diff options
Diffstat (limited to 'lib/libc/net/getnameinfo.c')
| -rw-r--r-- | lib/libc/net/getnameinfo.c | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/lib/libc/net/getnameinfo.c b/lib/libc/net/getnameinfo.c new file mode 100644 index 000000000000..01bceaa98fce --- /dev/null +++ b/lib/libc/net/getnameinfo.c @@ -0,0 +1,554 @@ +/* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */ + +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * Copyright (c) 2000 Ben Harris. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Issues to be discussed: + * - Thread safe-ness must be checked + * - RFC2553 says that we should raise error on short buffer. X/Open says + * we need to truncate the result. We obey RFC2553 (and X/Open should be + * modified). ipngwg rough consensus seems to follow RFC2553. + * - What is "local" in NI_FQDN? + * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. + * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if + * sin6_scope_id is filled - standardization status? + * XXX breaks backward compat for code that expects no scopeid. + * beware on merge. + */ + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <net/if.h> +#include <net/if_dl.h> +#include <net/if_types.h> +#include <net/firewire.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> +#include <netdb.h> +#include <resolv.h> +#include <string.h> +#include <stddef.h> +#include <errno.h> + +static const struct afd *find_afd(int); +static int getnameinfo_inet(const struct afd *, + const struct sockaddr *, socklen_t, char *, + size_t, char *, size_t, int); +#ifdef INET6 +static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, + size_t, int); +static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); +#endif +static int getnameinfo_link(const struct afd *, + const struct sockaddr *, socklen_t, char *, + size_t, char *, size_t, int); +static int hexname(const u_int8_t *, size_t, char *, size_t); +static int getnameinfo_un(const struct afd *, + const struct sockaddr *, socklen_t, char *, + size_t, char *, size_t, int); + +static const struct afd { + int a_af; + size_t a_addrlen; + socklen_t a_socklen; + int a_off; + int (*a_func)(const struct afd *, + const struct sockaddr *, socklen_t, char *, + size_t, char *, size_t, int); +} afdl [] = { +#ifdef INET6 + {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), + offsetof(struct sockaddr_in6, sin6_addr), + getnameinfo_inet}, +#endif + {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), + offsetof(struct sockaddr_in, sin_addr), + getnameinfo_inet}, +#define sizeofmember(type, member) (sizeof(((type *)0)->member)) + {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), + sizeof(struct sockaddr_un), + offsetof(struct sockaddr_un, sun_path), + getnameinfo_un}, + {PF_LINK, sizeofmember(struct sockaddr_dl, sdl_data), + sizeof(struct sockaddr_dl), + offsetof(struct sockaddr_dl, sdl_data), + getnameinfo_link}, + {0, 0, 0}, +}; + +int +getnameinfo(const struct sockaddr *sa, socklen_t salen, + char *host, size_t hostlen, char *serv, size_t servlen, + int flags) +{ + const struct afd *afd; + + if (sa == NULL) + return (EAI_FAIL); + + afd = find_afd(sa->sa_family); + if (afd == NULL) + return (EAI_FAMILY); + /* + * getnameinfo() accepts an salen of sizeof(struct sockaddr_storage) + * at maximum as shown in RFC 4038 Sec.6.2.3. + */ + if (salen > sizeof(struct sockaddr_storage)) + return (EAI_FAMILY); + + switch (sa->sa_family) { + case PF_LOCAL: + /* + * PF_LOCAL uses variable salen depending on the + * content length of sun_path. Require 1 byte in + * sun_path at least. + */ + if (salen <= afd->a_socklen - + sizeofmember(struct sockaddr_un, sun_path)) + return (EAI_FAMILY); + else if (salen > afd->a_socklen) + salen = afd->a_socklen; + break; + case PF_LINK: + if (salen <= afd->a_socklen - + sizeofmember(struct sockaddr_dl, sdl_data)) + return (EAI_FAMILY); + break; + default: + if (salen < afd->a_socklen) + return (EAI_FAMILY); + else + salen = afd->a_socklen; + break; + } + + return ((*afd->a_func)(afd, sa, salen, host, hostlen, + serv, servlen, flags)); +} + +static const struct afd * +find_afd(int af) +{ + const struct afd *afd; + + if (af == PF_UNSPEC) + return (NULL); + for (afd = &afdl[0]; afd->a_af > 0; afd++) { + if (afd->a_af == af) + return (afd); + } + return (NULL); +} + +static int +getnameinfo_inet(const struct afd *afd, + const struct sockaddr *sa, socklen_t salen, + char *host, size_t hostlen, char *serv, size_t servlen, + int flags) +{ + struct servent *sp; + struct hostent *hp; + u_short port; + const