--- libevent-1.4.14b-stable/evdns.3	st lis 25 07:55:34 2009

+++ libevent-1.4.14b-stable/evdns.3	po lis 21 09:31:22 2011

@@ -25,66 +25,67 @@

 .\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

 .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 .\"

-.Dd October 7, 2006

-.Dt EVDNS 3

-.Os

-.Sh NAME

-.Nm evdns_init

-.Nm evdns_shutdown

-.Nm evdns_err_to_string

-.Nm evdns_nameserver_add

-.Nm evdns_count_nameservers

-.Nm evdns_clear_nameservers_and_suspend

-.Nm evdns_resume

-.Nm evdns_nameserver_ip_add

-.Nm evdns_resolve_ipv4

-.Nm evdns_resolve_reverse

-.Nm evdns_resolv_conf_parse

-.Nm evdns_config_windows_nameservers

-.Nm evdns_search_clear

-.Nm evdns_search_add

-.Nm evdns_search_ndots_set

-.Nm evdns_set_log_fn

-.Nd asynchronous functions for DNS resolution.

-.Sh SYNOPSIS

-.Fd #include <sys/time.h>

-.Fd #include <event.h>

-.Fd #include <evdns.h>

-.Ft int

-.Fn evdns_init

-.Ft void

-.Fn evdns_shutdown "int fail_requests"

-.Ft "const char *"

-.Fn evdns_err_to_string "int err"

-.Ft int

-.Fn evdns_nameserver_add "unsigned long int address"

-.Ft int

-.Fn evdns_count_nameservers

-.Ft int

-.Fn evdns_clear_nameservers_and_suspend

-.Ft int

-.Fn evdns_resume

-.Ft int

-.Fn evdns_nameserver_ip_add(const char *ip_as_string);

-.Ft int

-.Fn evdns_resolve_ipv4 "const char *name" "int flags" "evdns_callback_type callback" "void *ptr"

-.Ft int

-.Fn evdns_resolve_reverse "struct in_addr *in" "int flags" "evdns_callback_type callback" "void *ptr"

-.Ft int

-.Fn evdns_resolv_conf_parse "int flags" "const char *"

-.Ft void

-.Fn evdns_search_clear

-.Ft void

-.Fn evdns_search_add "const char *domain"

-.Ft void

-.Fn evdns_search_ndots_set "const int ndots"

-.Ft void

-.Fn evdns_set_log_fn "evdns_debug_log_fn_type fn"

-.Ft int

-.Fn evdns_config_windows_nameservers

-.Sh DESCRIPTION

+.TH EVDNS 3 "21 November 2011" "libevent 1.4.14b" "libevent Manual"

+.SH NAME

+evdns_init,

+evdns_shutdown,

+evdns_err_to_string,

+evdns_nameserver_add,

+evdns_count_nameservers,

+evdns_clear_nameservers_and_suspend,

+evdns_resume,

+evdns_nameserver_ip_add,

+evdns_resolve_ipv4,

+evdns_resolve_reverse,

+evdns_resolv_conf_parse,

+evdns_config_windows_nameservers,

+evdns_search_clear,

+evdns_search_add,

+evdns_search_ndots_set,

+evdns_set_log_fn

+\- asynchronous functions for DNS resolution.

+.SH SYNOPSIS

+.LP

+.nf

+\fB#include <sys/time.h>\fP

+\fB#include <event.h>\fP

+\fB#include <evdns.h>\fP

+

+\fBinit \fBevdns_init\fR\fR(\fBvoid\fP\fR);

+

+\fBvoid \fBevdns_shutdown\fR\fR(\fBint \fIfail_requests\fP\fR);

+

+\fBconst char* \fBevdns_err_to_string\fR\fR(\fBint \fIerr\fP\fR);

+

+\fBint \fBevdns_nameserver_add\fR\fR(\fBunsigned long int \fIaddress\fP\fR);

+

+\fBint \fBevdns_count_nameservers\fR\fR(\fBvoid\fP\fR);

+

+\fBint \fBevdns_clear_nameservers_and_suspend\fR\fR(\fBvoid\fP\fR);

+

+\fBint \fBevdns_resume\fR\fR(\fBvoid\fP\fR);

+

+\fBint \fBevdns_nameserver_ip_add\fR\fR(\fBconst char* \fIip_as_string\fP\fR);

+

+\fBint \fBevdns_resolve_ipv4\fR\fR(\fBconst char* \fIname\fP\fR, \fBint \fIflags\fP\fR, \fBevdns_callback_type \fIcallback\fP\fR, \fBvoid* \fIptr\fP\fR);

