mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 03:27:39 +00:00
c995838e5c
- Clean up sigaction() code - Add a port scanner example - Introduce a ParseCidr() API - Clean up our futex abstraction code - Fix a harmless integer overflow in ParseIp() - Use kernel semaphores on NetBSD to make threads much faster
67 lines
3.1 KiB
C
67 lines
3.1 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2022 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/str/str.h"
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#include "net/http/ip.h"
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/**
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* Parse IPv4 network address.
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*
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* For example, a router address might be `10.10.10.1/24` in which case
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* the IP address word `0x0a0a0a01` would be returned, whose CIDR would
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* be 24. That means your IP address is on a network with 24 bits which
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* converts to a netmask `0xffffff00` by using `1u << (32 - res.cidr)`.
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* You may specify the IP address portion as an integer. As an example,
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* the value `168430081/1` would be the same as `10.10.10.1/1`
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*
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* @param n if -1 implies strlen
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* @return ip is uint32 IPv4 address, or -1 on failure
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* @return cidr is number of bits in network, on interval [1,32]; it
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* defaults to 32; if the return ip is -1 then cidr is undefined
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*/
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struct Cidr ParseCidr(const char *s, size_t n) {
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size_t i;
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const char *p;
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struct Cidr c;
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if (n == -1) n = s ? strlen(s) : 0;
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if ((p = strchr(s, '/'))) {
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if ((c.addr = ParseIp(s, (i = p - s))) != -1) {
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c.cidr = 0;
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for (++i; i < n; ++i) {
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if (isdigit(s[i])) {
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c.cidr *= 10;
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c.cidr += s[i] - '0';
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if (c.cidr > 32) {
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c.cidr = -1;
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break;
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}
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} else {
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c.cidr = -1;
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break;
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}
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}
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if (c.cidr <= 0) {
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c.addr = -1;
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}
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}
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} else {
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c.addr = ParseIp(s, n);
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c.cidr = 32;
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}
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return c;
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}
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