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Improve language and code examples.

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PR:             docs/24961
Submmitted by:  Tony Finch <dot@dotat.at>
This commit is contained in:
nik 2001-02-10 07:48:01 +00:00
parent 38719f8bca
commit 677b714f57
1 changed files with 41 additions and 31 deletions
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72
lib/libc/net/getaddrinfo.3
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@ -74,7 +74,7 @@ structure is defined as a result of including the
.Aq Pa netdb.h
header:
.Bd -literal -offset
struct addrinfo { *
struct addrinfo {
int ai_flags; /* AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST */
int ai_family; /* PF_xxx */
int ai_socktype; /* SOCK_xxx */
@ -272,17 +272,17 @@ from being called.
.Pp
The arguments to
.Fn getaddrinfo
must sufficiently be consistent and unambiguous.
Here are pitfall cases you may encounter:
must be sufficiently consistent and unambiguous.
Here are some problem cases you may encounter:
.Bl -bullet
.It
.Fn getaddrinfo
will raise error if members in
will fail if the members in the
.Fa hints
structure is not consistent.
structure are not consistent.
For example, for internet address families,
.Fn getaddrinfo
will raise error if you specify
will fail if you specify
.Dv SOCK_STREAM
to
.Fa ai_socktype
@ -296,10 +296,10 @@ If you specify a
which is defined only for certain
.Fa ai_socktype ,
.Fn getaddrinfo
will raise error because the arguments are not consistent.
will fail because the arguments are not consistent.
For example,
.Fn getaddrinfo
will raise error if you ask for
will return an error if you ask for
.Dq Li tftp
service on
.Dv SOCK_STREAM .
@ -311,7 +311,7 @@ while you set
to
.Dv SOCK_RAW ,
.Fn getaddrinfo
will raise error, because service names are not defined for the internet
will fail, because service names are not defined for the internet
.Dv SOCK_RAW
space.
.It
@ -323,7 +323,7 @@ and
.Fa ai_protocol
unspecified,
.Fn getaddrinfo
will raise error.
will fail.
This is because the numeric
.Fa servname
does not identify any socket type, and
@ -366,35 +366,37 @@ If the argument is not one of the
values, the function still returns a pointer to a string whose contents
indicate an unknown error.
.\"
.Sh EXTENSION
The implementation allows experimental numeric IPv6 address notation with
scope identifier.
By appending atmark and scope identifier to addresses, you can fill
.Sh EXTENSIONS
This implementation supports numeric IPv6 address notation with the
experimental scope identifier.
By appending a percent sign and scope identifier to the address, you
can specify the value of the
.Li sin6_scope_id
field for addresses.
This would make management of scoped address easier,
and allows cut-and-paste input of scoped address.
field of the socket address.
This makes management of scoped address easier,
and allows cut-and-paste input of scoped addresses.
.Pp
At this moment the code supports only link-local addresses with the format.
Scope identifier is hardcoded to name of hardware interface associated
with the link.
At the moment the code supports only link-local addresses in this format.
The scope identifier is hardcoded to name of hardware interface associated
with the link,
.Po
such as
.Li ne0
.Pc .
Example would be like
For example,
.Dq Li fe80::1%ne0 ,
which means
.Do
.Li fe80::1
on the link associated with
on the link associated with the
.Li ne0
interface
.Dc .
.Pp
The implementation is still very experimental and non-standard.
The current implementation assumes one-by-one relationship between
interface and link, which is not necessarily true from the specification.
This implementation is still very experimental and non-standard.
The current implementation assumes a one-to-one relationship between
interfaces and links, which is not necessarily true according to the
specification.
.\"
.Sh EXAMPLES
The following code tries to connect to
@ -402,11 +404,11 @@ The following code tries to connect to
service
.Dq Li http .
via stream socket.
It loops through all the addresses available, regardless from address family.
If the destination resolves to IPv4 address, it will use
It loops through all the addresses available, regardless of the address family.
If the destination resolves to an IPv4 address, it will use an
.Dv AF_INET
socket.
Similarly, if it resolves to IPv6,
Similarly, if it resolves to IPv6, an
.Dv AF_INET6
socket is used.
Observe that there is no hardcoded reference to particular address family.
@ -428,6 +430,8 @@ if (error) {
/*NOTREACHED*/
}
s = -1;
cause = "no addresses";
errno = EADDRNOTAVAIL;
for (res = res0; res; res = res->ai_next) {
s = socket(res->ai_family, res->ai_socktype,
res->ai_protocol);
@ -452,7 +456,7 @@ if (s < 0) {
freeaddrinfo(res0);
.Ed
.Pp
The following example tries to open wildcard listening socket onto service
The following example tries to open a wildcard listening socket onto service
.Dq Li http ,
for all the address families available.
.Bd -literal -offset indent
@ -480,12 +484,18 @@ for (res = res0; res && nsock < MAXSOCK; res = res->ai_next) {
continue;
}
if (connect(s[nsock], res->ai_addr, res->ai_addrlen) < 0) {
if (bind(s[nsock], res->ai_addr, res->ai_addrlen) < 0) {
cause = "connect";
close(s[nsock]);
continue;
}
if (listen(s[nsock], SOMAXCONN) < 0) {
cause = "listen";
close(s[nsock]);
continue;
}
nsock++;
}
if (nsock == 0) {
@ -547,7 +557,7 @@ System error returned in
.Va errno .
.El
.Pp
If called with proper argument,
If called with an appropriate argument,
.Fn gai_strerror
returns a pointer to a string describing the given error code.
If the argument is not one of the