+

+\fBint \fBevdns_resolve_reverse\fR\fR(\fBstruct in_addr* \fIin\fP\fR, \fBint \fIflags\fP\fR, \fBevdns_callback_type \fIcallback\fP\fR, \fBvoid* \fIptr\fP\fR);

+

+\fBint \fBevdns_resolv_conf_parse\fR\fR(\fBint \fIflags\fP\fR, \fBconst char* \fIfilename\fP\fR);

+

+\fBvoid \fBevdns_search_clear\fR\fR(\fBvoid\fP\fR);

+

+\fBvoid \fBevdns_search_add\fR\fR(\fBconst char* \fIdomain\fP\fR);

+

+\fBvoid \fBevdns_search_ndots_set\fR\fR(\fBconst int \fIndots\fP\fR);

+

+\fBvoid \fBevdns_set_log_fn\fR\fR(\fBcevdns_debug_log_fn_type \fIfn\fP\fR);

+

+\fBint \fBevdns_config_windows_nameservers\fR\fR(\fBvoid\fP\fR);

+.fi

+.SH DESCRIPTION

 Welcome, gentle reader

-.Pp

+.PP

 Async DNS lookups are really a whole lot harder than they should be,

 mostly stemming from the fact that the libc resolver has never been

 very good at them. Before you use this library you should see if libc

@@ -91,37 +92,49 @@

 can do the job for you with the modern async call getaddrinfo_a

 (see http://www.imperialviolet.org/page25.html#e498). Otherwise,

 please continue.

-.Pp

+.PP

 This code is based on libevent and you must call event_init before

 any of the APIs in this file. You must also seed the OpenSSL random

 source if you are using OpenSSL for ids (see below).

-.Pp

+.PP

 This library is designed to be included and shipped with your source

 code. You statically link with it. You should also test for the

 existence of strtok_r and define HAVE_STRTOK_R if you have it.

-.Pp

+.PP

 The DNS protocol requires a good source of id numbers and these

 numbers should be unpredictable for spoofing reasons. There are

 three methods for generating them here and you must define exactly

 one of them. In increasing order of preference:

-.Pp

-.Bl -tag -width "DNS_USE_GETTIMEOFDAY_FOR_ID" -compact -offset indent

-.It DNS_USE_GETTIMEOFDAY_FOR_ID

+.PP

+DNS_USE_GETTIMEOFDAY_FOR_ID

+.ad

+.sp .6

+.RS 4n

 Using the bottom 16 bits of the usec result from gettimeofday. This

 is a pretty poor solution but should work anywhere.

-.It DNS_USE_CPU_CLOCK_FOR_ID

+.RE

+.PP

+DNS_USE_CPU_CLOCK_FOR_ID

+.ad

+.sp .6

+.RS 4n

 Using the bottom 16 bits of the nsec result from the CPU's time

 counter. This is better, but may not work everywhere. Requires

 POSIX realtime support and you'll need to link against -lrt on

 glibc systems at least.

-.It DNS_USE_OPENSSL_FOR_ID

+.RE

+.PP

+DNS_USE_OPENSSL_FOR_ID

+.ad

+.sp .6

+.RS 4n

 Uses the OpenSSL RAND_bytes call to generate the data. You must

 have seeded the pool before making any calls to this library.

-.El

-.Pp

+.RE

+.PP

 The library keeps track of the state of nameservers and will avoid

 them when they go down. Otherwise it will round robin between them.

-.Pp

+.PP

 Quick start guide:

   #include "evdns.h"

   void callback(int result, char type, int count, int ttl,

@@ -128,7 +141,7 @@

 	 void *addresses, void *arg);

   evdns_resolv_conf_parse(DNS_OPTIONS_ALL, "/etc/resolv.conf");

   evdns_resolve("www.hostname.com", 0, callback, NULL);

-.Pp

+.PP

 When the lookup is complete the callback function is called. The

 first argument will be one of the DNS_ERR_* defines in evdns.h.

 Hopefully it will be DNS_ERR_NONE, in which case type will be

@@ -136,152 +149,187 @@

 which the data can be cached for (in seconds), addresses will point

 to an array of uint32_t's and arg will be whatever you passed to

 evdns_resolve.

-.Pp

+.PP

 Searching:

-.Pp

+.PP

 In order for this library to be a good replacement for glibc's resolver it

 supports searching. This involves setting a list of default domains, in

 which names will be queried for. The number of dots in the query name

 determines the order in which this list is used.

-.Pp

+.PP

 Searching appears to be a single lookup from the point of view of the API,

 although many DNS queries may be generated from a single call to

 evdns_resolve. Searching can also drastically slow down the resolution

 of names.

