usenix.ps

早期freebsd实现

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/F0 10/Times-Bold@0 SF(Mail Systems and Addr)72 60 Q(essing in 4.2bsd)-.18 E(7)
499 60 Q/F1 10/Times-Roman@0 SF .311(Hosts outside of Bell T)87 96 R .311
(elephone Laboratories w)-.7 F .311(ould then only need to kno)-.1 F 2.811(wh)
-.25 G .811 -.25(ow t)402.982 96 T 2.811(og).25 G .312(et to a designated)
433.354 96 R(BTL relay)87 108 Q 2.5(,a)-.65 G(nd the BTL topology w)137.17 108
Q(ould only be maintained inside Bell.)-.1 E .543(There are three major proble\
ms associated with turning UUCP addresses into something reason-)112 124.2 R
.465(able: de\214ning the namespace, creating and propag)87 136.2 R .465
(ating the necessary softw)-.05 F .466(are, and b)-.1 F .466(uilding and main-)
-.2 F(taining the database.)87 148.2 Q F0 2.5(4.1. De\214ning)87 172.2 R
(the Namespace)2.5 E F1 1.015(Putting all UUCP hosts into a \215at namespace \
\(e.g., \[e-mail]\232\) is not practical for a)127 188.4 R .222
(number of reasons.)102 200.4 R .222(First, with o)5.222 F -.15(ve)-.15 G 2.722
(r1).15 G .222(600 sites already)253.292 200.4 R 2.722(,a)-.65 G .222
(nd \(with the increasing a)329.958 200.4 R -.25(va)-.2 G .222
(ilability of ine).25 F(x-)-.15 E(pensi)102 212.4 Q 1.973 -.15(ve m)-.25 H
1.673(icrocomputers and autodialers\) se).15 F -.15(ve)-.25 G 1.672
(ral thousand more coming within a fe).15 F 4.172(wy)-.25 G 1.672(ears, the)
469.008 212.4 R .078
(database update problem is simply intractable if the namespace is \215at.)102
224.4 R .078(Second, there are almost cer)5.078 F(-)-.2 E 2.446
(tainly name con\215icts today)102 236.4 R 7.446(.T)-.65 G 2.446
(hird, as the number of sites gro)232.794 236.4 R 4.946(wt)-.25 G 2.446
(he names become e)386.316 236.4 R -.15(ve)-.25 G 4.946(rl).15 G(ess)491.78
236.4 Q(mnemonic.)102 248.4 Q .534(It seems ine)127 264.6 R .535
(vitable that there be some sort of naming authority for the set of top le)-.25
F -.15(ve)-.25 G 3.035(ln).15 G(ames)483.45 264.6 Q .157
(in the UUCP domain, as unpleasant a possibility as that may seem.)102 276.6 R
.157(It will simply not be possible to)5.157 F(ha)102 288.6 Q .536 -.15(ve o)
-.2 H .236(ne host resolving all names.).15 F .236(It may ho)5.236 F(we)-.25 E
-.15(ve)-.25 G 2.736(rb).15 G 2.736(ep)316.144 288.6 S .236
(ossible to handle this in a f)328.32 288.6 R .237(ashion similar to)-.1 F
1.582(that of assigning names of ne)102 300.6 R 1.582(wsgroups in USENET)-.25 F
6.582(.H)-.74 G -.25(ow)334.758 300.6 S -2.15 -.25(ev e).25 H 2.382 -.4(r, i)
.25 H 4.082(tw).4 G 1.582(ill be essential to encourage)386.582 300.6 R -2.15
-.25(ev e)102 312.6 T .52(ryone to become subdomains of an e).25 F .52
(xisting domain whene)-.15 F -.15(ve)-.25 G 3.02(rp).15 G .52(ossible \212 e)
374.85 312.6 R -.15(ve)-.25 G 3.02(nt).15 G .52(hough this will)442.95 312.6 R
