[go] net/netip: fix invalid representation of Prefix
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:09:06 PM8/20/22
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Joseph Tsai has uploaded this change for review.
net/netip: fix invalid representation of Prefix
For a given Addr, make it such that there is exactly one invalid representation.
This allows invalid representations to also be comparable.
To ensure that the zero value of Prefix is invalid, we modify the encoding
of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
This simplifies IsValid to simply checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 71 insertions(+), 55 deletions(-)
diff --git a/src/net/netip/netip.go b/src/net/netip/netip.go
index b5d55ac..9738334 100644
--- a/src/net/netip/netip.go
+++ b/src/net/netip/netip.go
@@ -1235,20 +1235,11 @@
type Prefix struct {
ip Addr
- // bits is logically a uint8 (storing [0,128]) but also
- // encodes an "invalid" bit, currently represented by the
- // invalidPrefixBits sentinel value. It could be packed into
- // the uint8 more with more complicated expressions in the
- // accessors, but the extra byte (in padding anyway) doesn't
- // hurt and simplifies code below.
- bits int16
+ // bitsPlusOne stores the prefix bit length plus one.
+ // A Prefix is valid if and only if bitsPlusOne is non-zero.
+ bitsPlusOne uint8
}
-// invalidPrefixBits is the Prefix.bits value used when PrefixFrom is
-// outside the range of a uint8. It's returned as the int -1 in the
-// public API.
-const invalidPrefixBits = -1
-
// PrefixFrom returns a Prefix with the provided IP address and bit
// prefix length.
//
@@ -1258,13 +1249,14 @@
// If bits is less than zero or greater than ip.BitLen, Prefix.Bits
// will return an invalid value -1.
func PrefixFrom(ip Addr, bits int) Prefix {
- if bits < 0 || bits > ip.BitLen() {
- bits = invalidPrefixBits
+ if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
+ bits++
+ } else {
+ bits = 0
}
- b16 := int16(bits)
return Prefix{
- ip: ip.withoutZone(),
- bits: b16,
+ ip: ip.withoutZone(),
+ bitsPlusOne: uint8(bits),
}
}
@@ -1274,17 +1266,17 @@
// Bits returns p's prefix length.
//
// It reports -1 if invalid.
-func (p Prefix) Bits() int { return int(p.bits) }
+func (p Prefix) Bits() int { return int(p.bitsPlusOne) - 1 }
// IsValid reports whether p.Bits() has a valid range for p.Addr().
// If p.Addr() is the zero Addr, IsValid returns false.
// Note that if p is the zero Prefix, then p.IsValid() == false.
-func (p Prefix) IsValid() bool { return !p.ip.isZero() && p.bits >= 0 && int(p.bits) <= p.ip.BitLen() }
+func (p Prefix) IsValid() bool { return p.bitsPlusOne > 0 }
func (p Prefix) isZero() bool { return p == Prefix{} }
// IsSingleIP reports whether p contains exactly one IP.
-func (p Prefix) IsSingleIP() bool { return p.bits != 0 && int(p.bits) == p.ip.BitLen() }
+func (p Prefix) IsSingleIP() bool { return p.IsValid() && int(p.Bits()) == p.ip.BitLen() }
// ParsePrefix parses s as an IP address prefix.
// The string can be in the form "192.168.1.0/24" or "2001:db8::/32",
@@ -1337,10 +1329,8 @@
//
// If p is zero or otherwise invalid, Masked returns the zero Prefix.
func (p Prefix) Masked() Prefix {
- if m, err := p.ip.Prefix(int(p.bits)); err == nil {
- return m
- }
- return Prefix{}
+ m, _ := p.ip.Prefix(p.Bits())
+ return m
}
// Contains reports whether the network p includes ip.
@@ -1366,12 +1356,12 @@
// the compiler doesn't know that, so mask with 63 to help it.
// Now truncate to 32 bits, because this is IPv4.
// If all the bits we care about are equal, the result will be zero.
- return uint32((ip.addr.lo^p.ip.addr.lo)>>((32-p.bits)&63)) == 0
+ return uint32((ip.addr.lo^p.ip.addr.lo)>>((32-p.Bits())&63)) == 0
} else {
// xor the IP addresses together.
