path: root/secure/lib/libcrypto/man/man3/BIO_should_retry.3
diff options
authorJung-uk Kim <jkim@FreeBSD.org>2020-02-21 00:33:21 +0000
committerJung-uk Kim <jkim@FreeBSD.org>2020-02-21 00:33:21 +0000
commit6b4382c4054d7c169c6140feaa144ca360a90ead (patch)
tree176bf7fdbae226099058e11e9a429805b6e0af42 /secure/lib/libcrypto/man/man3/BIO_should_retry.3
parent24722aacdb06a5ac6780beef7db856a0f99095c3 (diff)
MFC: r356963
Install man5 and man7 for OpenSSL.
Notes: svn path=/stable/12/; revision=358188
Diffstat (limited to 'secure/lib/libcrypto/man/man3/BIO_should_retry.3')
1 files changed, 273 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/man3/BIO_should_retry.3 b/secure/lib/libcrypto/man/man3/BIO_should_retry.3
new file mode 100644
index 000000000000..c2e0991d6d87
--- /dev/null
+++ b/secure/lib/libcrypto/man/man3/BIO_should_retry.3
@@ -0,0 +1,273 @@
+.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.39)
+.\" Standard preamble:
+.\" ========================================================================
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+.de Vb \" Begin verbatim text
+.ft CW
+.ne \\$1
+.de Ve \" End verbatim text
+.ft R
+.\" Set up some character translations and predefined strings. \*(-- will
+.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
+.\" double quote, and \*(R" will give a right double quote. \*(C+ will
+.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
+.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
+.\" nothing in troff, for use with C<>.
+.tr \(*W-
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+. ds -- \(*W-
+. ds PI pi
+. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
+. ds L" ""
+. ds R" ""
+. ds C` ""
+. ds C' ""
+. ds -- \|\(em\|
+. ds PI \(*p
+. ds L" ``
+. ds R" ''
+. ds C`
+. ds C'
+.\" Escape single quotes in literal strings from groff's Unicode transform.
+.ie \n(.g .ds Aq \(aq
+.el .ds Aq '
+.\" If the F register is >0, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
+.\" entries marked with X<> in POD. Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.\" Avoid warning from groff about undefined register 'F'.
+.de IX
+.nr rF 0
+.if \n(.g .if rF .nr rF 1
+.if (\n(rF:(\n(.g==0)) \{\
+. if \nF \{\
+. de IX
+. tm Index:\\$1\t\\n%\t"\\$2"
+. if !\nF==2 \{\
+. nr % 0
+. nr F 2
+. \}
+. \}
+.rr rF
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear. Run. Save yourself. No user-serviceable parts.
+. \" fudge factors for nroff and troff
+.if n \{\
+. ds #H 0
+. ds #V .8m
+. ds #F .3m
+. ds #[ \f1
+. ds #] \fP
+.if t \{\
+. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+. ds #V .6m
+. ds #F 0
+. ds #[ \&
+. ds #] \&
+. \" simple accents for nroff and troff
+.if n \{\
+. ds ' \&
+. ds ` \&
+. ds ^ \&
+. ds , \&
+. ds ~ ~
+. ds /
+.if t \{\
+. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+. \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+. \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+. \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+. ds : e
+. ds 8 ss
+. ds o a
+. ds d- d\h'-1'\(ga
+. ds D- D\h'-1'\(hy
+. ds th \o'bp'
+. ds Th \o'LP'
+. ds ae ae
+. ds Ae AE
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.TH BIO_SHOULD_RETRY 3 "2019-09-10" "1.1.1d" "OpenSSL"
+.\" For nroff, turn off justification. Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.if n .ad l
+BIO_should_read, BIO_should_write, BIO_should_io_special, BIO_retry_type, BIO_should_retry, BIO_get_retry_BIO, BIO_get_retry_reason, BIO_set_retry_reason \- BIO retry functions
+.IX Header "SYNOPSIS"
+.Vb 1
+\& #include <openssl/bio.h>
+\& int BIO_should_read(BIO *b);
+\& int BIO_should_write(BIO *b);
+\& int BIO_should_io_special(iBIO *b);
+\& int BIO_retry_type(BIO *b);
+\& int BIO_should_retry(BIO *b);
+\& BIO *BIO_get_retry_BIO(BIO *bio, int *reason);
+\& int BIO_get_retry_reason(BIO *bio);
+\& void BIO_set_retry_reason(BIO *bio, int reason);
+These functions determine why a \s-1BIO\s0 is not able to read or write data.
+They will typically be called after a failed \fBBIO_read_ex()\fR or \fBBIO_write_ex()\fR
+\&\fBBIO_should_retry()\fR is true if the call that produced this condition
+should then be retried at a later time.
+If \fBBIO_should_retry()\fR is false then the cause is an error condition.
+\&\fBBIO_should_read()\fR is true if the cause of the condition is that the \s-1BIO\s0
+has insufficient data to return. Check for readability and/or retry the
+last operation.
+\&\fBBIO_should_write()\fR is true if the cause of the condition is that the \s-1BIO\s0
+has pending data to write. Check for writability and/or retry the
+last operation.