.077(certainly bruise some e)102 324.6 R 2.577(gos. F)-.15 F .077(or e)-.15 F
.077(xample, if a ne)-.15 F 2.577(wh)-.25 G .076
(ost named \231blid\232 were to be added to the UUCP)310.843 324.6 R(netw)102
336.6 Q .65(ork, it w)-.1 F .651(ould probably actually be addressed as \231d.\
bli.UUCP\232 \(i.e., as host \231d\232 in the pseudo-)-.1 F
(domain \231bli\232 rather than as host \231blid\232 in the UUCP domain\).)102
348.6 Q F0 2.5(4.2. Cr)87 372.6 R(eating and Pr)-.18 E(opagating the Softwar)
-.18 E(e)-.18 E F1 .078(The softw)127 388.8 R .078
(are required to implement a consistent namespace is relati)-.1 F -.15(ve)-.25
G .077(ly tri).15 F 2.577(vial. T)-.25 F .277 -.1(wo m)-.8 H(odules).1 E
(are needed, one to handle incoming mail and one to handle outgoing mail.)102
400.8 Q 1.136(The incoming module must be prepared to handle either old or ne)
127 417 R 3.636(ws)-.25 G 1.136(tyle addresses.)416.448 417 R(Ne)6.136 E(w-)
-.25 E .025(style addresses can be passed through unchanged.)102 429 R .024
(Old style addresses must be turned into ne)5.025 F 2.524(ws)-.25 G(tyle)489
429 Q(addresses where possible.)102 441 Q 2.247
(The outgoing module is slightly trickier)127 457.2 R 7.247(.I)-.55 G 4.747(tm)
309.932 457.2 S 2.247(ust do a database lookup on the recipient)325.239 457.2 R
.823(addresses \(passed on the command line\) to determine what hosts to send \
the message to.)102 469.2 R .823(If those)5.823 F .023(hosts do not accept ne)
102 481.2 R .024(w-style addresses, it must transform all addresses in the hea\
der of the message)-.25 F(into old style using the database lookup.)102 493.2 Q
1.197(Both of these modules are straightforw)127 509.4 R 1.197(ard e)-.1 F
1.197(xcept for the issue of modifying the header)-.15 F 6.197(.I)-.55 G(t)
501.22 509.4 Q .944
(seems prudent to choose one format for the message headers.)102 521.4 R -.15
(Fo)5.944 G 3.444(ran).15 G .944(umber of reasons, Berk)391.448 521.4 R(ele)-.1
E(y)-.15 E .824(has elected to use the ARP)102 533.4 R .824
(ANET protocols for message formats.)-.92 F(Ho)5.823 E(we)-.25 E -.15(ve)-.25 G
1.623 -.4(r, t).15 H .823(his protocol is some-).4 F(what dif)102 545.4 Q
(\214cult to parse.)-.25 E(Propag)127 561.6 Q 1.903(ation is some)-.05 F 1.903
(what more dif)-.25 F 4.403(\214cult. There)-.25 F 1.903(are a lar)4.403 F
1.903(ge number of hosts connected to)-.18 F .812(UUCP that will w)102 573.6 R
.811(ant to run completely standard systems \(for v)-.1 F .811
(ery good reasons\).)-.15 F .811(The strate)5.811 F .811(gy is)-.15 F
(not to con)102 585.6 Q -.15(ve)-.4 G(rt the entire netw).15 E
(ork \212 only enough of it it alle)-.1 E(viate the problem.)-.25 E F0 2.5
(4.3. Building)87 609.6 R(and Maintaining the Database)2.5 E F1 .127
(This is by f)127 625.8 R .127(ar the most dif)-.1 F .128(\214cult problem.)