// Mask away the bits we don't care about.
// If all the bits we care about are equal, the result will be zero.
- return ip.addr.xor(p.ip.addr).and(mask6(int(p.bits))).isZero()
+ return ip.addr.xor(p.ip.addr).and(mask6(p.Bits())).isZero()
}
}
@@ -1390,11 +1380,11 @@
if p.ip.Is4() != o.ip.Is4() {
return false
}
- var minBits int16
- if p.bits < o.bits {
- minBits = p.bits
+ var minBits int
+ if p.Bits() < o.Bits() {
+ minBits = p.Bits()
} else {
- minBits = o.bits
+ minBits = o.Bits()
}
if minBits == 0 {
return true
@@ -1404,10 +1394,10 @@
// so the Prefix call on the one that's already minBits serves to zero
// out any remaining bits in IP.
var err error
- if p, err = p.ip.Prefix(int(minBits)); err != nil {
+ if p, err = p.ip.Prefix(minBits); err != nil {
return false
}
- if o, err = o.ip.Prefix(int(minBits)); err != nil {
+ if o, err = o.ip.Prefix(minBits); err != nil {
return false
}
return p.ip == o.ip
@@ -1437,7 +1427,7 @@
}
b = append(b, '/')
- b = appendDecimal(b, uint8(p.bits))
+ b = appendDecimal(b, uint8(p.Bits()))
return b
}
@@ -1500,5 +1490,5 @@
if !p.IsValid() {
return "invalid Prefix"
}
- return p.ip.String() + "/" + itoa.Itoa(int(p.bits))
+ return p.ip.String() + "/" + itoa.Itoa(p.Bits())
}
diff --git a/src/net/netip/netip_pkg_test.go b/src/net/netip/netip_pkg_test.go
index 677f523..2c9a2e6 100644
--- a/src/net/netip/netip_pkg_test.go
+++ b/src/net/netip/netip_pkg_test.go
@@ -24,30 +24,36 @@
ipp Prefix
want bool
}{
- {Prefix{v4, -2}, false},
- {Prefix{v4, -1}, false},
- {Prefix{v4, 0}, true},
- {Prefix{v4, 32}, true},
- {Prefix{v4, 33}, false},
+ {PrefixFrom(v4, -2), false},
+ {PrefixFrom(v4, -1), false},
+ {PrefixFrom(v4, 0), true},
+ {PrefixFrom(v4, 32), true},
+ {PrefixFrom(v4, 33), false},
- {Prefix{v6, -2}, false},
- {Prefix{v6, -1}, false},
- {Prefix{v6, 0}, true},
- {Prefix{v6, 32}, true},
- {Prefix{v6, 128}, true},
- {Prefix{v6, 129}, false},
+ {PrefixFrom(v6, -2), false},
+ {PrefixFrom(v6, -1), false},
+ {PrefixFrom(v6, 0), true},
+ {PrefixFrom(v6, 32), true},
+ {PrefixFrom(v6, 128), true},
+ {PrefixFrom(v6, 129), false},
- {Prefix{Addr{}, -2}, false},
- {Prefix{Addr{}, -1}, false},
- {Prefix{Addr{}, 0}, false},
- {Prefix{Addr{}, 32}, false},
- {Prefix{Addr{}, 128}, false},
+ {PrefixFrom(Addr{}, -2), false},
+ {PrefixFrom(Addr{}, -1), false},
+ {PrefixFrom(Addr{}, 0), false},
+ {PrefixFrom(Addr{}, 32), false},
+ {PrefixFrom(Addr{}, 128), false},
}
for _, tt := range tests {
got := tt.ipp.IsValid()
if got != tt.want {
t.Errorf("(%v).IsValid() = %v want %v", tt.ipp, got, tt.want)
}
+
+ // Test that there is only one invalid Prefix representation per Addr.
