mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 23:13:34 +00:00
248c6d54bb
Added necessary constants (DNS_TYPE_PTR, NI_NUMERICHOST etc.). Implementation of getnameinfo is similar to getaddrinfo, with internal functions: * ResolveDnsReverse: performs rDNS query and parses the PTR record * ResolveHostsReverse: reads /etc/hosts to map hostname to address Earlier, the HOSTS.txt would only need to be sorted at loading time, because the only kind of lookup was name -> address. Now since address -> name lookups are also possible, so the HostsTxt struct, the sorting method (and the related tests) was changed to reflect this.
107 lines
5 KiB
C
107 lines
5 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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│ This is free and unencumbered software released into the public domain. │
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│ │
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│ Anyone is free to copy, modify, publish, use, compile, sell, or │
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│ distribute this software, either in source code form or as a compiled │
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│ binary, for any purpose, commercial or non-commercial, and by any │
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│ means. │
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│ │
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│ In jurisdictions that recognize copyright laws, the author or authors │
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│ of this software dedicate any and all copyright interest in the │
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│ software to the public domain. We make this dedication for the benefit │
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│ of the public at large and to the detriment of our heirs and │
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│ successors. We intend this dedication to be an overt act of │
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│ relinquishment in perpetuity of all present and future rights to this │
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│ software under copyright law. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR │
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│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
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│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR │
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│ OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/safemacros.internal.h"
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#include "libc/calls/calls.h"
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#include "libc/dns/consts.h"
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#include "libc/dns/dns.h"
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#include "libc/dns/hoststxt.h"
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#include "libc/dns/resolvconf.h"
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#include "libc/fmt/conv.h"
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#include "libc/fmt/fmt.h"
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#include "libc/mem/mem.h"
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#include "libc/sock/sock.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/af.h"
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#include "libc/sysv/consts/inaddr.h"
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#include "libc/sysv/errfuns.h"
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/**
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* Resolves name/service for socket address.
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*
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* @param addr
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* @param addrlen
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* @param name
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* @param namelen
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* @param service
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* @param servicelen
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* @param flags
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*
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* @return 0 on success or EAI_xxx value
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*/
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int getnameinfo(const struct sockaddr *addr, socklen_t addrlen, char *name,
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socklen_t namelen, char *service, socklen_t servicelen,
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int flags) {
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char rdomain[1 + sizeof "255.255.255.255.in-addr.arpa"];
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char info[512];
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int rc, port;
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uint8_t *ip;
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unsigned int valid_flags;
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valid_flags =
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(NI_NAMEREQD | NI_NUMERICHOST | NI_NUMERICSERV | NI_NOFQDN | NI_DGRAM);
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if (flags & ~(valid_flags)) return EAI_BADFLAGS;
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if (!name && !service) return EAI_NONAME;
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if (addr->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
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return EAI_FAMILY;
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ip = (uint8_t *)&(((struct sockaddr_in *)addr)->sin_addr);
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sprintf(rdomain, "%d.%d.%d.%d.in-addr.arpa", ip[3], ip[2], ip[1], ip[0]);
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info[0] = '\0';
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if (name != NULL && namelen != 0) {
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if ((flags & NI_NUMERICHOST) && (flags & NI_NAMEREQD)) return EAI_NONAME;
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if ((flags & NI_NUMERICHOST) &&
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inet_ntop(AF_INET, ip, info, sizeof(info)) == NULL)
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return EAI_SYSTEM;
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else if (!info[0] && ResolveHostsReverse(GetHostsTxt(), AF_INET, ip, info,
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sizeof(info)) < 0)
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return EAI_SYSTEM;
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else if (!info[0] && ResolveDnsReverse(GetResolvConf(), AF_INET, rdomain,
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info, sizeof(info)) < 0)
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return EAI_SYSTEM;
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else if (!info[0] && (flags & NI_NAMEREQD))
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return EAI_NONAME;
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else if (!info[0] && inet_ntop(AF_INET, ip, info, sizeof(info)) == NULL)
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return EAI_SYSTEM;
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if (strlen(info) + 1 > namelen) return EAI_OVERFLOW;
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strcpy(name, info);
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}
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port = ntohs(((struct sockaddr_in *)addr)->sin_port);
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info[0] = '\0';
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if (service != NULL && servicelen != 0) {
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itoa(port, info, 10);
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/* TODO: reverse lookup on /etc/services to get name of service */
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if (strlen(info) + 1 > servicelen) return EAI_OVERFLOW;
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strcpy(service, info);
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}
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return 0;
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}
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