-.25 F 2.628(Ap)5.128 G .128(rototype for this database already e)309.736 625.8
R .128(xists, b)-.15 F .128(ut it is)-.2 F
(maintained by hand and does not pretend to be complete.)102 637.8 Q .701(This\
 problem will be reduced considerably if people choose to group their hosts in\
to subdo-)127 654 R 3.219(mains. This)102 666 R -.1(wo)3.219 G .719
(uld require a global update only when a ne).1 F 3.22(wt)-.25 G .72(op le)
356.47 666 R -.15(ve)-.25 G 3.22(ld).15 G .72(omain joined the netw)396.95 666
R(ork.)-.1 E 2.805(Am)102 678 S .305
(essage to a host in a subdomain could simply be routed to a kno)119.805 678 R
.304(wn domain g)-.25 F(ate)-.05 E -.1(wa)-.25 G 2.804(yf).1 G .304(or further)
465.656 678 R 3.073(processing. F)102 690 R .573(or e)-.15 F .573(xample, the \
address \[e-mail]\232 might be routed to the \231bli\232 g)-.15 F
(ate)-.05 E -.1(wa)-.25 G 3.074(yf).1 G(or)495.67 690 Q(redistrib)102 702 Q
1.376(ution; ne)-.2 F 3.876(wh)-.25 G 1.375
(osts could be added within BLI without notifying the rest of the w)187.632 702
R 3.875(orld. Of)-.1 F(course, other hosts)102 714 Q/F2 10/Times-Italic@0 SF
(could)2.5 E F1(be noti\214ed as an ef)2.5 E(\214cienc)-.25 E 2.5(ym)-.15 G
(easure.)321.01 714 Q F0 -1(Ve)72 756 S(rsion 8.2)1 E(USENIX \255 J)249.805 756
Q(an 83)-.15 E(Last Mod 11/27/93)424.55 756 Q EP
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/F0 10/Times-Bold@0 SF(Mail Systems and Addr)72 60 Q(essing in 4.2bsd)-.18 E(8)
499 60 Q/F1 10/Times-Roman@0 SF .966(There may be more than one domain g)127 96
R(ate)-.05 E -.1(wa)-.25 G 4.767 -.65(y. A).1 H .967
(domain such as BTL, for instance, might)4.117 F(ha)102 108 Q .653 -.15(ve a d)
-.2 H .353(ozen g).15 F(ate)-.05 E -.1(wa)-.25 G .353(ys to the outside w).1 F
.352(orld; a non-BTL site could choose the closest g)-.1 F(ate)-.05 E -.1(wa)
-.25 G 4.152 -.65(y. T).1 H(he).65 E .308(only restriction w)102 120 R .308
(ould be that all g)-.1 F(ate)-.05 E -.1(wa)-.25 G .308
(ys maintain a consistent vie).1 F 2.808(wo)-.25 G 2.808(ft)390.998 120 S .308
(he domain the)399.916 120 R 2.808(yr)-.15 G(epresent.)468.18 120 Q F0 2.5
(4.4. Logical)87 144 R(Structur)2.5 E(e)-.18 E F1(Logically)127 160.2 Q 3.803
(,d)-.65 G 1.303(omains are or)175.983 160.2 R -.05(ga)-.18 G 1.303
(nized into a tree.).05 F 1.303(There need not be a host actually associated)
6.303 F .462(with each le)102 172.2 R -.15(ve)-.25 G 2.962(li).15 G 2.962(nt)
168.806 172.2 S .462(he tree \212 for e)179.548 172.2 R .462
(xample, there will be no host associated with the name \231UUCP)-.15 F -.7
<2e9a>-1.11 G(Similarly)102 184.2 Q 3.115(,a)-.65 G 3.115(no)148.635 184.2 S
-2.19 -.18(rg a)161.75 184.2 T .614
(nization might group names together for administrati).18 F .914 -.15(ve r)-.25
