[libvirt] [PATCHv2 1/2] util: Functions to update host network device's multicast filter
Laine Stump
laine at laine.org
Sun Oct 26 16:12:18 UTC 2014
Note that I've attached a patch that addresses all the issues I raise in
this review. Please try it out; if you approve, I will squash it in and
push the result (with my name added as Signed-Off-By:, so that you don't
have to take all the blame if I screwed something up :-))
Oh, and so that it is officially said: ACK, with my small patch squashed in.
On 10/10/2014 01:55 PM, akrowiak at linux.vnet.ibm.com wrote:
> From: Tony Krowiak <akrowiak at linux.vnet.ibm.com>
>
> This patch provides the utility functions to needed to synchronize the
> changes made to a guest domain network device's multicast filter
> with the corresponding macvtap device's filter on the host:
>
> * Get/add/remove multicast MAC addresses
> * Get the macvtap device's RX filter list
>
> changes from v1:
> * Using virHexToBin function to parse HEX MAC address instead of
> sscanf in virMacAddrParseHex function
> * Using ENOSYS in error messages for empty functions
> * Reading entire file with virFileReadAll function when
> parsing /proc/net/dev_mcast file
> * Using VIR_APPEND_ELEMENT macro when appending array of
> /proc/net/dev_mcast file objects
> * Misc. formatting changes
>
> Signed-off-by: Tony Krowiak <akrowiak at linux.vnet.ibm.com>
> ---
> src/libvirt_private.syms | 4 +
> src/util/virmacaddr.c | 25 ++++
> src/util/virmacaddr.h | 4 +
> src/util/virnetdev.c | 358 ++++++++++++++++++++++++++++++++++++++++++++++
> src/util/virnetdev.h | 10 ++
> 5 files changed, 401 insertions(+), 0 deletions(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index d6265ac..6d06a2c 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -1590,13 +1590,16 @@ virMacAddrIsBroadcastRaw;
> virMacAddrIsMulticast;
> virMacAddrIsUnicast;
> virMacAddrParse;
> +virMacAddrParseHex;
> virMacAddrSet;
> virMacAddrSetRaw;
>
>
> # util/virnetdev.h
> +virNetDevAddMulti;
> virNetDevAddRoute;
> virNetDevClearIPv4Address;
> +virNetDevDelMulti;
> virNetDevExists;
> virNetDevGetIndex;
> virNetDevGetIPv4Address;
> @@ -1604,6 +1607,7 @@ virNetDevGetLinkInfo;
> virNetDevGetMAC;
> virNetDevGetMTU;
> virNetDevGetPhysicalFunction;
> +virNetDevGetRxFilter;
> virNetDevGetVirtualFunctionIndex;
> virNetDevGetVirtualFunctionInfo;
> virNetDevGetVirtualFunctions;
> diff --git a/src/util/virmacaddr.c b/src/util/virmacaddr.c
> index ebd1182..612a409 100644
> --- a/src/util/virmacaddr.c
> +++ b/src/util/virmacaddr.c
> @@ -29,6 +29,7 @@
> #include "c-ctype.h"
> #include "virmacaddr.h"
> #include "virrandom.h"
> +#include "virutil.h"
>
> static const unsigned char virMacAddrBroadcastAddrRaw[VIR_MAC_BUFLEN] =
> { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
> @@ -198,6 +199,30 @@ virMacAddrFormat(const virMacAddr *addr,
> return str;
> }
>
> +/**
> + * virMacAddrParseHex:
> + * @str: string hexadecimal representation of MAC address, e.g., "F801EFCE3aCB"
> + * @addr: 6-byte MAC address
> + *
> + * Parse the hexadecimal representation of a MAC address
> + *
> + * Return 0 upon success, or -1 in case of error.
