#include <sys/linker_set.h> + +/* + * Each network backend registers a set of function pointers that are + * used to implement the net backends API. + * This might need to be exposed if we implement backends in separate files. + */ +struct net_backend { + const char *prefix; /* prefix matching this backend */ + + /* + * Routines used to initialize and cleanup the resources needed + * by a backend. The cleanup function is used internally, + * and should not be called by the frontend. + */ + int (*init)(struct net_backend *be, const char *devname, + net_be_rxeof_t cb, void *param); + void (*cleanup)(struct net_backend *be); + + /* + * Called to serve a guest transmit request. The scatter-gather + * vector provided by the caller has 'iovcnt' elements and contains + * the packet to send. + */ + ssize_t (*send)(struct net_backend *be, struct iovec *iov, int iovcnt); + + /* + * Called to receive a packet from the backend. When the function + * returns a positive value 'len', the scatter-gather vector + * provided by the caller contains a packet with such length. + * The function returns 0 if the backend doesn't have a new packet to + * receive. + */ + ssize_t (*recv)(struct net_backend *be, struct iovec *iov, int iovcnt); + + /* + * Ask the backend for the virtio-net features it is able to + * support. Possible features are TSO, UFO and checksum offloading + * in both rx and tx direction and for both IPv4 and IPv6. + */ + uint64_t (*get_cap)(struct net_backend *be); + + /* + * Tell the backend to enable/disable the specified virtio-net + * features (capabilities). + */ + int (*set_cap)(struct net_backend *be, uint64_t features, + unsigned int vnet_hdr_len); + + struct pci_vtnet_softc *sc; + int fd; + + /* + * Length of the virtio-net header used by the backend and the + * frontend, respectively. A zero value means that the header + * is not used. + */ + unsigned int be_vnet_hdr_len; + unsigned int fe_vnet_hdr_len; + + /* Size of backend-specific private data. */ + size_t priv_size; + + /* Room for backend-specific data. */ + char opaque[0]; +}; + +SET_DECLARE(net_backend_set, struct net_backend); + +#define VNET_HDR_LEN sizeof(struct virtio_net_rxhdr) + +#define WPRINTF(params) printf params + +/* + * The tap backend + */ + +struct tap_priv { + struct mevent *mevp; +}; + +static void +tap_cleanup(struct net_backend *be) +{ + struct tap_priv *priv = (struct tap_priv *)be->opaque; + + if (priv->mevp) { + mevent_delete(priv->mevp); + } + if (be->fd != -1) { + close(be->fd); + be->fd = -1; + } +} + +static int +tap_init(struct net_backend *be, const char *devname, + net_be_rxeof_t cb, void *param) +{ + struct tap_priv *priv = (struct tap_priv *)be->opaque; + char tbuf[80]; + int opt = 1; +#ifndef WITHOUT_CAPSICUM + cap_rights_t rights; +#endif + + if (cb == NULL) { + WPRINTF(("TAP backend requires non-NULL callback\n")); + return (-1); + } + + strcpy(tbuf, "/dev/"); + strlcat(tbuf, devname, sizeof(tbuf)); + + be->fd = open(tbuf, O_RDWR); + if (be->fd == -1) { + WPRINTF(("open of tap device %s failed\n", tbuf)); + goto error; + } + + /* + * Set non-blocking and register for read + * notifications with the event loop + */ + if (ioctl(be->fd, FIONBIO, &opt) < 0) { + WPRINTF(("tap device O_NONBLOCK failed\n")); + goto error; + } + +#ifndef WITHOUT_CAPSICUM + cap_rights_init(&rights, CAP_EVENT, CAP_READ, CAP_WRITE); + if (caph_rights_limit(be->fd, &rights) == -1) + errx(EX_OSERR, "Unable to apply rights for sandbox"); +#endif + + priv->mevp = mevent_add(be->fd, EVF_READ, cb, param); + if (priv->mevp == NULL) { + WPRINTF(("Could not register event\n")); + goto error; + } + + return (0); + +error: + tap_cleanup(be); + return (-1); +} + +/* + * Called to send a buffer chain out to the tap device + */ +static ssize_t +tap_send(struct net_backend *be, struct iovec *iov, int iovcnt) +{ + return (writev(be->fd, iov, iovcnt)); +} + +static ssize_t +tap_recv(struct net_backend *be, struct iovec *iov, int iovcnt) +{ + ssize_t ret; + + /* Should never be called without a valid tap fd */ + assert(be->fd != -1); + + ret = readv(be->fd, iov, iovcnt); + + if (ret < 0 && errno == EWOULDBLOCK) { + return (0); + } + + return (ret); +} + +static uint64_t +tap_get_cap(struct net_backend *be) +{ + + return (0); /* no capabilities for now */ +} + +static int +tap_set_cap(struct net_backend *be, uint64_t features, + unsigned vnet_hdr_len) +{ + + return ((features || vnet_hdr_len) ? -1 : 0); +} + +static struct net_backend tap_backend = { + .prefix = "tap", + .priv_size = sizeof(struct tap_priv), + .init = tap_init, + .cleanup = tap_cleanup, + .send = tap_send, + .recv = tap_recv, + .get_cap = tap_get_cap, + .set_cap = tap_set_cap, +}; + +/* A clone of the tap backend, with a different prefix. */ +static struct net_backend vmnet_backend = { + .prefix = "vmnet", + .priv_size = sizeof(struct tap_priv), + .init = tap_init, + .cleanup = tap_cleanup, + .send = tap_send, + .recv = tap_recv, + .get_cap = tap_get_cap, + .set_cap = tap_set_cap, +}; + +DATA_SET(net_backend_set, tap_backend); +DATA_SET(net_backend_set, vmnet_backend); + +/* + * The netmap backend + */ + +/* The virtio-net features supported by netmap. */ +#define NETMAP_FEATURES (VIRTIO_NET_F_CSUM | VIRTIO_NET_F_HOST_TSO4 | \ + VIRTIO_NET_F_HOST_TSO6 | VIRTIO_NET_F_HOST_UFO | \ + VIRTIO_NET_F_GUEST_CSUM | VIRTIO_NET_F_GUEST_TSO4 | \ + VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_UFO) + +struct netmap_priv { + char ifname[IFNAMSIZ]; + struct nm_desc *nmd; + uint16_t memid; + struct netmap_ring *rx; + struct netmap_ring *tx; + struct mevent *mevp; + net_be_rxeof_t cb; + void *cb_param; +}; + +static void +nmreq_init(struct nmreq *req, char *ifname) +{ + + memset(req, 0, sizeof(*req)); + strlcpy(req->nr_name, ifname, sizeof(req->nr_name)); + req->nr_version = NETMAP_API; +} + +static int +netmap_set_vnet_hdr_len(struct net_backend *be, int vnet_hdr_len) +{ + int err; + struct nmreq req; + struct netmap_priv *priv = (struct netmap_priv *)be->opaque; + + nmreq_init(&req, priv->ifname); + req.nr_cmd = NETMAP_BDG_VNET_HDR; + req.nr_arg1 = vnet_hdr_len; + err = ioctl(be->fd, NIOCREGIF, &req); + if (err) { + WPRINTF(("Unable to set vnet header length %d\n", + vnet_hdr_len)); + return (err); + } + + be->be_vnet_hdr_len = vnet_hdr_len; + + return (0); +} + +static int +netmap_has_vnet_hdr_len(struct net_backend *be, unsigned vnet_hdr_len) +{ + int prev_hdr_len = be->be_vnet_hdr_len; + int ret; + + if (vnet_hdr_len == prev_hdr_len) { + return (1); + } + + ret = netmap_set_vnet_hdr_len(be, vnet_hdr_len); + if (ret) { + return (0); + } + + netmap_set_vnet_hdr_len(be, prev_hdr_len); + + return (1); +} + +static uint64_t +netmap_get_cap(struct net_backend *be) +{ + + return (netmap_has_vnet_hdr_len(be, VNET_HDR_LEN) ? + NETMAP_FEATURES : 0); +} + +static int +netmap_set_cap(struct net_backend *be, uint64_t features, + unsigned vnet_hdr_len) +{ + + return (netmap_set_vnet_hdr_len(be, vnet_hdr_len)); +} + +static int +netmap_init(struct net_backend *be, const char *devname, + net_be_rxeof_t cb, void *param) +{ + struct netmap_priv *priv = (struct netmap_priv *)be->opaque; + + strlcpy(priv->ifname, devname, sizeof(priv->ifname)); + priv->ifname[sizeof(priv->ifname) - 1] = '\0'; + + priv->nmd = nm_open(priv->ifname, NULL, NETMAP_NO_TX_POLL, NULL); + if (priv->nmd == NULL) { + WPRINTF(("Unable to nm_open(): interface '%s', errno (%s)\n", + devname, strerror(errno))); + free(priv); + return (-1); + } + + priv->memid = priv->nmd->req.nr_arg2; + priv->tx = NETMAP_TXRING(priv->nmd->nifp, 0); + priv->rx = NETMAP_RXRING(priv->nmd->nifp, 0); + priv->cb = cb; + priv->cb_param = param; + be->fd = priv->nmd->fd; + + priv->mevp = mevent_add(be->fd, EVF_READ, cb, param); + if (priv->mevp == NULL) { + WPRINTF(("Could not register event\n")); + return (-1); + } + + return (0); +} + +static void +netmap_cleanup(struct net_backend *be) +{ + struct netmap_priv *priv = (struct netmap_priv *)be->opaque; + + if (priv->mevp) { + mevent_delete(priv->mevp); + } + if (priv->nmd) { + nm_close(priv->nmd); + } + be->fd = -1; +} + +static ssize_t +netmap_send(struct net_backend *be, struct iovec *iov, + int iovcnt) +{ + struct netmap_priv *priv = (struct netmap_priv *)be->opaque; + struct netmap_ring *ring; + ssize_t totlen = 0; + int nm_buf_size; + int nm_buf_len; + uint32_t head; + void *nm_buf; + int j; + + ring = priv->tx; + head = ring->head; + if (head == ring->tail) { + WPRINTF(("No space, drop %zu bytes\n", count_iov(iov, iovcnt))); + goto txsync; + } + nm_buf = NETMAP_BUF(ring, ring->slot[head].buf_idx); + nm_buf_size = ring->nr_buf_size; + nm_buf_len = 0; + + for (j = 0; j < iovcnt; j++) { + int iov_frag_size = iov[j].iov_len; + void *iov_frag_buf = iov[j].iov_base; + + totlen += iov_frag_size; + + /* + * Split each iovec fragment over more netmap slots, if + * necessary. + */ + for (;;) { + int copylen; + + copylen = iov_frag_size < nm_buf_size ? iov_frag_size : nm_buf_size; + memcpy(nm_buf, iov_frag_buf, copylen); + + iov_frag_buf += copylen; + iov_frag_size -= copylen; + nm_buf += copylen; + nm_buf_size -= copylen; + nm_buf_len += copylen; + + if (iov_frag_size == 0) { + break; + } + + ring->slot[head].len = nm_buf_len; + ring->slot[head].flags = NS_MOREFRAG; + head = nm_ring_next(ring, head); + if (head == ring->tail) { + /* + * We ran out of netmap slots while + * splitting the iovec fragments. + */ + WPRINTF(("No space, drop %zu bytes\n", + count_iov(iov, iovcnt))); + goto txsync; + } + nm_buf = NETMAP_BUF(ring, ring->slot[head].buf_idx); + nm_buf_size = ring->nr_buf_size; + nm_buf_len = 0; + } + } + + /* Complete the last slot, which must not have NS_MOREFRAG set. */ + ring->slot[head].len = nm_buf_len; + ring->slot[head].flags = 0; + head = nm_ring_next(ring, head); + + /* Now update ring->head and ring->cur. */ + ring->head = ring->cur = head; +txsync: + ioctl(be->fd, NIOCTXSYNC, NULL); + + return (totlen); +} + +static ssize_t +netmap_recv(struct net_backend *be, struct iovec *iov, int iovcnt) +{ + struct netmap_priv *priv = (struct netmap_priv *)be->opaque; + struct netmap_slot *slot = NULL; + struct netmap_ring *ring; + void *iov_frag_buf; + int iov_frag_size; + ssize_t totlen = 0; + uint32_t head; + + assert(iovcnt); + + ring = priv->rx; + head = ring->head; + iov_frag_buf = iov->iov_base; + iov_frag_size = iov->iov_len; + + do { + int nm_buf_len; + void *nm_buf; + + if (head == ring->tail) { + return (0); + } + + slot = ring->slot + head; + nm_buf = NETMAP_BUF(ring, slot->buf_idx); + nm_buf_len = slot->len; + + for (;;) { + int copylen = nm_buf_len < iov_frag_size ? + nm_buf_len : iov_frag_size; + + memcpy(iov_frag_buf, nm_buf, copylen); + nm_buf += copylen; + nm_buf_len -= copylen; + iov_frag_buf += copylen; + iov_frag_size -= copylen; + totlen += copylen; + + if (nm_buf_len == 0) { + break; + } + + iov++; + iovcnt--; + if (iovcnt == 0) { + /* No space to receive. */ + WPRINTF(("Short iov, drop %zd bytes\n", + totlen)); + return (-ENOSPC); + } + iov_frag_buf = iov->iov_base; + iov_frag_size = iov->iov_len; + } + + head = nm_ring_next(ring, head); + + } while (slot->flags & NS_MOREFRAG); + + /* Release slots to netmap. */ + ring->head = ring->cur = head; + + return (totlen); +} + +static struct net_backend netmap_backend = { + .prefix = "netmap", + .priv_size = sizeof(struct netmap_priv), + .init = netmap_init, + .cleanup = netmap_cleanup, + .send = netmap_send, + .recv = netmap_recv, + .get_cap = netmap_get_cap, + .set_cap = netmap_set_cap, +}; + +/* A clone of the netmap backend, with a different prefix. */ +static struct net_backend vale_backend = { + .prefix = "vale", + .priv_size = sizeof(struct netmap_priv), + .init = netmap_init, + .cleanup = netmap_cleanup, + .send = netmap_send, + .recv = netmap_recv, + .get_cap = netmap_get_cap, + .set_cap = netmap_set_cap, +}; + +DATA_SET(net_backend_set, netmap_backend); +DATA_SET(net_backend_set, vale_backend); + +/* + * Initialize a backend and attach to the frontend. + * This is called during frontend initialization. + * @pbe is a pointer to the backend to be initialized + * @devname is the backend-name as supplied on the command line, + * e.g. -s 2:0,frontend-name,backend-name[,other-args] + * @cb is the receive callback supplied by the frontend, + * and it is invoked in the event loop when a receive + * event is generated in the hypervisor, + * @param is a pointer to the frontend, and normally used as + * the argument for the callback. + */ +int +netbe_init(struct net_backend **ret, const char *devname, net_be_rxeof_t cb, + void *param) +{ + struct net_backend **pbe, *nbe, *tbe = NULL; + int err; + + /* + * Find the network backend that matches the user-provided + * device name. net_backend_set is built using a linker set. + */ + SET_FOREACH(pbe, net_backend_set) { + if (strncmp(devname, (*pbe)->prefix, + strlen((*pbe)->prefix)) == 0) { + tbe = *pbe; + assert(tbe->init != NULL); + assert(tbe->cleanup != NULL); + assert(tbe->send != NULL); + assert(tbe->recv != NULL); + assert(tbe->get_cap != NULL); + assert(tbe->set_cap != NULL); + break; + } + } + + *ret = NULL; + if (tbe == NULL) + return (EINVAL); + nbe = calloc(1, sizeof(*nbe) + tbe->priv_size); + *nbe = *tbe; /* copy the template */ + nbe->fd = -1; + nbe->sc = param; + nbe->be_vnet_hdr_len = 0; + nbe->fe_vnet_hdr_len = 0; + + /* Initialize the backend. */ + err = nbe->init(nbe, devname, cb, param); + if (err) { + free(nbe); + return (err); + } + + *ret = nbe; + + return (0); +} + +void +netbe_cleanup(struct net_backend *be) +{ + + if (be != NULL) { + be->cleanup(be); + free(be); + } +} + +uint64_t +netbe_get_cap(struct net_backend *be) +{ + + assert(be != NULL); + return (be->get_cap(be)); +} + +int +netbe_set_cap(struct net_backend *be, uint64_t features, + unsigned vnet_hdr_len) +{ + int ret; + + assert(be != NULL); + + /* There are only three valid lengths, i.e., 0, 10 and 12. */ + if (vnet_hdr_len && vnet_hdr_len != VNET_HDR_LEN + && vnet_hdr_len != (VNET_HDR_LEN - sizeof(uint16_t))) + return (-1); + + be->fe_vnet_hdr_len = vnet_hdr_len; + + ret = be->set_cap(be, features, vnet_hdr_len); + assert(be->be_vnet_hdr_len == 0 || + be->be_vnet_hdr_len == be->fe_vnet_hdr_len); + + return (ret); +} + +static __inline struct iovec * +iov_trim(struct iovec *iov, int *iovcnt, unsigned int tlen) +{ + struct iovec *riov; + + /* XXX short-cut: assume first segment is >= tlen */ + assert(iov[0].iov_len >= tlen); + + iov[0].iov_len -= tlen; + if (iov[0].iov_len == 0) { + assert(*iovcnt > 1); + *iovcnt -= 1; + riov = &iov[1]; + } else { + iov[0].iov_base = (void *)((uintptr_t)iov[0].iov_base + tlen); + riov = &iov[0]; + } + + return (riov); +} + +ssize_t +netbe_send(struct net_backend *be, struct iovec *iov, int iovcnt) +{ + + assert(be != NULL); + if (be->be_vnet_hdr_len != be->fe_vnet_hdr_len) { + /* + * The frontend uses a virtio-net header, but the backend + * does not. We ignore it (as it must be all zeroes) and + * strip it. + */ + assert(be->be_vnet_hdr_len == 0); + iov = iov_trim(iov, &iovcnt, be->fe_vnet_hdr_len); + } + + return (be->send(be, iov, iovcnt)); +} + +/* + * Try to read a packet from the backend, without blocking. + * If no packets are available, return 0. In case of success, return + * the length of the packet just read. Return -1 in case of errors. + */ +ssize_t +netbe_recv(struct net_backend *be, struct iovec *iov, int iovcnt) +{ + /* Length of prepended virtio-net header. */ + unsigned int hlen = be->fe_vnet_hdr_len; + int ret; + + assert(be != NULL); + + if (hlen && hlen != be->be_vnet_hdr_len) { + /* + * The frontend uses a virtio-net header, but the backend + * does not. We need to prepend a zeroed header. + */ + struct virtio_net_rxhdr *vh; + + assert(be->be_vnet_hdr_len == 0); + + /* + * Get a pointer to the rx header, and use the + * data immediately following it for the packet buffer. + */ + vh = iov[0].iov_base; + iov = iov_trim(iov, &iovcnt, hlen); + + /* + * The only valid field in the rx packet header is the + * number of buffers if merged rx bufs were negotiated. + */ + memset(vh, 0, hlen); + if (hlen == VNET_HDR_LEN) { + vh->vrh_bufs = 1; + } + } + + ret = be->recv(be, iov, iovcnt); + if (ret > 0) { + ret += hlen; + } + + return (ret); +} + +/* + * Read a packet from the backend and discard it. + * Returns the size of the discarded packet or zero if no packet was available. + * A negative error code is returned in case of read error. + */ +ssize_t +netbe_rx_discard(struct net_backend *be) +{ + /* + * MP note: the dummybuf is only used to discard frames, + * so there is no need for it to be per-vtnet or locked. + * We only make it large enough for TSO-sized segment. + */ + static uint8_t dummybuf[65536 + 64]; + struct iovec iov; + + iov.iov_base = dummybuf; + iov.iov_len = sizeof(dummybuf); + + return netbe_recv(be, &iov, 1); +} + |