On Mon, 18 Dec 2017 17:46:23 +0100
Adrien Mazarguil <adrien.mazarg...@6wind.com> wrote:
>
> /**
> + * Destroy a hyperv context instance.
> + *
> + * @param ctx
> + * Context to destroy.
> + */
> +static void
> +hyperv_ctx_destroy(struct hyperv_ctx *ctx)
> +{
> + if (ctx->pipe[0] != -1)
> + close(ctx->pipe[0]);
> + if (ctx->pipe[1] != -1)
> + close(ctx->pipe[1]);
> + /* Poisoning for debugging purposes. */
> + memset(ctx, 0x22, sizeof(*ctx));
Don't leave debug code in submitted drivers
> + free(ctx);
> +}
> +
> +/**
> + * Iterate over system network interfaces.
> + *
> + * This function runs a given callback function for each netdevice found on
> + * the system.
> + *
> + * @param func
> + * Callback function pointer. List traversal is aborted when this function
> + * returns a nonzero value.
> + * @param ...
> + * Variable parameter list passed as @p va_list to @p func.
> + *
> + * @return
> + * 0 when the entire list is traversed successfully, a negative error code
> + * in case or failure, or the nonzero value returned by @p func when list
> + * traversal is aborted.
> + */
> +static int
> +hyperv_foreach_iface(int (*func)(const struct if_nameindex *iface,
> + const struct ether_addr *eth_addr,
> + va_list ap), ...)
> +{
> + struct if_nameindex *iface = if_nameindex();
> + int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
> + unsigned int i;
> + int ret = 0;
> +
> + if (!iface) {
> + ret = -ENOBUFS;
> + ERROR("cannot retrieve system network interfaces");
> + goto error;
> + }
> + if (s == -1) {
> + ret = -errno;
> + ERROR("cannot open socket: %s", rte_strerror(errno));
> + goto error;
> + }
> + for (i = 0; iface[i].if_name; ++i) {
> + struct ifreq req;
> + struct ether_addr eth_addr;
> + va_list ap;
> +
> + strncpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name));
> + if (ioctl(s, SIOCGIFHWADDR, &req) == -1) {
> + WARN("cannot retrieve information about interface"
> + " \"%s\": %s",
> + req.ifr_name, rte_strerror(errno));
> + continue;
> + }
> + memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data,
> + RTE_DIM(eth_addr.addr_bytes));
> + va_start(ap, func);
> + ret = func(&iface[i], ð_addr, ap);
> + va_end(ap);
> + if (ret)
> + break;
> + }
> +error:
> + if (s != -1)
> + close(s);
> + if (iface)
> + if_freenameindex(iface);
> + return ret;
> +}
> +
> +/**
> + * Determine if a network interface is NetVSC.
> + *
> + * @param[in] iface
> + * Pointer to netdevice description structure (name and index).
> + *
> + * @return
> + * A nonzero value when interface is detected as NetVSC. In case of error,
> + * rte_errno is updated and 0 returned.
> + */
> +static int
> +hyperv_iface_is_netvsc(const struct if_nameindex *iface)
> +{
> + static const char temp[] = "/sys/class/net/%s/device/class_id";
> + char path[snprintf(NULL, 0, temp, iface->if_name) + 1];
Doing this snprintf is gross. Either use PATH_MAX or asprintf
> + FILE *f;
> + int ret;
> + int len = 0;
> +
> + snprintf(path, sizeof(path), temp, iface->if_name);
> + f = fopen(path, "r");
> + if (!f) {
> + rte_errno = errno;
> + return 0;
> + }
> + ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
> + if (ret == EOF)
> + rte_errno = errno;
> + ret = len == (int)strlen(NETVSC_CLASS_ID);
> + fclose(f);
> + return ret;
> +}
> +
> +/**
> + * Retrieve the last component of a path.
> + *
> + * This is a simplified basename() that does not modify its input buffer to
> + * handle trailing backslashes.
> + *
> + * @param[in] path
> + * Path to retrieve the last component from.
> + *
> + * @return
> + * Pointer to the last component.