> + */
> +int
> +virMacAddrParseHex(const char *str, virMacAddrPtr addr)
> +{
> + size_t i;
> +
> + if (strspn(str, "0123456789abcdefABCDEF") != VIR_MAC_HEXLEN ||
> + str[VIR_MAC_HEXLEN])
> + return -1;
> +
> + for (i = 0; i < VIR_MAC_BUFLEN; i++)
> + addr->addr[i] = (virHexToBin(str[2 * i]) << 4 |
> + virHexToBin(str[2 * i + 1]));
> + return 0;
> +}
> +
> void virMacAddrGenerate(const unsigned char prefix[VIR_MAC_PREFIX_BUFLEN],
> virMacAddrPtr addr)
> {
> diff --git a/src/util/virmacaddr.h b/src/util/virmacaddr.h
> index 49efc36..72a285a 100644
> --- a/src/util/virmacaddr.h
> +++ b/src/util/virmacaddr.h
> @@ -27,6 +27,7 @@
> # include "internal.h"
>
> # define VIR_MAC_BUFLEN 6
> +#define VIR_MAC_HEXLEN (VIR_MAC_BUFLEN * 2)
make syntax-check complains about the missing space between # and define
(we mandate proper "nesting" of the spaces after preprocessor #
characters - 1 per level; this helps to remind examiners of the code
just how deeply any piece of code is #ifdefed).
(For future reference - you should always run make syntax-check on each
patch of a series and fix the failures before posting.)
> # define VIR_MAC_PREFIX_BUFLEN 3
> # define VIR_MAC_STRING_BUFLEN (VIR_MAC_BUFLEN * 3)
>
> @@ -50,6 +51,9 @@ void virMacAddrGenerate(const unsigned char prefix[VIR_MAC_PREFIX_BUFLEN],
> virMacAddrPtr addr);
> int virMacAddrParse(const char* str,
> virMacAddrPtr addr) ATTRIBUTE_RETURN_CHECK;
> +int virMacAddrParseHex(const char* str,
> + virMacAddrPtr addr)
> + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
> bool virMacAddrIsUnicast(const virMacAddr *addr);
> bool virMacAddrIsMulticast(const virMacAddr *addr);
> bool virMacAddrIsBroadcastRaw(const unsigned char s[VIR_MAC_BUFLEN]);
> diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
> index db5623a..1410cfe 100644
> --- a/src/util/virnetdev.c
> +++ b/src/util/virnetdev.c
> @@ -56,6 +56,35 @@
>
> VIR_LOG_INIT("util.netdev");
>
> +# define PROC_NET_DEV_MCAST "/proc/net/dev_mcast"
> +# define MAX_MCAST_SIZE 50*14336
> +# define VIR_MCAST_NAME_LEN (IFNAMSIZ + 1)
> +# define VIR_MCAST_INDEX_TOKEN_IDX 0
> +# define VIR_MCAST_NAME_TOKEN_IDX 1
> +# define VIR_MCAST_USERS_TOKEN_IDX 2
> +# define VIR_MCAST_GLOBAL_TOKEN_IDX 3
> +# define VIR_MCAST_ADDR_TOKEN_IDX 4
> +# define VIR_MCAST_NUM_TOKENS 5
> +# define VIR_MCAST_TOKEN_DELIMS " \n"
> +# define VIR_MCAST_ADDR_LEN (VIR_MAC_HEXLEN + 1)
Similar problem - since there is no enclosing #ifdef, these #defines
shouldn't have a space after the #.
> +
> +typedef struct _virNetDevMcastEntry virNetDevMcastEntry;
> +typedef virNetDevMcastEntry *virNetDevMcastEntryPtr;
> +struct _virNetDevMcastEntry {
> + int index;
> + char name[VIR_MCAST_NAME_LEN];
> + int users;
> + bool global;
> + virMacAddr macaddr;
> +};
> +
> +typedef struct _virNetDevMcast virNetDevMcast;
> +typedef virNetDevMcast *virNetDevMcastPtr;
> +struct _virNetDevMcast {
> + size_t nentries;
> + virNetDevMcastEntryPtr *entries;
> +};
I think this would be better named virNetDevMcastList.
> +
> #if defined(HAVE_STRUCT_IFREQ)
> static int virNetDevSetupControlFull(const char *ifname,
> struct ifreq *ifr,
> @@ -1934,6 +1963,266 @@ virNetDevGetLinkInfo(const char *ifname,
> #endif /* defined(__linux__) */
>
>
> +#if defined(SIOCADDMULTI) && defined(HAVE_STRUCT_IFREQ)
> +/**
> + * virNetDevAddMulti:
> + * @ifname: interface name to which to add multicast MAC address
> + * @macaddr: MAC address
> + *
> + * This function adds the @macaddr to the multicast list for a given interface
> + * @ifname.
