changes

linux下qmail的源码 本人加了一些注释

19960605 change: added qqtalk_qp.
19960605 change: qmail-send now logs uid and qp from todo file. 14 lines
         extra code.
19960605 change: qmail-queue now records uid and qp in u and p lines
         in todo file. 7 lines extra code.
19960605 change: improved qmail-alias x-bit error messages.
19960605 change: newline in log is now converted to /, not underscore.
19960604 change: when it accepts a message, qmail-smtpd includes the
         local time in its 250 response.
19960604 change: on success, qmail-alias prints delivery counts,
         file+forward+program.
19960603 change: qmail-remote now reports IP address on success. tnx MD.
19960603 change: qmail-send now logs success and failure reports, not
         just deferral reports.
19960603 change: added netbsd section in find-systype, same as bsd.os
         section. this will affect netbsd-* systypes. tnx MBS.
19960530 qmail 0.75, beta.
19960528 change: added qmail.7. tnx MD.
19960525 change: added qmail-pop3d. tnx RN.
19960525 change: added qmail-popup. tnx RN.
19960525 change: added elm filter section to FAQ. tnx GB.
19960502 portability problem: on many systems, select() on an
         almost-full pipe incorrectly says writable. tnx ME for running
	 into this and helping track it down. impact: if qmail-send
	 writes a pipeful to qmail-lspawn or qmail-rspawn before they
	 can react (because of high concurrency, high load, or long
	 addresses), it will receive an incorrect -1/EAGAIN, and will
	 conclude that spawn died. sysadmin will have to restart qmail,
	 and messages will be duplicated. fix: in qmail-send.c,
	 busy-loop if write() to spawn returns any error other than
	 EPIPE.
19960501 bug: qmail-alias treated NAMETOOLONG and NOTDIR as temporary
         errors. impact: qmail-alias never looked for -default; even if
	 mail was destined to bounce, it would have to time out first.
	 fix: qmail-alias now uses error_temp().
19960430 bug: qmail-smtpd treated qq crash as permanent error. impact:
         if somebody actively kills qq, mail will be incorrectly
	 bounced. tnx SS. fix: qmail-smtpd now treats only TOOLONG and
	 EXECHARD as permanent errors.
19960430 cleanup: eliminated QQT_TTY from qqtalk.h.
19960428 change: added ``warning: '' before trouble-marking message.
19960428 change: added percenthack. requested by GB.
19960428 cleanup: switched to auto-generated Makefile.
19960428 cleanup: switched to auto-generated .o dependencies.
19960428 cleanup: eliminated fmt.o, scan.o from Makefile.
19960428 portability problem: under HP-UX 10, the rc pgrp is sent HUP
         when rc finishes. tnx BG. impact: the qmail daemons are killed
	 when rc finishes. fix: added special note in INSTALL (sigh) to
	 use csh -cf.
19960427 cleanup: added PORT_SMTP in qmail-remote.c.
19960427 cleanup: introduced timeoutwrite.c. used it in qmail-remote.c.
19960427 cleanup: introduced timeoutread.c. used it in qmail-remote.c.
19960427 cleanup: introduced timeoutconn.c. used it in qmail-remote.c.
19960427 change: added timeoutconnect. default: 60 seconds.
19960427 change: added pop3d instructions to FAQ. tnx RN.
19960427 change: eliminated env manipulation from qmail-start. tnx BG.
19960427 change: headerbody now ends header, inserting blank line, if
         first line of a header field doesn't pass hfield_valid. tnx TG.
19960427 change: headerbody now prepends MBOX-Line: to any header line
         starting From_. this lets qmail-inject work with elm's bounce.
	 tnx OR, K1J, et al.
19960426 change: added moreinfo arg to qlist and qlist2.
19960426 change: added signal_uncatchchild() to qmail-send.c. tnx BG.
         now, if sysadmin sets SIGCHLD to SIG_IGN before invoking
	 qmail-send [sigh], qmail-send won't screw up bounce messages.
19960426 change: dns_cname now checks whether last character is ],
         rather than whether first character is [, for quick return.
19960426 cleanup: glue is now global in dns.c.
19960426 cleanup: qmail-remote no longer does stralloc_0 for host and
         canonhost.
19960426 change: dns_mxip no longer rejects [foo].bar.
19960426 change: dns_mxip no longer requires for bracket that input
         be 0-terminated.
19960426 change: qmail-start can now take logger as an argument.
19960426 change: qmail-start now invokes qmail-send in foreground (as
         parent of other processes).
19960426 change: added mailsubj. tnx GAW.
19960426 portability problem: under some systems, can't lock read-only
         file. impact: maildir2mbox would always fail on those systems.
	 fix: maildir2mbox now opens a separate lock fd. tnx BG.