> + */
> +static const char *
> +hyperv_basename(const char *path)
> +{
> + const char *tmp = path;
> +
> + while (*tmp)
> + if (*(tmp++) == '/')
Too may ()
> + path = tmp;
> + return path;
> +}
> +
> +/**
> + * Retrieve network interface data from sysfs symbolic link.
> + *
> + * @param[out] buf
> + * Output data buffer.
> + * @param size
> + * Output buffer size.
> + * @param[in] if_name
> + * Netdevice name.
> + * @param[in] relpath
> + * Symbolic link path relative to netdevice sysfs entry.
> + *
> + * @return
> + * 0 on success, a negative error code otherwise.
> + */
> +static int
> +hyperv_sysfs_readlink(char *buf, size_t size, const char *if_name,
> + const char *relpath)
> +{
> + int ret;
> +
> + ret = snprintf(buf, size, "/sys/class/net/%s/%s", if_name, relpath);
> + if (ret == -1 || (size_t)ret >= size - 1)
> + return -ENOBUFS;
> + ret = readlink(buf, buf, size);
> + if (ret == -1)
> + return -errno;
> + if ((size_t)ret >= size - 1)
> + return -ENOBUFS;
> + buf[ret] = '\0';
> + return 0;
> +}
> +
> +/**
> + * Probe a network interface to associate with hyperv context.
> + *
> + * This function determines if the network device matches the properties of
> + * the NetVSC interface associated with the hyperv context and communicates
> + * its bus address to the fail-safe PMD instance if so.
> + *
> + * It is normally used with hyperv_foreach_iface().
> + *
> + * @param[in] iface
> + * Pointer to netdevice description structure (name and index).
> + * @param[in] eth_addr
> + * MAC address associated with @p iface.
> + * @param ap
> + * Variable arguments list comprising:
> + *
> + * - struct hyperv_ctx *ctx:
> + * Context to associate network interface with.
> + *
> + * @return
> + * A nonzero value when interface matches, 0 otherwise or in case of
> + * error.
> + */
> +static int
> +hyperv_device_probe(const struct if_nameindex *iface,
> + const struct ether_addr *eth_addr,
> + va_list ap)
> +{
> + struct hyperv_ctx *ctx = va_arg(ap, struct hyperv_ctx *);
> + char buf[RTE_MAX(sizeof(ctx->yield), 256u)];
> + const char *addr;
> + size_t len;
> + int ret;
> +
> + /* Skip non-matching or unwanted NetVSC interfaces. */
> + if (ctx->if_index == iface->if_index) {
> + if (!strcmp(ctx->if_name, iface->if_name))
> + return 0;
> + DEBUG("NetVSC interface \"%s\" (index %u) renamed \"%s\"",
> + ctx->if_name, ctx->if_index, iface->if_name);
> + strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
> + return 0;
> + }
> + if (hyperv_iface_is_netvsc(iface))
> + return 0;
> + if (!is_same_ether_addr(eth_addr, &ctx->if_addr))
> + return 0;
> + /* Look for associated PCI device. */
> + ret = hyperv_sysfs_readlink(buf, sizeof(buf), iface->if_name,
> + "device/subsystem");
> + if (ret)
> + return 0;
> + if (strcmp(hyperv_basename(buf), "pci"))
> + return 0;
> + ret = hyperv_sysfs_readlink(buf, sizeof(buf), iface->if_name,
> + "device");
> + if (ret)
> + return 0;
> + addr = hyperv_basename(buf);
> + len = strlen(addr);
> + if (!len)
> + return 0;
> + /* Send PCI device argument to fail-safe PMD instance if updated. */
> + if (!strcmp(addr, ctx->yield))
> + return 1;
> + DEBUG("associating PCI device \"%s\" with NetVSC interface \"%s\""
> + " (index %u)",
> + addr, ctx->if_name, ctx->if_index);
> + memmove(buf, addr, len + 1);
> + addr = buf;
> + buf[len] = '\n';
> + ret = write(ctx->pipe[1], addr, len + 1);
> + buf[len] = '\0';
> + if (ret == -1) {
> + if (errno == EINTR || errno == EAGAIN)
> + return 1;
> + WARN("cannot associate PCI device name \"%s\" with interface"
> + " \"%s\": %s",
> + addr, ctx->if_name, rte_strerror(errno));
> + return 1;
> + }
> + if ((size_t)ret != len + 1) {
> + /*
> + * Attempt to override previous partial write, no need to
> + * recover if that fails.