> + *
> + * Returns 0 in case of success or -1 on failure
> + */
> +int virNetDevAddMulti(const char *ifname,
> + virMacAddrPtr macaddr)
> +{
> + int fd = -1;
> + int ret = -1;
> + struct ifreq ifr;
> +
> + if ((fd = virNetDevSetupControl(ifname, &ifr)) < 0)
> + return -1;
> +
> + ifr.ifr_hwaddr.sa_family = AF_UNSPEC;
> + virMacAddrGetRaw(macaddr, (unsigned char *)ifr.ifr_hwaddr.sa_data);
> +
> + if (ioctl(fd, SIOCADDMULTI, &ifr) < 0) {
> + char macstr[VIR_MAC_STRING_BUFLEN];
> + virReportSystemError(errno,
> + _("Cannot add multicast MAC %s on '%s' interface"),
> + virMacAddrFormat(macaddr, macstr), ifname);
> + goto cleanup;
> + }
> +
> + ret = 0;
> +
> + cleanup:
> + VIR_FORCE_CLOSE(fd);
> + return ret;
> +}
> +#else
> +int virNetDevAddMulti(const char *ifname,
> + virMacAddrPtr macaddr ATTRIBUTE_UNUSED)
> +{
> + char macstr[VIR_MAC_STRING_BUFLEN];
> + virReportSystemError(ENOSYS,
> + _("Cannot add multicast MAC %s on '%s' interface"),
> + virMacAddrFormat(macaddr, macstr), ifname);
To be more useful, this message should instead state
"Unable to add entries to an interface multicast list on this platform"
(which matches the wording of similar ENOSYS error messages)
> + return -1;
> +}
> +#endif
> +
> +#if defined(SIOCDELMULTI) && defined(HAVE_STRUCT_IFREQ)
> +/**
> + * virNetDevDelMulti:
> + * @ifname: interface name from which to delete the multicast MAC address
> + * @macaddr: MAC address
> + *
> + * This function deletes the @macaddr from the multicast list for a given
> + * interface @ifname.
> + *
> + * Returns 0 in case of success or -1 on failure
> + */
> +int virNetDevDelMulti(const char *ifname,
> + virMacAddrPtr macaddr)
> +{
> + int fd = -1;
> + int ret = -1;
> + struct ifreq ifr;
> +
> + if ((fd = virNetDevSetupControl(ifname, &ifr)) < 0)
> + return -1;
> +
> + ifr.ifr_hwaddr.sa_family = AF_UNSPEC;
> + virMacAddrGetRaw(macaddr, (unsigned char *)ifr.ifr_hwaddr.sa_data);
> +
> + if (ioctl(fd, SIOCDELMULTI, &ifr) < 0) {
> + char macstr[VIR_MAC_STRING_BUFLEN];
> + virReportSystemError(errno,
> + _("Cannot add multicast MAC %s on '%s' interface"),
> + virMacAddrFormat(macaddr, macstr), ifname);
> + goto cleanup;
> + }
> +
> + ret = 0;
> +
> + cleanup:
> + VIR_FORCE_CLOSE(fd);
> + return ret;
> +}
> +#else
> +int virNetDevDelMulti(const char *ifname,
> + virMacAddrPtr macaddr ATTRIBUTE_UNUSED)
> +{
> + char macstr[VIR_MAC_STRING_BUFLEN];
> + virReportSystemError(ENOSYS,
> + _("Cannot delete multicast MAC %s on '%s' interface"),
> + virMacAddrFormat(macaddr, macstr), ifname);
Same comment as above.