19960426 cleanup: removed unnecessary #!/bin/sh and # AUTO from mctl.sh.
19960426 change: added qmail-qstat.
19960426 change: added qmail-qread.8.
19960426 change: renamed qmail-mailq as qmail-qread.
19960419 change: qmail-alias now defers delivery rather than skipping
         blank lines in .qmail.
19960419 change: in qmail-lspawn.c, lowercased name before getpwnam().
         really getpwnam() should do this, but oh well.
19960419 change: added username to qmail-lspawn.c, with LSPAWN_USERLEN
         in conf-unusual.h. names longer than LSPAWN_USERLEN will skip
	 getpwnam().
19960419 change: if qlist doesn't see any cmds, it presumes that you
         meant to subscribe.
19960419 change: reorganized qlist acknowledgment format.
19960415 change: reorganized and rewrote FAQ.
19960415 change: renamed HOWTO as FAQ.
19960414 change: in qmail-alias, converted extension to lowercase just
         before qmeopen(), qmeox() calls. thus EXTENSION and USEREXT and
	 RECIPIENT will preserve case passed by qmail-lspawn, while
	 .qmailext lookups will not.
19960414 change: removed case_lowers(r) from qmail-lspawn.c. tnx JLH.
19960414 change: moved extension . -> : conversion to just before
         qmeopen(), qmeox() calls in qmail-alias.c. thus EXTENSION and
	 USEREXT and RECIPIENT will preserve dots.
19960414 change: qsmhook -x now does case-independent comparison.
19960413 change: added procmail instructions to HOWTO.
19960409 bug: qmail-alias does not check for newlines when it generates
         Return-Path. impact: resulting Return-Path header field will be
	 illegal, if sender address contains newline followed by
	 something other than whitespace. fix: qmail-alias now replaces
	 newline with underscore in rpline.
19960409 change: added leaf UUCP description to HOWTO. tnx J2K.
19960409 change: added -B option to sendmail. tnx OR.
19960409 change: qlist now makes lists unwritable (after renaming from
         .qtemp to .qmail). tnx MLH.
19960409 change: added flagdtline to qsmhook.c, based on -l option.
19960409 change: added PIPELINING declaration to qmail-smtpd. tnx JGM.
19960409 change: qmail-smtpd now flushes output instantly after DATA,
         QUIT, HELO, EHLO, NOOP, VRFY, or any 502.
19960409 change: qmail-smtpd now flushes output upon read() and death.
19960409 change: qmail-smtpd no longer flushes output in out().
19960409 change: increased qmail-smtpd outbuf size from 128 to 512.
19960409 cleanup: in qmail-smtpd, eliminated ssinit() in favor of FDBUF.
19960409 bug: qmail-alias produced aliasfoo-owner rather than foo-owner
         as envelope sender for ~alias/.qmailfoo. tnx DS. impact: wrong
	 envelope sender whenever ~alias/.qmailfoo-owner existed. fix:
	 qmail-alias now checks for hyphen at beginning of extension.
19960409 change: added _ESMTP to end of 220. tnx JLH.
19960409 change: moved out("\r\n") out of smtp_greet() into callers.
         this improves the flushing behavior on 221.
19960328 qmail 0.74, beta.
19960326 change: changed subdirectory split from 32 to 23.
19960326 portability problem: some versions of make don't understand
         that a line with just a tab is blank. impact: couldn't compile
	 under those systems. fix: eliminated extra tab from Makefile.
	 tnx TG.
19960325 change: added qmail-mailq.
19960325 change: introduced readsubdir.
19960325 change: qmail-setup makes split; qmail-check checks split.
19960325 change: used split in qmail-send, qmail-clean, qmail-queue
         for mess, info, local, remote.
19960325 change: fmtqfn now supports split queue subdirectories.
19960325 cleanup: eliminated cat2s().
19960325 cleanup: introduced fmtqfn.c. used it in qmail-queue.c,
         qmail-send.c, qmail-clean.c.
19960325 change: in protocol between qmail-clean and qmail-send, now
         using intd/ instead of mess/.
19960325 change: qmail-queue.c and triggerpull.c now work inside queue
         subdirectory.
19960325 change: spawn.c now checks whether message is a regular file.
19960325 change: spawn.c now allows slashes in messid except at
         beginning.
19960325 cleanup: introduced fnmake_split in qmail-send.c.
19960325 cleanup: eliminated strnum in qmail-send.c in favor of
         fnmake_{info,todo,mess,chanaddr} and fnmake2_bounce.
19960325 cleanup: introduced strnum3 in qmail-send.c for the logging
         uses of strnum.