+\&\fBBIO_should_io_special()\fR is true if some \*(L"special\*(R" condition, that is a
+reason other than reading or writing is the cause of the condition.
+\&\fBBIO_retry_type()\fR returns a mask of the cause of a retry condition
+consisting of the values \fB\s-1BIO_FLAGS_READ\s0\fR, \fB\s-1BIO_FLAGS_WRITE\s0\fR,
+\&\fB\s-1BIO_FLAGS_IO_SPECIAL\s0\fR though current \s-1BIO\s0 types will only set one of
+\&\fBBIO_get_retry_BIO()\fR determines the precise reason for the special
+condition, it returns the \s-1BIO\s0 that caused this condition and if
+\&\fBreason\fR is not \s-1NULL\s0 it contains the reason code. The meaning of
+the reason code and the action that should be taken depends on
+the type of \s-1BIO\s0 that resulted in this condition.
+\&\fBBIO_get_retry_reason()\fR returns the reason for a special condition if
+passed the relevant \s-1BIO,\s0 for example as returned by \fBBIO_get_retry_BIO()\fR.
+\&\fBBIO_set_retry_reason()\fR sets the retry reason for a special condition for a given
+\&\s-1BIO.\s0 This would usually only be called by \s-1BIO\s0 implementations.
+.IX Header "NOTES"
+\&\fBBIO_should_read()\fR, \fBBIO_should_write()\fR, \fBBIO_should_io_special()\fR,
+\&\fBBIO_retry_type()\fR, and \fBBIO_should_retry()\fR, are implemented as macros.
+If \fBBIO_should_retry()\fR returns false then the precise \*(L"error condition\*(R"
+depends on the \s-1BIO\s0 type that caused it and the return code of the \s-1BIO\s0
+operation. For example if a call to \fBBIO_read_ex()\fR on a socket \s-1BIO\s0 returns
+0 and \fBBIO_should_retry()\fR is false then the cause will be that the
+connection closed. A similar condition on a file \s-1BIO\s0 will mean that it
+has reached \s-1EOF.\s0 Some \s-1BIO\s0 types may place additional information on
+the error queue. For more details see the individual \s-1BIO\s0 type manual
+If the underlying I/O structure is in a blocking mode almost all current
+\&\s-1BIO\s0 types will not request a retry, because the underlying I/O
+calls will not. If the application knows that the \s-1BIO\s0 type will never
+signal a retry then it need not call \fBBIO_should_retry()\fR after a failed
+\&\s-1BIO I/O\s0 call. This is typically done with file BIOs.
+\&\s-1SSL\s0 BIOs are the only current exception to this rule: they can request a
+retry even if the underlying I/O structure is blocking, if a handshake
+occurs during a call to \fBBIO_read()\fR. An application can retry the failed
+call immediately or avoid this situation by setting \s-1SSL_MODE_AUTO_RETRY\s0
+on the underlying \s-1SSL\s0 structure.
+While an application may retry a failed non blocking call immediately
+this is likely to be very inefficient because the call will fail
+repeatedly until data can be processed or is available. An application
+will normally wait until the necessary condition is satisfied. How
+this is done depends on the underlying I/O structure.
+For example if the cause is ultimately a socket and \fBBIO_should_read()\fR
+is true then a call to \fBselect()\fR may be made to wait until data is
+available and then retry the \s-1BIO\s0 operation. By combining the retry
+conditions of several non blocking BIOs in a single \fBselect()\fR call
+it is possible to service several BIOs in a single thread, though
+the performance may be poor if \s-1SSL\s0 BIOs are present because long delays
+can occur during the initial handshake process.
+It is possible for a \s-1BIO\s0 to block indefinitely if the underlying I/O
+structure cannot process or return any data. This depends on the behaviour of
+the platforms I/O functions. This is often not desirable: one solution
+is to use non blocking I/O and use a timeout on the \fBselect()\fR (or
+equivalent) call.
+.IX Header "BUGS"
+The OpenSSL \s-1ASN1\s0 functions cannot gracefully deal with non blocking I/O:
+that is they cannot retry after a partial read or write. This is usually
+worked around by only passing the relevant data to \s-1ASN1\s0 functions when
+the entire structure can be read or written.
+\&\fBBIO_should_read()\fR, \fBBIO_should_write()\fR, \fBBIO_should_io_special()\fR, and
+\&\fBBIO_should_retry()\fR return either 1 or 0 based on the actual conditions
+of the \fB\s-1BIO\s0\fR.
+\&\fBBIO_retry_type()\fR returns a flag combination presenting the cause of a retry
+condition or false if there is no retry condition.
+\&\fBBIO_get_retry_BIO()\fR returns a valid \fB\s-1BIO\s0\fR structure.
+\&\fBBIO_get_retry_reason()\fR returns the reason for a special condition.
+.IX Header "SEE ALSO"
+.IX Header "HISTORY"
+The \fBBIO_get_retry_reason()\fR and \fBBIO_set_retry_reason()\fR functions were added in
+OpenSSL 1.1.0.
+Copyright 2000\-2018 The OpenSSL Project Authors. All Rights Reserved.
+Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use
+this file except in compliance with the License. You can obtain a copy
+in the file \s-1LICENSE\s0 in the source distribution or at