> + return -1;
> +}
> +#endif
> +
> +static int virNetDevParseMcast(char *buf, virNetDevMcastEntryPtr mcast)
> +{
> + int ifindex;
> + int num;
> + char *next;
> + char *token;
> + char *saveptr;
> + char *endptr;
> +
> + for (ifindex = 0, next = buf; ifindex < VIR_MCAST_NUM_TOKENS; ifindex++,
> + next = NULL) {
> + token = strtok_r(next, VIR_MCAST_TOKEN_DELIMS, &saveptr);
> +
> + if (token == NULL) {
> + virReportSystemError(EINVAL,
> + _("failed to parse multicast address from '%s'"),
> + buf);
> + return -1;
> + }
> +
> + switch (ifindex) {
> + case VIR_MCAST_INDEX_TOKEN_IDX:
> + if (virStrToLong_i(token, &endptr, 10, &num) < 0) {
> + virReportSystemError(EINVAL,
> + _("Failed to parse interface index from '%s'"),
> + buf);
> + return -1;
> +
> + }
> +
> + mcast->index = num;
> +
> + break;
> + case VIR_MCAST_NAME_TOKEN_IDX:
> + if (virStrncpy(mcast->name, token, strlen(token),
> + VIR_MCAST_NAME_LEN) == NULL) {
> + virReportSystemError(EINVAL,
> + _("Failed to parse network device name from '%s'"),
> + buf);
> + return -1;
> + }
> +
> + break;
> + case VIR_MCAST_USERS_TOKEN_IDX:
> + if (virStrToLong_i(token, &endptr, 10, &num) < 0) {
> + virReportSystemError(EINVAL,
> + _("Failed to parse users from '%s'"),
> + buf);
> + return -1;
> +
> + }
> +
> + mcast->users = num;
> +
> + break;
> + case VIR_MCAST_GLOBAL_TOKEN_IDX:
> + if (virStrToLong_i(token, &endptr, 10, &num) < 0) {
> + virReportSystemError(EINVAL,
> + _("Failed to parse users from '%s'"),
> + buf);
> + return -1;
> +
> + }
> +
> + mcast->global = num;
> +
> + break;
> + case VIR_MCAST_ADDR_TOKEN_IDX:
> + if (virMacAddrParseHex((const char*)token,
> + &mcast->macaddr) < 0) {
> + virReportSystemError(EINVAL,
> + _("Failed to parse MAC address from '%s'"),
> + buf);
> + }
> +
> + break;
> + default:
> + break;
> + }
> + }
> +
> + return 0;
> +}
> +
> +
> +static void virNetDevMcastEntryListFree(size_t nentries,
> + virNetDevMcastEntryPtr *entries)
Since you already have virNetDevMcast (or, following my suggestion
"virNetDevMcastList") defined to be a struct that has an entries and an
nentries, why not send a pointer to one of those rather than the
separate args? If you did this, the name of the function should be
changed to virNetDevMcastListClear(), since it's not freeing the object
itself, but clearing out its contents.
> +{
> + size_t i;
> +
> + if (entries) {
The "if (entries)" is superfluous, since you wouldn't get into the loop
if nentries == 0, and VIR_FREE() is safe to call with a NULL arg.
> + for (i = 0; i < nentries; i++)
> + VIR_FREE(entries[i]);
> +
> + VIR_FREE(entries);
> + }
> +}
> +
> +
> +static int virNetDevGetMcast(const char *ifname,
> + virNetDevMcastPtr mcast)
> +{
> + char *cur = NULL;
> + char *buf = NULL;
> + char *next = NULL;
> + int ret = -1, len;
> + virNetDevMcastEntryPtr entry = NULL;
> + virNetDevMcastEntryPtr *entries = NULL;
> + size_t nentries = 0;
The code would be simpler if it just populated mcast directly, rather
than putting the list into a temporary location first. This would also
allow changing virNetDevMcastListClear
> + mcast->entries = NULL;
> + mcast->nentries = 0;
> +
> + /* Read entire multicast table into memory */
> + if ((len = virFileReadAll(PROC_NET_DEV_MCAST, MAX_MCAST_SIZE, &buf)) <= 0)
> + goto cleanup;
> +
> + cur = buf;
> +
> + while (cur) {
> + if (!entry) {
> + if (VIR_ALLOC(entry))
