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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:18:25 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:18:25 +0000 |
commit | 109be507377fe7f6e8819ac94041d3fdcdf6fd2f (patch) | |
tree | 2806a689f8fab4a2ec9fc949830ef270a91d667d /src/net/port.go | |
parent | Initial commit. (diff) | |
download | golang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.tar.xz golang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.zip |
Adding upstream version 1.19.8.upstream/1.19.8upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/net/port.go')
-rw-r--r-- | src/net/port.go | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/net/port.go b/src/net/port.go new file mode 100644 index 0000000..32e7628 --- /dev/null +++ b/src/net/port.go @@ -0,0 +1,62 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package net + +// parsePort parses service as a decimal integer and returns the +// corresponding value as port. It is the caller's responsibility to +// parse service as a non-decimal integer when needsLookup is true. +// +// Some system resolvers will return a valid port number when given a number +// over 65536 (see https://golang.org/issues/11715). Alas, the parser +// can't bail early on numbers > 65536. Therefore reasonably large/small +// numbers are parsed in full and rejected if invalid. +func parsePort(service string) (port int, needsLookup bool) { + if service == "" { + // Lock in the legacy behavior that an empty string + // means port 0. See golang.org/issue/13610. + return 0, false + } + const ( + max = uint32(1<<32 - 1) + cutoff = uint32(1 << 30) + ) + neg := false + if service[0] == '+' { + service = service[1:] + } else if service[0] == '-' { + neg = true + service = service[1:] + } + var n uint32 + for _, d := range service { + if '0' <= d && d <= '9' { + d -= '0' + } else { + return 0, true + } + if n >= cutoff { + n = max + break + } + n *= 10 + nn := n + uint32(d) + if nn < n || nn > max { + n = max + break + } + n = nn + } + if !neg && n >= cutoff { + port = int(cutoff - 1) + } else if neg && n > cutoff { + port = int(cutoff) + } else { + port = int(n) + } + if neg { + port = -port + } + return port, false +} |