H .614(easons; for e).15 F .614(xample, the)-.15 F(name)102 196.2 Q
(CAD.research.BigCorp.UUCP)142 212.4 Q(might not actually ha)102 228.6 Q .3
-.15(ve a h)-.2 H(ost representing \231research.).15 E<9a>-.7 E(Ho)127 244.8 Q
(we)-.25 E -.15(ve)-.25 G 1.531 -.4(r, i).15 H 3.231(tm).4 G .731
(ay frequently be con)184.902 244.8 R -.15(ve)-.4 G .731(nient to ha).15 F
1.031 -.15(ve a h)-.2 H .732(ost or hosts that \231represent\232 a domain.).15
F -.15(Fo)102 256.8 S 3.466(re).15 G .966(xample, if a single host e)123.496
256.8 R .966(xists that represents Berk)-.15 F(ele)-.1 E 2.266 -.65(y, t)-.15 H
.966(hen mail from outside Berk).65 F(ele)-.1 E 3.466(yc)-.15 G(an)494.56 256.8
Q(forw)102 268.8 Q .796
(ard mail to that host for further resolution without kno)-.1 F .796(wing Berk)
-.25 F(ele)-.1 E(y')-.15 E 3.296(s\()-.55 G .797(rather v)417.066 268.8 R .797
(olatile\) topol-)-.2 F(ogy)102 280.8 Q 5(.T)-.65 G(his is not unlik)129.96
280.8 Q 2.5(et)-.1 G(he operation of the telephone netw)198.76 280.8 Q(ork.)-.1
E .053(This may also be useful inside certain lar)127 297 R .053(ge domains.)
-.18 F -.15(Fo)5.053 G 2.553(re).15 G .053(xample, at Berk)365.352 297 R(ele)
-.1 E 2.553(yi)-.15 G 2.553(tm)450.801 297 S .053(ay be pre-)463.914 297 R .722
(sumed that most hosts kno)102 309 R 3.222(wa)-.25 G .722
(bout other hosts inside the Berk)225.64 309 R(ele)-.1 E 3.223(yd)-.15 G 3.223
(omain. But)380.825 309 R .723(if the)3.223 F 3.223(yp)-.15 G .723(rocess an)
466.347 309 R .405(address that is unkno)102 321 R .405(wn, the)-.25 F 2.905
(yc)-.15 G .405(an pass it \231upstairs\232 for further e)229.165 321 R 2.905
(xamination. Thus)-.15 F .405(as ne)2.905 F 2.905(wh)-.25 G .405(osts are)
473.325 321 R .488(added only one host \(the domain master\))102 333 R/F2 10
/Times-Italic@0 SF(must)2.989 E F1 .489
(be updated immediately; other hosts can be updated)2.989 F(as con)102 345 Q
-.15(ve)-.4 G(nient.).15 E .583(Ideally this name resolution process w)127
361.2 R .583(ould be performed by a name serv)-.1 F .582
(er \(e.g., [Su82b]\) to)-.15 F -.2(avo)102 373.2 S .507(id unnecessary cop).2
F .507(ying of the message.)-.1 F(Ho)5.507 E(we)-.25 E -.15(ve)-.25 G 1.307 -.4
(r, i).15 H 3.007(nab).4 G .507(atch netw)346.623 373.2 R .508
(ork such as UUCP this could)-.1 F(result in unnecessary delays.)102 385.2 Q F0
2.5(5. COMP)72 409.2 R(ARISON WITH DELIVERMAIL)-.74 E F2(Sendmail)112 425.4 Q
F1(is an outgro)2.5 E(wth of)-.25 E F2(delivermail)2.5 E F1 5(.T)C
(he primary dif)286.18 425.4 Q(ferences are:)-.25 E 12.5(\(1\) Con\214guration)
92 441.6 R .573(information is not compiled in.)3.073 F .572
(This change simpli\214es man)5.572 F 3.072(yo)-.15 G 3.072(ft)433.684 441.6 S
.572(he problems of)442.866 441.6 R(mo)118.66 453.6 Q(ving to other machines.)
