From eb8dd9dca1228af0cd132f515509051ecfabf6f6 Mon Sep 17 00:00:00 2001 From: cvs2svn Date: Mon, 14 Apr 2025 17:32:06 +0000 Subject: This commit was manufactured by cvs2git to create tag 'tb_20250414'. --- src/lib/libc/net/getnameinfo.3 | 264 ----------------------------------------- 1 file changed, 264 deletions(-) delete mode 100644 src/lib/libc/net/getnameinfo.3 (limited to 'src/lib/libc/net/getnameinfo.3') diff --git a/src/lib/libc/net/getnameinfo.3 b/src/lib/libc/net/getnameinfo.3 deleted file mode 100644 index 4e97b5d07b..0000000000 --- a/src/lib/libc/net/getnameinfo.3 +++ /dev/null @@ -1,264 +0,0 @@ -.\" $OpenBSD: getnameinfo.3,v 1.49 2022/09/11 06:38:10 jmc Exp $ -.\" $KAME: getnameinfo.3,v 1.37 2005/01/05 03:23:05 itojun Exp $ -.\" -.\" Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") -.\" Copyright (C) 2000, 2001 Internet Software Consortium. -.\" -.\" Permission to use, copy, modify, and distribute this software for any -.\" purpose with or without fee is hereby granted, provided that the above -.\" copyright notice and this permission notice appear in all copies. -.\" -.\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH -.\" REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY -.\" AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, -.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM -.\" LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE -.\" OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR -.\" PERFORMANCE OF THIS SOFTWARE. -.\" -.Dd $Mdocdate: September 11 2022 $ -.Dt GETNAMEINFO 3 -.Os -.Sh NAME -.Nm getnameinfo -.Nd socket address structure to hostname and service name -.Sh SYNOPSIS -.In sys/types.h -.In sys/socket.h -.In netdb.h -.Ft int -.Fn getnameinfo "const struct sockaddr *sa" "socklen_t salen" "char *host" \ - "size_t hostlen" "char *serv" "size_t servlen" "int flags" -.Sh DESCRIPTION -The -.Fn getnameinfo -function is used to convert a -.Vt sockaddr -structure to a pair of host name and service strings. -It is a replacement for and provides more flexibility than the -.Xr gethostbyaddr 3 -and -.Xr getservbyport 3 -functions and is the converse of the -.Xr getaddrinfo 3 -function. -.Pp -The -.Vt sockaddr -structure -.Fa sa -should point to either a -.Vt sockaddr_in -or -.Vt sockaddr_in6 -structure (for IPv4 or IPv6 respectively) that is -.Fa salen -bytes long. -.Pp -The host and service names associated with -.Fa sa -are stored in -.Fa host -and -.Fa serv -which have length parameters -.Fa hostlen -and -.Fa servlen . -The maximum value for -.Fa hostlen -is -.Dv NI_MAXHOST -and -the maximum value for -.Fa servlen -is -.Dv NI_MAXSERV , -as defined by -.In netdb.h . -If a length parameter is zero, no string will be stored. -Otherwise, enough space must be provided to store the -host name or service string plus a byte for the NUL terminator. -.Pp -The -.Fa flags -argument is formed by -.Tn OR Ns 'ing -the following values: -.Bl -tag -width "NI_NUMERICHOSTXX" -.It Dv NI_NOFQDN -A fully qualified domain name is not required for local hosts. -The local part of the fully qualified domain name is returned instead. -.It Dv NI_NUMERICHOST -Return the address in numeric form, as if calling -.Xr inet_ntop 3 , -instead of a host name. -.It Dv NI_NAMEREQD -A name is required. -If the host name cannot be found in DNS and this flag is set, -a non-zero error code is returned. -If the host name is not found and the flag is not set, the -address is returned in numeric form. -.It NI_NUMERICSERV -The service name is returned as a digit string representing the port number. -.It NI_DGRAM -Specifies that the service being looked up is a datagram -service, and causes -.Xr getservbyport 3 -to be called with a second argument of -.Dq udp -instead of its default of -.Dq tcp . -This is required for the few ports (512\-514) that have different services -for -.Tn UDP -and -.Tn TCP . -.El -.Pp -This implementation allows numeric IPv6 address notation with scope identifier, -as documented in RFC 4007. -IPv6 link-local address will appear as a string like -.Dq Li fe80::1%ne0 . -Refer to -.Xr getaddrinfo 3 -for more information. -.Sh RETURN VALUES -.Fn getnameinfo -returns zero on success or one of the error codes listed in -.Xr gai_strerror 3 -if an error occurs. -.Sh EXAMPLES -The following code tries to get a numeric host name, and service name, -for a given socket address. -Observe that there is no hardcoded reference to a particular address family. -.Bd -literal -offset indent -struct sockaddr *sa; /* input */ -char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; - -if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), sbuf, - sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV)) - errx(1, "could not get numeric hostname"); -printf("host=%s, serv=%s\en", hbuf, sbuf); -.Ed -.Pp -The following version checks if the socket address has a reverse address mapping: -.Bd -literal -offset indent -struct sockaddr *sa; /* input */ -char hbuf[NI_MAXHOST]; - -if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), NULL, 0, - NI_NAMEREQD)) - errx(1, "could not resolve hostname"); -printf("host=%s\en", hbuf); -.Ed -.Sh SEE ALSO -.Xr gai_strerror 3 , -.Xr getaddrinfo 3 , -.Xr gethostbyaddr 3 , -.Xr getservbyport 3 , -.Xr inet_ntop 3 , -.Xr res_init 3 , -.Xr hosts 5 , -.Xr resolv.conf 5 , -.Xr services 5 , -.Xr hostname 7 -.Rs -.%A Craig Metz -.%T Protocol Independence Using the Sockets API -.%B Proceedings of the Freenix Track: 2000 USENIX Annual Technical Conference -.%D June 2000 -.Re -.Sh STANDARDS -The -.Fn getnameinfo -function is defined by the -.St -p1003.1g-2000 -draft specification and documented in RFC 3493. -.Pp -.Rs -.%A R. Gilligan -.%A S. Thomson -.%A J. Bound -.%A J. McCann -.%A W. Stevens -.%D February 2003 -.%R RFC 3493 -.%T Basic Socket Interface Extensions for IPv6 -.Re -.Pp -.Rs -.%A S. Deering -.%A B. Haberman -.%A T. Jinmei -.%A E. Nordmark -.%A B. Zill -.%D March 2005 -.%R RFC 4007 -.%T IPv6 Scoped Address Architecture -.Re -.Sh CAVEATS -.Fn getnameinfo -can return both numeric and FQDN forms of the address specified in -.Fa sa . -There is no return value that indicates whether the string returned in -.Fa host -is a result of binary to numeric-text translation (like -.Xr inet_ntop 3 ) , -or is the result of a DNS reverse lookup. -Because of this, malicious parties could set up a PTR record as follows: -.Bd -literal -offset indent -1.0.0.127.in-addr.arpa. IN PTR 10.1.1.1 -.Ed -.Pp -and trick the caller of -.Fn getnameinfo -into believing that -.Fa sa -is -.Li 10.1.1.1 -when it is actually -.Li 127.0.0.1 . -.Pp -To prevent such attacks, the use of -.Dv NI_NAMEREQD -is recommended when the result of -.Fn getnameinfo -is used -for access control purposes: -.Bd -literal -offset indent -struct sockaddr *sa; -char addr[NI_MAXHOST]; -struct addrinfo hints, *res; -int error; - -error = getnameinfo(sa, sa->sa_len, addr, sizeof(addr), - NULL, 0, NI_NAMEREQD); -if (error == 0) { - memset(&hints, 0, sizeof(hints)); - hints.ai_socktype = SOCK_DGRAM; /*dummy*/ - hints.ai_flags = AI_NUMERICHOST; - if (getaddrinfo(addr, "0", &hints, &res) == 0) { - /* malicious PTR record */ - freeaddrinfo(res); - printf("bogus PTR record\en"); - return -1; - } - /* addr is FQDN as a result of PTR lookup */ -} else { - /* addr is numeric string */ - error = getnameinfo(sa, sa->sa_len, addr, sizeof(addr), - NULL, 0, NI_NUMERICHOST); -} -.Ed -.Sh BUGS -The implementation of -.Fn getnameinfo -is not thread-safe. -.Pp -.Ox -intentionally uses a different -.Dv NI_MAXHOST -value from what -.Tn "RFC 2553" -suggests, to avoid buffer length handling mistakes. -- cgit v1.2.3-55-g6feb