mirror of
https://github.com/zerotier/toss.git
synced 2026-05-22 16:21:50 -07:00
Adam Ierymenko
70 lines
2.7 KiB
C
70 lines
2.7 KiB
C
/* (c)2017 ZeroTier, Inc. (Adam Ierymenko) -- MIT LICENSE */
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#ifndef TOSS_IPSCOPE_H
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#define TOSS_IPSCOPE_H
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#include <stdint.h>
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enum toss_ip_scope
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{
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IP_SCOPE_NONE, /* NULL or not an IP address */
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IP_SCOPE_MULTICAST, /* 224.0.0.0 and other V4/V6 multicast IPs */
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IP_SCOPE_LOOPBACK, /* 127.0.0.1, ::1, etc. */
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IP_SCOPE_GLOBAL, /* globally routable IP address (all others) */
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IP_SCOPE_LINK_LOCAL, /* 169.254.x.x, IPv6 LL */
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IP_SCOPE_SHARED, /* 100.64.0.0/10, shared space for e.g. carrier-grade NAT */
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IP_SCOPE_PRIVATE /* 10.x.x.x, 192.168.x.x, etc. */
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};
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static enum toss_ip_scope classify_ip4(const struct sockaddr_in *in)
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{
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const uint32_t ip = (uint32_t)ntohl(in->sin_addr.s_addr);
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switch(ip >> 24) {
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case 0x00: return IP_SCOPE_NONE; // 0.0.0.0/8 (reserved, never used)
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case 0x0a: return IP_SCOPE_PRIVATE; // 10.0.0.0/8
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case 0x64:
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if ((ip & 0xffc00000) == 0x64400000) return IP_SCOPE_SHARED; // 100.64.0.0/10
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break;
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case 0x7f: return IP_SCOPE_LOOPBACK; // 127.0.0.0/8
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case 0xa9:
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if ((ip & 0xffff0000) == 0xa9fe0000) return IP_SCOPE_LINK_LOCAL; // 169.254.0.0/16
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break;
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case 0xac:
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if ((ip & 0xfff00000) == 0xac100000) return IP_SCOPE_PRIVATE; // 172.16.0.0/12
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break;
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case 0xc0:
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if ((ip & 0xffff0000) == 0xc0a80000) return IP_SCOPE_PRIVATE; // 192.168.0.0/16
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break;
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case 0xff: return IP_SCOPE_NONE; // 255.0.0.0/8 (broadcast, or unused/unusable)
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}
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switch(ip >> 28) {
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case 0xe: return IP_SCOPE_MULTICAST; // 224.0.0.0/4
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}
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return IP_SCOPE_GLOBAL;
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}
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static enum toss_ip_scope classify_ip6(const struct sockaddr_in6 *in)
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{
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const uint8_t *ip = (const uint8_t *)in->sin6_addr.s6_addr;
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if ((ip[0] & 0xf0) == 0xf0) {
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if (ip[0] == 0xff) return IP_SCOPE_MULTICAST; // ff00::/8
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if ((ip[0] == 0xfe)&&((ip[1] & 0xc0) == 0x80)) {
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unsigned int k = 2;
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while ((!ip[k])&&(k < 15)) ++k;
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if ((k == 15)&&(ip[15] == 0x01))
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return IP_SCOPE_LOOPBACK; // fe80::1/128
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else return IP_SCOPE_LINK_LOCAL; // fe80::/10
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}
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if ((ip[0] & 0xfe) == 0xfc) return IP_SCOPE_PRIVATE; // fc00::/7
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}
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unsigned int k = 0;
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while ((!ip[k])&&(k < 15)) ++k;
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if (k == 15) { // all 0's except last byte
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if (ip[15] == 0x01) return IP_SCOPE_LOOPBACK; // ::1/128
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if (ip[15] == 0x00) return IP_SCOPE_NONE; // ::/128
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}
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return IP_SCOPE_GLOBAL;
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}
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#endif
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