+ invalid := PrefixFrom(tt.ipp.Addr(), -1)
+ if !got && tt.ipp != invalid {
+ t.Errorf("(%v == %v) = false, want true", tt.ipp, invalid)
+ }
}
}
@@ -167,11 +173,11 @@
{mustPrefix("::1/0"), Addr{}, false},
{mustPrefix("1.2.3.4/0"), Addr{}, false},
// invalid Prefix
- {Prefix{mustIP("::1"), 129}, mustIP("::1"), false},
- {Prefix{mustIP("1.2.3.4"), 33}, mustIP("1.2.3.4"), false},
- {Prefix{Addr{}, 0}, mustIP("1.2.3.4"), false},
- {Prefix{Addr{}, 32}, mustIP("1.2.3.4"), false},
- {Prefix{Addr{}, 128}, mustIP("::1"), false},
+ {PrefixFrom(mustIP("::1"), 129), mustIP("::1"), false},
+ {PrefixFrom(mustIP("1.2.3.4"), 33), mustIP("1.2.3.4"), false},
+ {PrefixFrom(Addr{}, 0), mustIP("1.2.3.4"), false},
+ {PrefixFrom(Addr{}, 32), mustIP("1.2.3.4"), false},
+ {PrefixFrom(Addr{}, 128), mustIP("::1"), false},
// wrong IP family
{mustPrefix("::1/0"), mustIP("1.2.3.4"), false},
{mustPrefix("1.2.3.4/0"), mustIP("::1"), false},
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:12:49 PM8/20/22
to goph...@pubsubhelper.golang.org, golang-co...@googlegroups.com
Joseph Tsai uploaded patch set #2 to this change.
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to also be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
This simplifies IsValid to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 71 insertions(+), 55 deletions(-)
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:15:38 PM8/20/22
to goph...@pubsubhelper.golang.org, golang-co...@googlegroups.com
Joseph Tsai uploaded patch set #3 to this change.
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to also be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
IsValid is simplified to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 71 insertions(+), 55 deletions(-)
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:19:03 PM8/20/22
to goph...@pubsubhelper.golang.org, golang-co...@googlegroups.com
Joseph Tsai uploaded patch set #4 to this change.
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to also be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
IsValid is simplified to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 70 insertions(+), 55 deletions(-)
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:20:13 PM8/20/22
to goph...@pubsubhelper.golang.org, Brad Fitzpatrick, Ian Lance Taylor, Damien Neil, Gopher Robot, golang-co...@googlegroups.com
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Patch set 4:Run-TryBot +1Auto-Submit +1
Joseph Tsai (Gerrit)
Aug 20, 2022, 3:24:47 PM8/20/22
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1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1253:
if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {If bits is invalid, it is debatable whether we should even preserve the Addr.
This CL currently preserves the Addr (as did the old behavior).An argument for dropping a valid Addr for invalid bits is that String, (Un)MarshalText, and (Un)MarshalBinary does not preserve the Addr round-trip.
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:28:28 PM8/20/22
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1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1253:
if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
If bits is invalid, it is debatable whether we should even preserve the Addr. […]
Some related discussion on https://github.com/inetaf/netaddr/issues/169
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Joseph Tsai (Gerrit)
Aug 20, 2022, 3:38:40 PM8/20/22
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1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1253:
if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
Some related discussion on https://github. […]
BTW, this CL is not blocked on figuring this out. Whatever we do, we'll want to be consistent in behavior for both Prefix and AddrPort.
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Ian Lance Taylor (Gerrit)
Jan 23, 2023, 7:19:03 PM1/23/23
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Patch set 4:Code-Review +2
1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1383:
if p.Bits() < o.Bits() {if pb, ob := p.Bits(), o.Bits(); pb < ob {
minBits = pb
else {
minBits = ob
}
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Ian Lance Taylor (Gerrit)
Jan 23, 2023, 7:19:13 PM1/23/23
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Patch set 4:Code-Review +1
Joseph Tsai (Gerrit)
Jan 24, 2023, 3:38:13 PM1/24/23
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Joseph Tsai uploaded patch set #5 to this change.