19960325 cleanup: in qmail-send.c, getinfo() now takes id argument.
19960325 cleanup: qmail-send.c now preallocates space for fn, fn2.
19960325 change: time zone is now -0000 instead of +0000. encouraging
         DRUMS to use this as an i-don't-know-the-local-time indicator.
19960324 change: qmail-rspawn.c now calls tcpto_clean().
19960324 cleanup: spawn.c now calls initialize().
19960324 change: qmail-setup makes lock/tcpto; qmail-check checks it.
19960324 change: qmail-remote now quickly skips connect() to a host that
         seems to be down. tnx BP for pressuring me to get this done.
19960323 change: in qmail-alias.8, renamed mboxg as mboxrd. tnx RD.
         idea was popularized by RD in June 1995.
19960322 cleanup: eliminated subfd_init().
19960322 change: qbiff now removes the word Subject.
19960322 change: now /bin/true instead of /dev/null in the generic
         INSTALL.ids instructions. tnx JPR.
19960322 change: added hfield_skipname(). tnx RN.
19960322 bug: qmail-inject did not check whether USER needed quoting.
         impact: if USER had weird characters, the From address would
	 generally be wrong, unless the user manually set up MAILUSER
	 with proper quoting. fix: qmail-inject sets up a quoted-string
	 if necessary.
19960322 cleanup: separated out quote_need() in quote.c.
19960322 cleanup: added stralloc_catb.c. used it in qmail-alias.c,
         qmail-send.c.
19960322 change: qmail-send now uses a quadratic retry schedule from
         birth of each message. this also eliminates clustering.
19960322 cleanup: separated out nextretry() in qmail-send.c.
19960322 change: qmail-remote now passes all non-@ addresses through
         without comment, not just <> and <#>.
19960322 change: replaced # test with anything@[] test in qmail-inject.
19960322 change: replaced # with #@[] in qlist.c, qmail-alias.c,
         qmail-send.c, qreceipt.c.
19960322 change: qmail-lspawn no longer discards messages to <#>.
19960322 cleanup: in qlist, used str_diff for <> and <#> tests.
19960322 change: qmail-alias is now back to testing envelope sender for
         <> and <#>, rather than things without an @.
19960321 change: added 8BITMIME support to qmail-smtpd.
19960321 change: added ESMTP support to qmail-smtpd.
19960318 change: used NEWSENDER in place of SENDER for |forward.
19960318 change: added NEWSENDER.
19960318 change: added HCMSSC support to qmail-alias.c.
19960318 change: added HCMSSC support to spawn.c.
19960318 change: added HCMSSC support to qmail-remote.c.
19960318 change: added HCMSSC support to qmail-smtpd.c.
19960317 portability problem: SCO requires -lsocket -lnsl. impact:
         couldn't compile under SCO. fix: added SCO section in
	 make-cmds.sh. tnx JPR. note that this is for OSR 5; 3.2v4.2
	 will need more fixes, and old 3.2 is basically hopeless.
19960317 bug: newfield_datemake would leave newfield_date alone if it
         was already initialized, even though qmail-send calls
	 newfield_datemake anew for each bounce. impact: bounce messages
	 would usually have an incorrect Date field. fix: redid
	 newfield_datemake to update newfield_date each time.
19960317 change: allowed . and @ in 822 phrases; 822 doesn't allow them,
         but they do show up. tnx to the DRUMS group.
19960317 change: replaced GMT with +0000 in date822fmt.c. this confuses
         a few versions of getdate(), but the DRUMS group is going to
	 outlaw GMT, not just recommend against it as in 1123.
19960317 change: redefined ALIAS_EMPTY to take advantage of . for file
         deliveries. tnx RN.
19960317 change: qmail-alias now allows . as well as / to start file
         deliveries. tnx RN.
19960317 change: qmail-alias now dies (soft) if .qmail is writable to
         others, rather than silently ignoring it.
19960317 change: qmail-alias now dies (soft) if flagforwardonly is
         violated, rather than silently ignoring the bad instructions.
19960317 change: qmail-alias now ignores x bit on empty .qmail files.
19960317 bug: if RCPT gave 4xx and DATA gave 5xx, qmail-rspawn would
         incorrectly assign a permanent failure to that recipient.
	 impact: in that case, mail would be incorrectly bounced. fix:
	 remove orr > 0 test from qmail-rspawn.c.
19960310 change: tcp-env now uses signal_uninit(). [sigh]
19960310 change: tcp-env now specifically unsets HOST and INFO if they
         are not applicable. just trying to make it more widely usable.
19960310 cleanup: used byte_* in remoteinfo.c, ipme.c, tcp-env.c.
19960310 cleanup: added readwrite.h, eli