> + */
> + ret = write(ctx->pipe[1], "\n", 1);
> + (void)ret;
> + return 1;
> + }
> + fsync(ctx->pipe[1]);
> + memcpy(ctx->yield, addr, len + 1);
> + return 1;
> +}
> +
> +/**
> + * Alarm callback that regularly probes system network interfaces.
> + *
> + * This callback runs at a frequency determined by HYPERV_PROBE_MS as long
> + * as an hyperv context instance exists.
> + *
> + * @param arg
> + * Ignored.
> + */
> +static void
> +hyperv_alarm(void *arg)
> +{
> + struct hyperv_ctx *ctx;
> + int ret;
> +
> + (void)arg;
I assume you are trying to suppress unused warnings.
The DPDK method of doing this __rte_unused
> + LIST_FOREACH(ctx, &hyperv_ctx_list, entry) {
> + ret = hyperv_foreach_iface(hyperv_device_probe, ctx);
> + if (ret)
> + break;
> + }
> + if (!hyperv_ctx_count)
> + return;
> + ret = rte_eal_alarm_set(HYPERV_PROBE_MS * 1000, hyperv_alarm, NULL);
> + if (ret < 0) {
> + ERROR("unable to reschedule alarm callback: %s",
> + rte_strerror(-ret));
> + }
> +}
> +
> +/**
> + * Probe a NetVSC interface to generate a hyperv context from.
> + *
> + * This function instantiates hyperv contexts either for all NetVSC devices
> + * found on the system or only a subset provided as device arguments.
> + *
> + * It is normally used with hyperv_foreach_iface().
> + *
> + * @param[in] iface
> + * Pointer to netdevice description structure (name and index).
> + * @param[in] eth_addr
> + * MAC address associated with @p iface.
> + * @param ap
> + * Variable arguments list comprising:
> + *
> + * - const char *name:
> + * Name associated with current driver instance.
> + *
> + * - struct rte_kvargs *kvargs:
> + * Device arguments provided to current driver instance.
> + *
> + * - unsigned int specified:
> + * Number of specific netdevices provided as device arguments.
> + *
> + * - unsigned int *matched:
> + * The number of specified netdevices matched by this function.
> + *
> + * @return
> + * A nonzero value when interface matches, 0 otherwise or in case of
> + * error.
> + */
> +static int
> +hyperv_netvsc_probe(const struct if_nameindex *iface,
> + const struct ether_addr *eth_addr,
> + va_list ap)
> +{
> + const char *name = va_arg(ap, const char *);
> + struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *);
> + unsigned int specified = va_arg(ap, unsigned int);
> + unsigned int *matched = va_arg(ap, unsigned int *);
> + unsigned int i;
> + struct hyperv_ctx *ctx;
> + uint16_t port_id;
> + int ret;
> +
> + /* Probe all interfaces when none are specified. */
> + if (specified) {
> + for (i = 0; i != kvargs->count; ++i) {
> + const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
> +
> + if (!strcmp(pair->key, HYPERV_ARG_IFACE)) {
> + if (!strcmp(pair->value, iface->if_name))
> + break;
> + } else if (!strcmp(pair->key, HYPERV_ARG_MAC)) {
> + struct ether_addr tmp;
> +
> + if (ether_addr_from_str(&tmp, pair->value)) {
> + ERROR("invalid MAC address format"
> + " \"%s\"",
> + pair->value);
> + return -EINVAL;
> + }
> + if (!is_same_ether_addr(eth_addr, &tmp))
> + break;
> + }
> + }
> + if (i == kvargs->count)
> + return 0;