-.15 E(It also allo)5 E(ws easy deb)-.25 E(ugging of ne)-.2 E 2.5(wm)-.25 G
(ailers.)388.06 453.6 Q 12.5(\(2\) Address)92 469.8 R .491
(parsing is more \215e)2.991 F 2.991(xible. F)-.15 F .491(or e)-.15 F(xample,)
-.15 E F2(delivermail)2.992 E F1 .492(only supported one g)2.992 F(ate)-.05 E
-.1(wa)-.25 G 2.992(yt).1 G 2.992(oa)481.718 469.8 S -.15(ny)494.15 469.8 S
(netw)118.66 481.8 Q(ork, whereas)-.1 E F2(sendmail)2.5 E F1(can be sensiti)2.5
E .3 -.15(ve t)-.25 H 2.5(oh).15 G(ost names and reroute to dif)310.9 481.8 Q
(ferent g)-.25 E(ate)-.05 E -.1(wa)-.25 G(ys.).1 E 12.5(\(3\) F)92 498 R(orw)
-.15 E 2.878(arding and :include: features eliminate the requirement that the \
system alias \214le be)-.1 F 1.073(writable by an)118.66 510 R 3.573(yu)-.15 G
1.073
(ser \(or that an update program be written, or that the system administration)
191.439 510 R(mak)118.66 522 Q 2.5(ea)-.1 G(ll changes\).)147.16 522 Q(\(4\))92
538.2 Q F2(Sendmail)118.66 538.2 Q F1 .443
(supports message batching across netw)2.944 F .443
(orks when a message is being sent to multiple)-.1 F(recipients.)118.66 550.2 Q
12.5(\(5\) A)92 566.4 R 1.945(mail queue is pro)4.445 F 1.946(vided in)-.15 F
F2(sendmail.)4.446 E F1 1.946(Mail that cannot be deli)6.946 F -.15(ve)-.25 G
1.946(red immediately b).15 F 1.946(ut can)-.2 F .439(potentially be deli)
118.66 578.4 R -.15(ve)-.25 G .438
(red later is stored in this queue for a later retry).15 F 5.438(.T)-.65 G .438
(he queue also pro)404.088 578.4 R .438(vides a)-.15 F -.2(bu)118.66 590.4 S
-.25(ff).2 G .838(er ag).25 F .839(ainst system crashes; after the message has\
 been collected it may be reliably redeli)-.05 F(v-)-.25 E(ered e)118.66 602.4
Q -.15(ve)-.25 G 2.5(ni).15 G 2.5(ft)162.13 602.4 S
(he system crashes during the initial deli)170.74 602.4 Q -.15(ve)-.25 G(ry).15
E(.)-.65 E(\(6\))92 618.6 Q F2(Sendmail)118.66 618.6 Q F1 1.351(uses the netw)
3.851 F 1.351(orking support pro)-.1 F 1.351(vided by 4.2BSD to pro)-.15 F 1.35
(vide a direct interf)-.15 F 1.35(ace net-)-.1 F -.1(wo)118.66 630.6 S .283
(rks such as the ARP).1 F .284
(ANET and/or Ethernet using SMTP \(the Simple Mail T)-.92 F .284
(ransfer Protocol\))-.35 F -.15(ove)118.66 642.6 S 2.5(raT).15 G
(CP/IP connection.)151.68 642.6 Q F0 -1(Ve)72 756 S(rsion 8.2)1 E
(USENIX \255 J)249.805 756 Q(an 83)-.15 E(Last Mod 11/27/93)424.55 756 Q EP
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/F0 10/Times-Roman@0 SF(REFERENCES)264.105 132 Q([Crock)87 148.2 Q 56.73
(er77] Crock)-.1 F(er)-.1 E 3.535(,D)-.4 G 3.535(.H)239.965 148.2 S 1.035(., V)