-.Pp

+.PP

 To disable searching:

-.Bl -enum -compact -offset indent

-.It

-Never set it up. If you never call

-.Fn evdns_resolv_conf_parse,

-.Fn evdns_init,

+.ad

+.sp .6

+.RS 4n

+1. Never set it up. If you never call

+\fBevdns_resolv_conf_parse\fP\fR,

+\fBevdns_init\fP\fR,

 or

-.Fn evdns_search_add

+\fBevdns_search_add\fP\R

 then no searching will occur.

-.It

-If you do call

-.Fn evdns_resolv_conf_parse

+.br

+2. If you do call

+\fBevdns_resolv_conf_parse\fP\fR

 then don't pass

-.Va DNS_OPTION_SEARCH

+DNS_OPTION_SEARCH

 (or

-.Va DNS_OPTIONS_ALL,

+DNS_OPTIONS_ALL,

 which implies it).

-.It

-When calling

-.Fn evdns_resolve,

+.br

+3. When calling

+\fBevdns_resolve\fP\fR,

 pass the

-.Va DNS_QUERY_NO_SEARCH

+DNS_QUERY_NO_SEARCH

 flag.

-.El

-.Pp

+.RE

+.PP

 The order of searches depends on the number of dots in the name. If the

 number is greater than the ndots setting then the names is first tried

 globally. Otherwise each search domain is appended in turn.

-.Pp

+.PP

 The ndots setting can either be set from a resolv.conf, or by calling

 evdns_search_ndots_set.

-.Pp

+.PP

 For example, with ndots set to 1 (the default) and a search domain list of

 ["myhome.net"]:

  Query: www

  Order: www.myhome.net, www.

-.Pp

+.PP

  Query: www.abc

  Order: www.abc., www.abc.myhome.net

-.Pp

-.Sh API reference

-.Pp

-.Bl -tag -width 0123456

-.It Ft int Fn evdns_init

+.PP

+.SH API reference

+.PP

+.SS "\fBint \fBevdns_init\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Initializes support for non-blocking name resolution by calling

-.Fn evdns_resolv_conf_parse

+evdns_resolv_conf_parse()

 on UNIX and

-.Fn evdns_config_windows_nameservers

+evdns_config_windows_nameservers()

 on Windows.

-.It Ft int Fn evdns_nameserver_add "unsigned long int address"

+.SS "\fBint \fBevdns_nameserver_add\fR\fR(\fBunsigned long int\fP\fR \fIaddress\fP\fR)"

+.sp

+.LP

 Add a nameserver. The address should be an IP address in

 network byte order. The type of address is chosen so that

 it matches in_addr.s_addr.

 Returns non-zero on error.

-.It Ft int Fn evdns_nameserver_ip_add "const char *ip_as_string"

+.SS "\fBint \fBevdns_nameserver_ip_add\fR\fR(\fBconst char* \fIip_as_string\fP\fR)"

+.sp

+.LP

 This wraps the above function by parsing a string as an IP

 address and adds it as a nameserver.

 Returns non-zero on error

-.It Ft int Fn evdns_resolve "const char *name" "int flags" "evdns_callback_type callback" "void *ptr"

+.SS "\fBint \fBevdns_resolve\fR\fR(\fBconst char* \fIname\fP\fR, \fBint \fIflags\fP\fR, \fBevdns_callback_type \fIcallback\fP\fR, \fBvoid* \fIptr\fP\fR)"

+.sp

+.LP

 Resolve a name. The name parameter should be a DNS name.

 The flags parameter should be 0, or DNS_QUERY_NO_SEARCH

 which disables searching for this query. (see defn of

 searching above).

-.Pp

+.PP

 The callback argument is a function which is called when

 this query completes and ptr is an argument which is passed

 to that callback function.

-.Pp

+.PP

 Returns non-zero on error

-.It Ft void Fn evdns_search_clear

+.SS "\fBvoid \fBevdns_search_clear\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Clears the list of search domains

-.It Ft void Fn evdns_search_add "const char *domain"

+.SS "\fBvoid \fBevdns_search_add\fR\fR(\fBconst char* \fIdomain\fP\fR)"

+.sp

+.LP

 Add a domain to the list of search domains

-.It Ft void Fn evdns_search_ndots_set "int ndots"

+.SS "\fBvoid \fBevdns_search_ndots_set\fR\fR(\fBconst int \fIndots\fP\fR)"

+.sp

+.LP

 Set the number of dots which, when found in a name, causes

 the first query to be without any search domain.

-.It Ft int Fn evdns_count_nameservers "void"

+.SS "\fBint \fBevdns_count_nameservers\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Return the number of configured nameservers (not necessarily the

 number of running nameservers).  This is useful for double-checking

 whether our calls to the various nameserver configuration functions

 have been successful.