The following approvals got outdated and were removed: Auto-Submit+1 by Joseph Tsai, Run-TryBot+1 by Joseph Tsai, TryBot-Result+1 by Gopher Robot
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
IsValid is simplified to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 70 insertions(+), 55 deletions(-)
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Joseph Tsai (Gerrit)
Jan 24, 2023, 3:38:46 PM1/24/23
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Patch set 6:Run-TryBot +1Auto-Submit +1
1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1383:
if p.Bits() < o.Bits() {
if pb, ob := p.Bits(), o.Bits(); pb < ob { […]
Done
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Joseph Tsai (Gerrit)
Jan 24, 2023, 3:40:42 PM1/24/23
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Joseph Tsai uploaded patch set #7 to this change.
The following approvals got outdated and were removed: Auto-Submit+1 by Joseph Tsai, Run-TryBot+1 by Joseph Tsai
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
IsValid is simplified to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 70 insertions(+), 55 deletions(-)
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Joseph Tsai (Gerrit)
Jan 24, 2023, 3:40:55 PM1/24/23
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Patch set 7:Run-TryBot +1Auto-Submit +1
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Joseph Tsai (Gerrit)
Feb 2, 2023, 6:28:46 AM2/2/23
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1 comment:
File src/net/netip/netip.go:
Patch Set #4, Line 1253:
if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {BTW, this CL is not blocked on figuring this out. […]
Ack
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Michael Knyszek (Gerrit)
Feb 2, 2023, 10:37:11 AM2/2/23
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Patch set 7:Code-Review +1
Gopher Robot (Gerrit)
Feb 2, 2023, 10:37:24 AM2/2/23
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Gopher Robot submitted this change.
4 is the latest approved patch-set.
The change was submitted with unreviewed changes in the following files:
```
The name of the file: src/net/netip/netip.go
Insertions: 4, Deletions: 4.
The diff is too large to show. Please review the diff.
```
Approvals:
Ian Lance Taylor: Looks good to me, but someone else must approve
Joseph Tsai: Run TryBots; Automatically submit change
Ian Lance Taylor: Looks good to me, approved
Michael Knyszek: Looks good to me, but someone else must approve
Gopher Robot: TryBots succeeded
net/netip: fix invalid representation of Prefix
For a given Addr, ensure there is exactly one invalid representation.
This allows invalid representations to be safely comparable.
To ensure that the zero value of Prefix is invalid,
we modify the encoding of bits to simply be the bit count plus one.
Since Addr is immutable, we check in the PrefixFrom constructor that
the provided Addr is valid and only store a non-zero bits length if so.
IsValid is simplified to just checking whether bitsPlusOne is non-zero.
Fixes #54525
Change-Id: I9244cae2fd160cc9c81d007866992df2e422d3b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/425035
Run-TryBot: Joseph Tsai <joe...@digital-static.net>
Reviewed-by: Michael Knyszek <mkny...@google.com>
Reviewed-by: Ian Lance Taylor <ia...@golang.org>
TryBot-Result: Gopher Robot <go...@golang.org>
Reviewed-by: Ian Lance Taylor <ia...@google.com>
Auto-Submit: Joseph Tsai <joe...@digital-static.net>
---
M src/net/netip/netip.go
M src/net/netip/netip_pkg_test.go
2 files changed, 77 insertions(+), 55 deletions(-)
diff --git a/src/net/netip/netip.go b/src/net/netip/netip.go
index ec9266d..aa700f4 100644
--- a/src/net/netip/netip.go
+++ b/src/net/netip/netip.go
@@ -1225,20 +1225,11 @@
type Prefix struct {
ip Addr
- // bits is logically a uint8 (storing [0,128]) but also
- // encodes an "invalid" bit, currently represented by the
- // invalidPrefixBits sentinel value. It could be packed into
- // the uint8 more with more complicated expressions in the
- // accessors, but the extra byte (in padding anyway) doesn't
- // hurt and simplifies code below.
- bits int16
+ // bitsPlusOne stores the prefix bit length plus one.
+ // A Prefix is valid if and only if bitsPlusOne is non-zero.
+ bitsPlusOne uint8
}
-// invalidPrefixBits is the Prefix.bits value used when PrefixFrom is
-// outside the range of a uint8. It's returned as the int -1 in the
-// public API.
-const invalidPrefixBits = -1
-
// PrefixFrom returns a Prefix with the provided IP address and bit
// prefix length.
