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32 .\" From: @(#)rcmd.3 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/net/rcmd.3,v 1.12.2.8 2001/12/14 18:33:55 ru Exp $
34 .\" $DragonFly: src/lib/libc/net/rcmd.3,v 1.4 2007/11/23 23:16:36 swildner Exp $
47 .Nd routines for returning a stream to a remote command
53 .Fn rcmd "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "int *fd2p"
55 .Fn rresvport "int *port"
57 .Fn iruserok "u_long raddr" "int superuser" "const char *ruser" "const char *luser"
59 .Fn ruserok "const char *rhost" "int superuser" "const char *ruser" "const char *luser"
61 .Fn rcmd_af "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "int *fd2p" "int af"
63 .Fn rresvport_af "int *port" "int af"
65 .Fn iruserok_sa "const void *addr" "int addrlen" "int superuser" "const char *ruser" "const char *luser"
70 is used by the super-user to execute a command on
71 a remote machine using an authentication scheme based
72 on reserved port numbers.
76 returns a descriptor to a socket
77 with an address in the privileged port space.
82 to authenticate clients requesting service with
84 All three functions are present in the same file and are used
87 server (among others).
96 returning -1 if the host does not exist.
99 is set to the standard name of the host
100 and a connection is established to a server
101 residing at the well-known Internet port
104 If the connection succeeds,
105 a socket in the Internet domain of type
107 is returned to the caller, and given to the remote
114 is non-zero, then an auxiliary channel to a control
115 process will be set up, and a descriptor for it will be placed
118 The control process will return diagnostic
119 output from the command (unit 2) on this channel, and will also
120 accept bytes on this channel as being
122 signal numbers, to be
123 forwarded to the process group of the command.
128 (unit 2 of the remote
129 command) will be made the same as the
132 provision is made for sending arbitrary signals to the remote process,
133 although you may be able to get its attention by using out-of-band data.
135 The protocol is described in detail in
140 function is used to obtain a socket to which an address with a Privileged
141 Internet port is bound.
142 This socket is suitable for use by
144 and several other functions.
145 Privileged Internet ports are those in the range 0 to 1023.
146 Only the super-user is allowed to bind an address of this sort
153 functions take a remote host's IP address or name, as returned by the
155 routines, two user names and a flag indicating whether the local user's
156 name is that of the super-user.
159 the super-user, it checks the
162 If that lookup is not done, or is unsuccessful, the
164 in the local user's home directory is checked to see if the request for
167 If this file does not exist, is not a regular file, is owned by anyone
168 other than the user or the super-user, or is writable by anyone other
169 than the owner, the check automatically fails.
170 Zero is returned if the machine name is listed in the
172 file, or the host and remote user name are found in the
179 If the local domain (as obtained from
181 is the same as the remote domain, only the machine name need be specified.
185 function is strongly preferred for security reasons.
186 It requires trusting the local DNS at most, while the
188 function requires trusting the entire DNS, which can be spoofed.
190 The functions with an
199 work the same as the corresponding functions without a
200 suffix, except that they are capable of handling both IPv6 and IPv4 ports.
204 suffix means that the function has an additional
206 argument which is used to specify the address family,
210 argument extension is implemented for functions
211 that have no binary address argument.
214 argument specifies which address family is desired.
218 suffix means that the function has general socket address and
220 As the socket address is a protocol independent data structure,
221 IPv4 and IPv6 socket address can be passed as desired.
224 argument extension is implemented for functions
225 that pass a protocol dependent binary address argument.
226 The argument needs to be replaced with a more general address structure
227 to support multiple address families in a general way.
229 The functions with neither an
233 suffix work for IPv4 only, except for
235 which can handle both IPv6 and IPv4.
236 To switch the address family, the
238 argument must be filled with
250 returns a valid socket descriptor on success.
251 It returns -1 on error and prints a diagnostic message
252 on the standard error.
257 returns a valid, bound socket descriptor on success.
258 It returns -1 on error with the global value
260 set according to the reason for failure.
263 is overloaded to mean ``All network ports in use.''
276 .%T "Advanced Socket API for IPv6"
283 .%T "Advanced Socket API for IPv6"
284 .%O draft-ietf-ipngwg-rfc2292bis-01.txt
288 functions appeared in
291 appeared in RFC 2292, and was implemented by the WIDE project
292 for the Hydrangea IPv6 protocol stack kit.
294 appeared in draft-ietf-ipngwg-rfc2292bis-01.txt,
295 and was implemented in the WIDE/KAME IPv6 protocol stack kit.
297 appeared in discussion on the IETF ipngwg mailing list,
298 and was implemented in