char *addr; + u_int32_t v4a; + int h_error; + char numserv[512]; + char numaddr[512]; + + /* network byte order */ + port = ((const struct sockaddr_in *)sa)->sin_port; + addr = (const char *)sa + afd->a_off; + + if (serv == NULL || servlen == 0) { + /* + * do nothing in this case. + * in case you are wondering if "&&" is more correct than + * "||" here: rfc2553bis-03 says that serv == NULL OR + * servlen == 0 means that the caller does not want the result. + */ + } else { + if (flags & NI_NUMERICSERV) + sp = NULL; + else { + sp = getservbyport(port, + (flags & NI_DGRAM) ? "udp" : "tcp"); + } + if (sp) { + if (strlen(sp->s_name) + 1 > servlen) + return EAI_MEMORY; + strlcpy(serv, sp->s_name, servlen); + } else { + snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); + if (strlen(numserv) + 1 > servlen) + return EAI_MEMORY; + strlcpy(serv, numserv, servlen); + } + } + + switch (sa->sa_family) { + case AF_INET: + v4a = (u_int32_t) + ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); + if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a) || + IN_ZERONET(v4a)) + flags |= NI_NUMERICHOST; + break; +#ifdef INET6 + case AF_INET6: + { + const struct sockaddr_in6 *sin6; + + sin6 = (const struct sockaddr_in6 *)sa; + + /* + * https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnameinfo.html + * "[IP6] [Option Start] If the socket address structure + * contains an IPv4-mapped IPv6 address or an IPv4-compatible + * IPv6 address, the implementation shall extract the embedded + * IPv4 address and lookup the node name for that IPv4 address. + * [Option End]" + * => getipnodebyaddr() handles this case for us. + * => in case of NI_NUMERICHOST being set, inet_ntop[6] will + * handle it too. + * + * "If the address is the IPv6 unspecified address ( "::" ), + * a lookup shall not be performed and the behavior shall be + * the same as when the node's name cannot be located." + * => getipnodebyaddr() handles this case for us. + * => in case of NI_NUMERICHOST being set, + * ip6_parsenumeric() -> inet_ntop[6] will handle it too. + */ + + /* + * We used to exclude link-local from lookups. + * Even though calles in the resolver chain may not (yet) + * properly deal with them, we no longer do as for link-local + * there is a path to resolve these. See: + * RFC 6303 4.5. IPv6 Link-Local Addresses + * RFC 6762 4. Reverse Address Mapping + * + * XXX For IPv6 MC the only reference found was + * https://www.ietf.org/archive/id/draft-michaelson-as112-ipv6-02.html + * but there are also no "empty zone"s for x.0.f.f.ip6.arpa + * in DNS servers. Keep catching it here for now and + * do not attempt name resolution but return the address string. + */ + if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) + flags |= NI_NUMERICHOST; + } + break; +#endif + } + if (host == NULL || hostlen == 0) { + /* + * do nothing in this case. + * in case you are wondering if "&&" is more correct than + * "||" here: rfc2553bis-03 says that host == NULL or + * hostlen == 0 means that the caller does not want the result. + */ + } else if (flags & NI_NUMERICHOST) { + size_t numaddrlen; + + /* NUMERICHOST and NAMEREQD conflicts with each other */ + if (flags & NI_NAMEREQD) + return EAI_NONAME; + + switch(afd->a_af) { +#ifdef INET6 + case AF_INET6: + { + int error; + + if ((error = ip6_parsenumeric(sa, addr, host, + hostlen, flags)) != 0) + return(error); + break; + } +#endif + default: + if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) + == NULL) + return EAI_SYSTEM; + numaddrlen = strlen(numaddr); + if (numaddrlen + 1 > hostlen) /* don't forget terminator */ + return EAI_MEMORY; + strlcpy(host, numaddr, hostlen); + break; + } + } else { + hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); + + if (hp) { +#if 0 + /* + * commented out, since "for local host" is not + * implemented here - see RFC2553 p30 + */ + if (flags & NI_NOFQDN) { + char *p; + p = strchr(hp->h_name, '.'); + if (p) + *p = '\0'; + } +#endif + if (strlen(hp->h_name) + 1 > hostlen) { + freehostent(hp); + return EAI_MEMORY; + } + strlcpy(host, hp->h_name, hostlen); + freehostent(hp); + } else { + if (flags & NI_NAMEREQD) + return EAI_NONAME; + switch(afd->a_af) { +#ifdef INET6 + case AF_INET6: + { + int error; + + if ((error = ip6_parsenumeric(sa, addr, host, + hostlen, + flags)) != 0) + return(error); + break; + } +#endif + default: + if (inet_ntop(afd->a_af, addr, host, + hostlen) == NULL) + return EAI_SYSTEM; + break; + } + } + } + return(0); +} + +#ifdef INET6 +static int +ip6_parsenumeric(const struct sockaddr *sa, const