//
@@ -1248,13 +1239,13 @@
// If bits is less than zero or greater than ip.BitLen, Prefix.Bits
// will return an invalid value -1.
func PrefixFrom(ip Addr, bits int) Prefix {
- if bits < 0 || bits > ip.BitLen() {
- bits = invalidPrefixBits
+ var bitsPlusOne uint8
+ if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
+ bitsPlusOne = uint8(bits) + 1
}
- b16 := int16(bits)
return Prefix{
- ip: ip.withoutZone(),
- bits: b16,
+ ip: ip.withoutZone(),
+ bitsPlusOne: bitsPlusOne,
}
}
@@ -1264,17 +1255,17 @@
// Bits returns p's prefix length.
//
// It reports -1 if invalid.
-func (p Prefix) Bits() int { return int(p.bits) }
+func (p Prefix) Bits() int { return int(p.bitsPlusOne) - 1 }
// IsValid reports whether p.Bits() has a valid range for p.Addr().
// If p.Addr() is the zero Addr, IsValid returns false.
// Note that if p is the zero Prefix, then p.IsValid() == false.
-func (p Prefix) IsValid() bool { return !p.ip.isZero() && p.bits >= 0 && int(p.bits) <= p.ip.BitLen() }
+func (p Prefix) IsValid() bool { return p.bitsPlusOne > 0 }
func (p Prefix) isZero() bool { return p == Prefix{} }
// IsSingleIP reports whether p contains exactly one IP.
-func (p Prefix) IsSingleIP() bool { return p.bits != 0 && int(p.bits) == p.ip.BitLen() }
+func (p Prefix) IsSingleIP() bool { return p.IsValid() && p.Bits() == p.ip.BitLen() }
// ParsePrefix parses s as an IP address prefix.
// The string can be in the form "192.168.1.0/24" or "2001:db8::/32",
@@ -1327,10 +1318,8 @@
//
// If p is zero or otherwise invalid, Masked returns the zero Prefix.
func (p Prefix) Masked() Prefix {
- if m, err := p.ip.Prefix(int(p.bits)); err == nil {
- return m
- }
- return Prefix{}
+ m, _ := p.ip.Prefix(p.Bits())
+ return m
}
// Contains reports whether the network p includes ip.
@@ -1356,12 +1345,12 @@
// the compiler doesn't know that, so mask with 63 to help it.
// Now truncate to 32 bits, because this is IPv4.
// If all the bits we care about are equal, the result will be zero.
- return uint32((ip.addr.lo^p.ip.addr.lo)>>((32-p.bits)&63)) == 0
+ return uint32((ip.addr.lo^p.ip.addr.lo)>>((32-p.Bits())&63)) == 0
} else {
// xor the IP addresses together.
// Mask away the bits we don't care about.
// If all the bits we care about are equal, the result will be zero.
- return ip.addr.xor(p.ip.addr).and(mask6(int(p.bits))).isZero()
+ return ip.addr.xor(p.ip.addr).and(mask6(p.Bits())).isZero()
}
}
@@ -1380,11 +1369,11 @@
if p.ip.Is4() != o.ip.Is4() {
return false
}
- var minBits int16
- if p.bits < o.bits {
- minBits = p.bits
+ var minBits int
+ if pb, ob := p.Bits(), o.Bits(); pb < ob {
+ minBits = pb
} else {
- minBits = o.bits
+ minBits = ob
}
if minBits == 0 {
return true
@@ -1394,10 +1383,10 @@
// so the Prefix call on the one that's already minBits serves to zero
// out any remaining bits in IP.
var err error
- if p, err = p.ip.Prefix(int(minBits)); err != nil {
+ if p, err = p.ip.Prefix(minBits); err != nil {
return false
}
- if o, err = o.ip.Prefix(int(minBits)); err != nil {
+ if o, err = o.ip.Prefix(minBits); err != nil {
return false
}
return p.ip == o.ip
@@ -1427,7 +1416,7 @@
}
b = append(b, '/')
- b = appendDecimal(b, uint8(p.bits))
+ b = appendDecimal(b, uint8(p.Bits()))
return b
}
@@ -1490,5 +1479,5 @@To view, visit change 425035. To unsubscribe, or for help writing mail filters, visit settings.
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