> + ++(*matched);
> + }
> + /* Weed out interfaces already handled. */
> + LIST_FOREACH(ctx, &hyperv_ctx_list, entry)
> + if (ctx->if_index == iface->if_index)
> + break;
> + if (ctx) {
> + if (!specified)
> + return 0;
> + WARN("interface \"%s\" (index %u) is already handled, skipping",
> + iface->if_name, iface->if_index);
> + return 0;
> + }
> + if (!hyperv_iface_is_netvsc(iface)) {
> + if (!specified)
> + return 0;
> + WARN("interface \"%s\" (index %u) is not NetVSC, skipping",
> + iface->if_name, iface->if_index);
> + return 0;
> + }
> + /* Create interface context. */
> + ctx = calloc(1, sizeof(*ctx));
> + if (!ctx) {
> + ret = -errno;
> + ERROR("cannot allocate context for interface \"%s\": %s",
> + iface->if_name, rte_strerror(errno));
> + goto error;
> + }
> + ctx->id = hyperv_ctx_count;
> + strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
> + ctx->if_index = iface->if_index;
> + ctx->if_addr = *eth_addr;
> + ctx->pipe[0] = -1;
> + ctx->pipe[1] = -1;
> + ctx->yield[0] = '\0';
> + if (pipe(ctx->pipe) == -1) {
> + ret = -errno;
> + ERROR("cannot allocate control pipe for interface \"%s\": %s",
> + ctx->if_name, rte_strerror(errno));
> + goto error;
> + }
> + for (i = 0; i != RTE_DIM(ctx->pipe); ++i) {
> + int flf = fcntl(ctx->pipe[i], F_GETFL);
> + int fdf = fcntl(ctx->pipe[i], F_GETFD);
> +
> + if (flf != -1 &&
> + fcntl(ctx->pipe[i], F_SETFL, flf | O_NONBLOCK) != -1 &&
> + fdf != -1 &&
> + fcntl(ctx->pipe[i], F_SETFD,
> + i ? fdf | FD_CLOEXEC : fdf & ~FD_CLOEXEC) != -1)
> + continue;
> + ret = -errno;
> + ERROR("cannot toggle non-blocking or close-on-exec flags on"
> + " control file descriptor #%u (%d): %s",
> + i, ctx->pipe[i], rte_strerror(errno));
> + goto error;
> + }
> + /* Generate virtual device name and arguments. */
> + i = 0;
> + ret = snprintf(ctx->name, sizeof(ctx->name), "%s_id%u",
> + name, ctx->id);
> + if (ret == -1 || (size_t)ret >= sizeof(ctx->name) - 1)
> + ++i;
> + ret = snprintf(ctx->devname, sizeof(ctx->devname), "net_failsafe_%s",
> + ctx->name);
> + if (ret == -1 || (size_t)ret >= sizeof(ctx->devname) - 1)
> + ++i;
> + /*
> + * Note: bash replaces the default sh interpreter used by popen()
> + * because as seen with dash, POSIX-compliant shells do not
> + * necessarily support redirections with file descriptor numbers
> + * above 9.
> + */
> + ret = snprintf(ctx->devargs, sizeof(ctx->devargs),
> + "exec(exec bash -c "
> + "'while read -r tmp <&%u 2> /dev/null;"
> + " do dev=$tmp; done;"
> + " echo $dev"
> + "'),dev(net_tap_%s,remote=%s)",
> + ctx->pipe[0], ctx->name, ctx->if_name);
Write real code. Shelling out to bash is messy, error prone and potential
security issue.
> + if (ret == -1 || (size_t)ret >= sizeof(ctx->devargs) - 1)
> + ++i;
> + if (i) {
> + ret = -ENOBUFS;
> + ERROR("generated virtual device name or argument list too long"
> + " for interface \"%s\"", ctx->if_name);
> + goto error;
> + }
> + /*
> + * Remove any competing rte_eth_dev entries sharing the same MAC
> + * address, fail-safe instances created by this PMD will handle them
> + * as sub-devices later.
