Re: [libvirt] [PATCH 1/3] Utility functions to produce an IPv4 broadcast address

On 12/31/2010 06:33 AM, Laine Stump wrote: > These functions work only for IPv4, becasue IPv6 doesn't have the same > concept of "broadcast address" as IPv4. They merely OR the inverse of > the netmask with the given host address, thus turning on all the host > bits. > --- > src/libvirt_private.syms | 2 + > src/util/network.c | 55 > ++++++++++++++++++++++++++++++++++++++++++++++ > src/util/network.h | 6 +++++ > 3 files changed, 63 insertions(+), 0 deletions(-) > > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms > index a959ad9..19e581c 100644 > --- a/src/libvirt_private.syms > +++ b/src/libvirt_private.syms > @@ -558,6 +558,8 @@ virShrinkN; > > > # network.h > +virSocketAddrBroadcast; > +virSocketAddrBroadcastByPrefix; > virSocketAddrIsNetmask; > virSocketAddrMask; > virSocketAddrMaskByPrefix; > diff --git a/src/util/network.c b/src/util/network.c > index 61044fc..f58986e 100644 > --- a/src/util/network.c > +++ b/src/util/network.c > @@ -341,6 +341,61 @@ virSocketAddrMaskByPrefix(virSocketAddrPtr addr, > unsigned int prefix) > } > > /** > + * virSocketAddrBroadcast: > + * @addr: address that needs to be turned into broadcast address > (IPv4 only) > + * @netmask: the netmask address > + * @broadcast: virSocketAddr to recieve the broadcast address > + * > + * Mask ON the host bits of @addr according to @netmask, turning it > + * into a broadcast address. > + * > + * Returns 0 in case of success, or -1 on error. > + */ > +int > +virSocketAddrBroadcast(const virSocketAddrPtr addr, > + const virSocketAddrPtr netmask, > + virSocketAddrPtr broadcast) > +{ > + if ((addr->data.stor.ss_family != AF_INET) || > + (netmask->data.stor.ss_family != AF_INET)) { > + broadcast->data.stor.ss_family = AF_UNSPEC; > + return -1; > + } > + > + broadcast->data.stor.ss_family = AF_INET; > + broadcast->len = addr->len; > + broadcast->data.inet4.sin_addr.s_addr > + = (addr->data.inet4.sin_addr.s_addr > + | ~netmask->data.inet4.sin_addr.s_addr); > + return 0; > +} > + > +/** > + * virSocketAddrBroadcastByPrefix: > + * @addr: address that needs to be turned into broadcast address > (IPv4 only) > + * @prefix: prefix (# of 1 bits) of netmask to apply > + * @broadcast: virSocketAddr to recieve the broadcast address > + * > + * Mask off the host bits of @addr according to @prefix, turning it > + * into a network address. > + * > + * Returns 0 in case of success, or -1 on error. > + */ > +int > +virSocketAddrBroadcastByPrefix(const virSocketAddrPtr addr, > + unsigned int prefix, > + virSocketAddrPtr broadcast) > +{ > + virSocketAddr netmask; > + > + if (virSocketAddrPrefixToNetmask(prefix,&netmask, > + addr->data.stor.ss_family)< 0) > + return -1; > + > + return virSocketAddrBroadcast(addr,&netmask, broadcast); > +} > + > +/** > * virSocketCheckNetmask: > * @addr1: a first network address > * @addr2: a second network address > diff --git a/src/util/network.h b/src/util/network.h > index 2fcee43..bcbc607 100644 > --- a/src/util/network.h > +++ b/src/util/network.h > @@ -77,6 +77,12 @@ int virSocketAddrMask (virSocketAddrPtr addr, > const virSocketAddrPtr netmask); > int virSocketAddrMaskByPrefix(virSocketAddrPtr addr, > unsigned int prefix); > +int virSocketAddrBroadcast(const virSocketAddrPtr addr, > + const virSocketAddrPtr netmask, > + virSocketAddrPtr broadcast); > +int virSocketAddrBroadcastByPrefix(const virSocketAddrPtr addr, > + unsigned int prefix, > + virSocketAddrPtr broadcast); > > int virSocketGetNumNetmaskBits(const virSocketAddrPtr netmask); > int virSocketAddrPrefixToNetmask(unsigned int prefix, ACK.