char *addr, + char *host, size_t hostlen, int flags) +{ + size_t numaddrlen; + char numaddr[512]; + + if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) + return EAI_SYSTEM; + + numaddrlen = strlen(numaddr); + if (numaddrlen + 1 > hostlen) /* don't forget terminator */ + return EAI_OVERFLOW; + strlcpy(host, numaddr, hostlen); + + if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { + char zonebuf[MAXHOSTNAMELEN]; + int zonelen; + + zonelen = ip6_sa2str( + (const struct sockaddr_in6 *)(const void *)sa, + zonebuf, sizeof(zonebuf), flags); + if (zonelen < 0) + return EAI_OVERFLOW; + if (zonelen + 1 + numaddrlen + 1 > hostlen) + return EAI_OVERFLOW; + + /* construct <numeric-addr><delim><zoneid> */ + memcpy(host + numaddrlen + 1, zonebuf, + (size_t)zonelen); + host[numaddrlen] = SCOPE_DELIMITER; + host[numaddrlen + 1 + zonelen] = '\0'; + } + + return 0; +} + +/* ARGSUSED */ +static int +ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) +{ + unsigned int ifindex; + const struct in6_addr *a6; + int n; + + ifindex = (unsigned int)sa6->sin6_scope_id; + a6 = &sa6->sin6_addr; + + if ((flags & NI_NUMERICSCOPE) != 0) { + n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); + if (n < 0 || n >= bufsiz) + return -1; + else + return n; + } + + /* if_indextoname() does not take buffer size. not a good api... */ + if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || + IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { + char *p = if_indextoname(ifindex, buf); + if (p) { + return(strlen(p)); + } + } + + /* last resort */ + n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); + if (n < 0 || (size_t)n >= bufsiz) + return -1; + else + return n; +} +#endif /* INET6 */ + +/* + * getnameinfo_link(): + * Format a link-layer address into a printable format, paying attention to + * the interface type. + */ +/* ARGSUSED */ +static int +getnameinfo_link(const struct afd *afd, + const struct sockaddr *sa, socklen_t salen, + char *host, size_t hostlen, char *serv, size_t servlen, int flags) +{ + const struct sockaddr_dl *sdl = + (const struct sockaddr_dl *)(const void *)sa; + const struct fw_hwaddr *iha; + int n; + + if (serv != NULL && servlen > 0) + *serv = '\0'; + + if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { + n = snprintf(host, hostlen, "link#%d", sdl->sdl_index); + if (n >= hostlen) { + *host = '\0'; + return (EAI_MEMORY); + } + return (0); + } + + if (sdl->sdl_nlen > 0 && sdl->sdl_alen == 0) { + n = sdl->sdl_nlen; + if (n >= hostlen) { + *host = '\0'; + return (EAI_MEMORY); + } + memcpy(host, sdl->sdl_data, sdl->sdl_nlen); + host[n] = '\0'; + return (0); + } + + switch (sdl->sdl_type) { + case IFT_IEEE1394: + if (sdl->sdl_alen < sizeof(iha->sender_unique_ID_hi) + + sizeof(iha->sender_unique_ID_lo)) + return EAI_FAMILY; + iha = (const struct fw_hwaddr *)(const void *)LLADDR(sdl); + return hexname((const u_int8_t *)&iha->sender_unique_ID_hi, + sizeof(iha->sender_unique_ID_hi) + + sizeof(iha->sender_unique_ID_lo), + host, hostlen); + /* + * The following have zero-length addresses. + * IFT_GIF (net/if_gif.c) + * IFT_LOOP (net/if_loop.c) + * IFT_PPP (net/if_tuntap.c) + * IFT_SLIP (net/if_sl.c, net/if_strip.c) + * IFT_STF (net/if_stf.c) + * IFT_L2VLAN (net/if_vlan.c) + * IFT_BRIDGE (net/if_bridge.h> + */ + /* + * The following use IPv4 addresses as link-layer addresses: + * IFT_OTHER (net/if_gre.c) + * IFT_OTHER (netinet/ip_ipip.c) + */ + /* default below is believed correct for all these. */ + case IFT_ETHER: + case IFT_FDDI: + case IFT_HIPPI: + case IFT_ISO88025: + default: + return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, + host, hostlen); + } +} + +static int +hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen) +{ + int i, n; + char *outp = host; + + *outp = '\0'; + for (i = 0; i < len; i++) { + n = snprintf(outp, hostlen, "%s%02x", + i ? ":" : "", cp[i]); + if (n < 0 || n >= hostlen) { + *host = '\0'; + return EAI_MEMORY; + } + outp += n; + hostlen -= n; + } + return 0; +} + +/* + * getnameinfo_un(): + * Format a UNIX IPC domain address (pathname). + */ +/* ARGSUSED */ +static int +getnameinfo_un(const struct afd *afd, + const struct sockaddr *sa, socklen_t salen, + char *host, size_t hostlen, char *serv, size_t servlen, int flags) +{ + size_t pathlen; + + if (serv != NULL && servlen > 0) + *serv = '\0'; + if (host != NULL && hostlen > 0) { + pathlen = salen - afd->a_off; + + if (pathlen + 1 > hostlen) { + *host = '\0'; + return (EAI_MEMORY); + } + strlcpy(host, (const char *)sa + afd->a_off, pathlen + 1); + } + + return (0); +} |