-.It Ft int Fn evdns_clear_nameservers_and_suspend "void"

+.SS "\fBint \fBevdns_clear_nameservers_and_suspend\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Remove all currently configured nameservers, and suspend all pending

 resolves.  Resolves will not necessarily be re-attempted until

 evdns_resume() is called.

-.It Ft int Fn evdns_resume "void"

+.SS "\fBint \fBevdns_resume\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Re-attempt resolves left in limbo after an earlier call to

 evdns_clear_nameservers_and_suspend().

-.It Ft int Fn evdns_config_windows_nameservers "void"

+.SS "\fBint \fBevdns_config_windows_nameservers\fR\fR(\fBvoid\fP\fR)"

+.sp

+.LP

 Attempt to configure a set of nameservers based on platform settings on

 a win32 host.  Preferentially tries to use GetNetworkParams; if that fails,

 looks in the registry.  Returns 0 on success, nonzero on failure.

-.It Ft int Fn evdns_resolv_conf_parse "int flags" "const char *filename"

+.SS "\fBint \fBevdns_resolv_conf_parse\fR\fR(\fBint \fIflags\fP\fR, \fBconst char*filename\fP\fR)"

+.sp

+.LP

 Parse a resolv.conf like file from the given filename.

-.Pp

+.PP

 See the man page for resolv.conf for the format of this file.

 The flags argument determines what information is parsed from

 this file:

-.Bl -tag -width "DNS_OPTION_NAMESERVERS" -offset indent -compact -nested

-.It DNS_OPTION_SEARCH

+.sp

+DNS_OPTION_SEARCH

 domain, search and ndots options

-.It DNS_OPTION_NAMESERVERS

+.br

+DNS_OPTION_NAMESERVERS

 nameserver lines

-.It DNS_OPTION_MISC

+.br

+DNS_OPTION_MISC

 timeout and attempts options

-.It DNS_OPTIONS_ALL

+.br

+DNS_OPTIONS_ALL

 all of the above

-.El

-.Pp

+.PP

 The following directives are not parsed from the file:

   sortlist, rotate, no-check-names, inet6, debug

-.Pp

+.PP

 Returns non-zero on error:

-.Bl -tag -width "0" -offset indent -compact -nested

-.It 0

+.sp

+0

+.br

 no errors

-.It 1

+.br

+1

+.br

 failed to open file

-.It 2

+.br

+2

+.br

 failed to stat file

-.It 3

+.br

+3

+.br

 file too large

-.It 4

+.br

+4

+.br

 out of memory

-.It 5

+.br

+5

+.br

 short read from file

-.El

-.El

-.Sh Internals:

+.SH Internals:

 Requests are kept in two queues. The first is the inflight queue. In

 this queue requests have an allocated transaction id and nameserver.

 They will soon be transmitted if they haven't already been.

-.Pp

+.PP

 The second is the waiting queue. The size of the inflight ring is

 limited and all other requests wait in waiting queue for space. This

 bounds the number of concurrent requests so that we don't flood the

@@ -288,33 +336,33 @@

 nameserver. Several algorithms require a full walk of the inflight

 queue and so bounding its size keeps thing going nicely under huge

 (many thousands of requests) loads.

-.Pp

+.PP

 If a nameserver loses too many requests it is considered down and we

 try not to use it. After a while we send a probe to that nameserver

 (a lookup for google.com) and, if it replies, we consider it working

 again. If the nameserver fails a probe we wait longer to try again

 with the next probe.

-.Sh SEE ALSO

-.Xr event 3 ,

-.Xr gethostbyname 3 ,

-.Xr resolv.conf 5

-.Sh HISTORY

+.SH SEE ALSO

+\fBevent(3)\fR,

+\fBgethostbyname(3)\fR,

+\fBresolv.conf(4)\fR

+.SH HISTORY

 The

-.Nm evdns

+\fIevdns\fP\fR

 API was developed by Adam Langley on top of the

-.Nm libevent

+\fIlibevent\fP\fR

 API.

 The code was integrate into

-.Nm Tor

+\fITor\fP\fR

 by Nick Mathewson and finally put into

-.Nm libevent

+\fIlibevent\fP\fR

 itself by Niels Provos.

-.Sh AUTHORS

+.SH AUTHORS

 The

-.Nm evdns

+\fIevdns\fP\fR

 API and code was written by Adam Langley with significant

 contributions by Nick Mathewson.

-.Sh BUGS

+.SH BUGS

 This documentation is neither complete nor authoritative.

 If you are in doubt about the usage of this API then

 check the source code to find out how it works, write