> + */
> + RTE_ETH_FOREACH_DEV(port_id) {
> + struct rte_device *dev = rte_eth_devices[port_id].device;
> + struct rte_bus *bus = rte_bus_find_by_device(dev);
> + struct ether_addr tmp;
> +
> + rte_eth_macaddr_get(port_id, &tmp);
> + if (!is_same_ether_addr(eth_addr, &tmp))
> + continue;
> + WARN("removing device \"%s\" with identical MAC address to"
> + " re-create it as a fail-safe sub-device",
> + dev->name);
> + if (!bus)
> + ret = -EINVAL;
> + else
> + ret = rte_eal_hotplug_remove(bus->name, dev->name);
> + if (ret < 0) {
> + ERROR("unable to remove device \"%s\": %s",
> + dev->name, rte_strerror(-ret));
> + goto error;
> + }
> + }
> + /* Request virtual device generation. */
> + DEBUG("generating virtual device \"%s\" with arguments \"%s\"",
> + ctx->devname, ctx->devargs);
> + ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
> + if (ret)
> + goto error;
> + LIST_INSERT_HEAD(&hyperv_ctx_list, ctx, entry);
> + ++hyperv_ctx_count;
> + DEBUG("added NetVSC interface \"%s\" to context list", ctx->if_name);
> + return 0;
> +error:
> + if (ctx)
> + hyperv_ctx_destroy(ctx);
> + return ret;
> +}
> +
> +/**
> * Probe NetVSC interfaces.
> *
> + * This function probes system netdevices according to the specified device
> + * arguments and starts a periodic alarm callback to notify the resulting
> + * fail-safe PMD instances of their sub-devices whereabouts.
> + *
> * @param dev
> * Virtual device context for PMD instance.
> *
> @@ -92,12 +706,38 @@ hyperv_vdev_probe(struct rte_vdev_device *dev)
> const char *args = rte_vdev_device_args(dev);
> struct rte_kvargs *kvargs = rte_kvargs_parse(args ? args : "",
> hyperv_arg);
> + unsigned int specified = 0;
> + unsigned int matched = 0;
> + unsigned int i;
> + int ret;
>
> DEBUG("invoked as \"%s\", using arguments \"%s\"", name, args);
> if (!kvargs) {
> ERROR("cannot parse arguments list");
> goto error;
> }
> + for (i = 0; i != kvargs->count; ++i) {
> + const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
> +
> + if (!strcmp(pair->key, HYPERV_ARG_IFACE) ||
> + !strcmp(pair->key, HYPERV_ARG_MAC))
> + ++specified;
> + }
> + rte_eal_alarm_cancel(hyperv_alarm, NULL);
> + /* Gather interfaces. */
> + ret = hyperv_foreach_iface(hyperv_netvsc_probe, name, kvargs,
> + specified, &matched);
> + if (ret < 0)
> + goto error;
> + if (matched < specified)
> + WARN("some of the specified parameters did not match valid"
> + " network interfaces");
> + ret = rte_eal_alarm_set(HYPERV_PROBE_MS * 1000, hyperv_alarm, NULL);
> + if (ret < 0) {
> + ERROR("unable to schedule alarm callback: %s",
> + rte_strerror(-ret));
> + goto error;
> + }
> error:
> if (kvargs)
> rte_kvargs_free(kvargs);
> @@ -108,6 +748,9 @@ hyperv_vdev_probe(struct rte_vdev_device *dev)
> /**
> * Remove PMD instance.
> *
> + * The alarm callback and underlying hyperv context instances are only
> + * destroyed after the last PMD instance is removed.
> + *
> * @param dev
> * Virtual device context for PMD instance.
> *
> @@ -118,7 +761,16 @@ static int
> hyperv_vdev_remove(struct rte_vdev_device *dev)
> {
> (void)dev;
> - --hyperv_ctx_inst;
> + if (--hyperv_ctx_inst)
> + return 0;
> + rte_eal_alarm_cancel(hyperv_alarm, NULL);
> + while (!LIST_EMPTY(&hyperv_ctx_list)) {
> + struct hyperv_ctx *ctx = LIST_FIRST(&hyperv_ctx_list);
> +
> + LIST_REMOVE(ctx, entry);
> + --hyperv_ctx_count;
> + hyperv_ctx_destroy(ctx);
> + }
> return 0;
> }
>