> + goto cleanup;
> + }
> +
> + next = strchr(cur, '\n');
> +
> + if (next) {
> + next++;
> + }
> +
> + if (virNetDevParseMcast(cur, entry))
> + goto cleanup;
> +
> + /* Only return global multicast MAC addresses for
> + * specified interface */
> + if (entry->global && STREQ(ifname, entry->name)) {
> + if (VIR_APPEND_ELEMENT(entries, nentries, entry))
> + goto cleanup;
> +
> + entry = NULL;
> + } else {
> + memset(entry, 0, sizeof(virNetDevMcastEntry));
> + }
> +
> + cur = next && ((next - buf) < len) ? next : NULL;
> + }
> +
> + mcast->nentries = nentries;
> + mcast->entries = entries;
> + ret = 0;
> + cleanup:
> + if (ret < 0)
> + virNetDevMcastEntryListFree(nentries, entries);
> +
> + VIR_FREE(entry);
> +
> + return ret;
> +}
> +
> +
> VIR_ENUM_IMPL(virNetDevRxFilterMode,
> VIR_NETDEV_RX_FILTER_MODE_LAST,
> "none",
> @@ -1941,6 +2230,38 @@ VIR_ENUM_IMPL(virNetDevRxFilterMode,
> "all");
>
>
> +static int virNetDevGetMulticastTable(const char *ifname,
> + virNetDevRxFilterPtr filter)
> +{
> + size_t i;
> + int ret = -1;
> + virNetDevMcast mcast;
> + filter->multicast.nTable = 0;
> + filter->multicast.table = NULL;
> +
> + if (virNetDevGetMcast(ifname, &mcast) < 0)
> + goto cleanup;
> +
> + if (mcast.nentries > 0) {
> + if (VIR_ALLOC_N(filter->multicast.table, mcast.nentries))
> + goto cleanup;
> +
> + for (i = 0; i < mcast.nentries; i++) {
> + virMacAddrSet(&filter->multicast.table[i],
> + &mcast.entries[i]->macaddr);
> + }
> +
> + filter->multicast.nTable = mcast.nentries;
> + }
> +
> + ret = 0;
> + cleanup:
> + virNetDevMcastEntryListFree(mcast.nentries, mcast.entries);
> +
> + return ret;
> +}
> +
> +
> virNetDevRxFilterPtr
> virNetDevRxFilterNew(void)
> {
> @@ -1963,3 +2284,40 @@ virNetDevRxFilterFree(virNetDevRxFilterPtr filter)
> VIR_FREE(filter);
> }
> }
> +
> +
> +/**
> + * virNetDevGetRxFilter:
> + * This function supplies the RX filter list for a given device interface
> + *
> + * @ifname: Name of the interface
> + * @filter: The RX filter list
> + *
> + * Returns 0 or -1 on failure.
> + */
> +int virNetDevGetRxFilter(const char *ifname,
> + virNetDevRxFilterPtr *filter)
> +{
> + int ret = -1;
> + virNetDevRxFilterPtr fil = virNetDevRxFilterNew();
> +
> + if (!fil)
> + goto cleanup;
> +
> + if (virNetDevGetMAC(ifname, &fil->mac))
> + goto cleanup;
> +
> + if (virNetDevGetMulticastTable(ifname, fil))
> + goto cleanup;
> +
> + ret = 0;
> + cleanup:
> + if (ret < 0) {
> + virNetDevRxFilterFree(fil);
> + fil = NULL;
> + }
> +
> + *filter = fil;
> +
> + return ret;
> +}
> diff --git a/src/util/virnetdev.h b/src/util/virnetdev.h
> index 2a6e67d..ac4beff 100644
> --- a/src/util/virnetdev.h
> +++ b/src/util/virnetdev.h
> @@ -189,5 +189,15 @@ int virNetDevGetLinkInfo(const char *ifname,
> virNetDevRxFilterPtr virNetDevRxFilterNew(void)
> ATTRIBUTE_RETURN_CHECK;
> void virNetDevRxFilterFree(virNetDevRxFilterPtr filter);
> +int virNetDevGetRxFilter(const char *ifname,
> + virNetDevRxFilterPtr *filter)
> + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
> +
> +int virNetDevAddMulti(const char *ifname,
> + virMacAddrPtr macaddr)
> + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
> +int virNetDevDelMulti(const char *ifname,
> + virMacAddrPtr macaddr)
> + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
>
> #endif /* __VIR_NETDEV_H__ */
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