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Extending IpPrefix class to return the subnet associated to any given prefix #184

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Merged
lguohan merged 2 commits into from
Feb 8, 2018
Merged

Extending IpPrefix class to return the subnet associated to any given prefix #184

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61b9d7b
Extending IpPrefix class to return the subnet associated to any given…
Jan 25, 2018
b7d12ac
Adding UTs for previous IpPrefix class extension.
Feb 8, 2018
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46 changes: 45 additions & 1 deletion common/ipprefix.h
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@

#include <assert.h>
#include <stdexcept>
#include <arpa/inet.h>
#include "ipaddress.h"

namespace swss {
Expand Down Expand Up @@ -65,7 +66,7 @@ class IpPrefix
{
ip_addr_t ipa;
ipa.family = AF_INET6;

assert(m_mask >= 0 && m_mask <= 128);
int mid = m_mask >> 3;
int bits = m_mask & 0x7;
Expand Down Expand Up @@ -133,6 +134,49 @@ class IpPrefix
}
}

inline IpPrefix getSubnet() const
{
switch (m_ip.getIp().family)
{
case AF_INET:
{
uint32_t ipaddr = m_ip.getV4Addr();
uint32_t mask = getMask().getV4Addr();

ipaddr &= mask;
return IpPrefix(ipaddr, m_mask);
}

case AF_INET6:
{
const uint8_t *ipaddr = m_ip.getV6Addr();
uint8_t subnet[INET6_ADDRSTRLEN] = {0};
memcpy(subnet, ipaddr, 16);

IpAddress ip6mask = getMask();
const uint8_t *mask = ip6mask.getV6Addr();

for (int i = 0; i < 16; ++i)
{
subnet[i] &= mask[i];
}

char buf[INET6_ADDRSTRLEN];
std::string ipStr(inet_ntop(AF_INET6,
&subnet,
buf,
INET6_ADDRSTRLEN));

return IpPrefix(ipStr + "/" + std::to_string(m_mask));
}

default:
{
throw std::logic_error("Invalid family");
}
}
}

inline bool operator<(const IpPrefix &o) const
{
if (m_mask != o.m_mask)
Expand Down
29 changes: 29 additions & 0 deletions tests/ipprefix_ut.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -115,3 +115,32 @@ TEST(IpPrefix, subnet)
EXPECT_FALSE(prefix1.isAddressInSubnet(ip3));
EXPECT_FALSE(prefix2.isAddressInSubnet(ip3));
}

TEST(IpPrefix, getSubnet)
{
// IPv4 prefixes
IpPrefix prefix1("1.1.1.0/0");
IpPrefix prefix2("1.1.1.191/24");
IpPrefix prefix3("1.1.1.191/26");
IpPrefix prefix4("1.1.191.1/20");
IpPrefix prefix5("2.2.2.2/32");

// IPv6 prefixes
IpPrefix prefix6("::/0");
IpPrefix prefix7("2001:4898:f0:f153:357c:77b2:49c9:627c/64");
IpPrefix prefix8("2001:4898:f0:f153:357c:77b2:49c9:627c/63");
IpPrefix prefix9("2001:4898:f0:f153:357c:77b2:49c9:627c/45");
IpPrefix prefix10("2001:4898:f0:f153:357c:77b2:49c9:627c/128");

EXPECT_EQ("0.0.0.0/0", prefix1.getSubnet().to_string());
EXPECT_EQ("1.1.1.0/24", prefix2.getSubnet().to_string());
EXPECT_EQ("1.1.1.128/26", prefix3.getSubnet().to_string());
EXPECT_EQ("1.1.176.0/20", prefix4.getSubnet().to_string());
EXPECT_EQ("2.2.2.2/32", prefix5.getSubnet().to_string());

EXPECT_EQ("::/0", prefix6.getSubnet().to_string());
EXPECT_EQ("2001:4898:f0:f153::/64", prefix7.getSubnet().to_string());
EXPECT_EQ("2001:4898:f0:f152::/63", prefix8.getSubnet().to_string());
EXPECT_EQ("2001:4898:f0::/45", prefix9.getSubnet().to_string());
EXPECT_EQ("2001:4898:f0:f153:357c:77b2:49c9:627c/128", prefix10.getSubnet().to_string());
}