253.22 148.2 R 1.035(ittal, J. J., Pogran, K. T)-.6 F 1.035
(., and Henderson, D. A. Jr)-.74 F(.,)-.55 E/F1 10/Times-Italic@0 SF(Stan-)
3.535 E(dar)195 160.2 Q 2.627(df)-.37 G .127(or the F)218.927 160.2 R .127
(ormat of ARP)-1.05 F 2.627(AN)-.9 G .128(etwork T)320.112 160.2 R -.2(ex)-.92
G 2.628(tM).2 G(essa)377.018 160.2 Q -.1(ge)-.1 G(s.).1 E F0 .128
(RFC 733, NIC 41952.)5.128 F(In [Feinler78].)195 172.2 Q(No)5 E -.15(ve)-.15 G
(mber 1977.).15 E([Crock)87 188.4 Q 56.73(er82] Crock)-.1 F(er)-.1 E 4.272(,D)
-.4 G 4.272(.H)240.702 188.4 S(.,)254.694 188.4 Q F1(Standar)4.272 E 4.272(df)
-.37 G 1.772(or the F)307.318 188.4 R 1.772(ormat of Arpa Internet T)-1.05 F
-.2(ex)-.92 G 4.271(tM).2 G(essa)471.15 188.4 Q -.1(ge)-.1 G(s.).1 E F0 .025
(RFC 822.)195 200.4 R(Netw)5.025 E .025(ork Information Center)-.1 F 2.526(,S)
-.4 G .026(RI International, Menlo P)363.506 200.4 R .026(ark, Cali-)-.15 F 2.5
(fornia. August)195 212.4 R(1982.)2.5 E 60.51([Feinler78] Feinler)87 228.6 R
2.938(,E)-.4 G .438(., and Postel, J.)234.478 228.6 R(\(eds.\),)5.438 E F1(ARP)
2.938 E .438(ANET Pr)-.9 F .438(otocol Handbook.)-.45 F F0 .438(NIC 7104,)5.438
F(Netw)195 240.6 Q 3.011(ork Information Center)-.1 F 5.511(,S)-.4 G 3.012
(RI International, Menlo P)328.513 240.6 R 3.012(ark, California.)-.15 F(1978.)
195 252.6 Q([No)87 268.8 Q 59.65(witz78] No)-.25 F .479
(witz, D. A., and Lesk, M. E.,)-.25 F F1 2.978(AD)2.978 G .478
(ial-Up Network of UNIX Systems.)344.67 268.8 R F0(Bell)5.478 E 3.528
(Laboratories. In)195 280.8 R 1.029(UNIX Programmer')3.528 F 3.529(sM)-.55 G
1.029(anual, Se)363.524 280.8 R -.15(ve)-.25 G 1.029(nth Edition, V).15 F 1.029
(olume 2.)-1.29 F(August, 1978.)195 292.8 Q 55.5([Schmidt79] Schmidt,)87 309 R
(E.,)2.631 E F1 .131(An Intr)2.631 F .131(oduction to the Berk)-.45 F(ele)-.1 E
2.631(yN)-.3 G(etwork.)382.277 309 Q F0(Uni)5.131 E -.15(ve)-.25 G .131
(rsity of Califor).15 F(-)-.2 E(nia, Berk)195 321 Q(ele)-.1 E 2.5(yC)-.15 G 2.5
(alifornia. 1979.)257.24 321 R 59.95([Shoens79] Shoens,)87 337.2 R(K.,)3.227 E
F1 .728(Mail Refer)3.227 F .728(ence Manual.)-.37 F F0(Uni)5.728 E -.15(ve)-.25
G .728(rsity of California, Berk).15 F(ele)-.1 E 4.528 -.65(y. I)-.15 H(n).65 E
3.478(UNIX Programmer')195 349.2 R 5.977(sM)-.55 G 3.477(anual, Se)297.495
349.2 R -.15(ve)-.25 G 3.477(nth Edition, V).15 F 3.477(olume 2C.)-1.29 F
(December)8.477 E(1979.)195 361.2 Q 52.72([Solomon81] Solomon,)87 377.4 R .251
(M., Landweber)2.75 F 2.751(,L)-.4 G .251(., and Neuhengen, D.,)308.952 377.4 R
F1 .251(The Design of the CSNET)2.751 F .397(Name Server)195 389.4 R(.)-1.11 E
F0 2.896(CS-DN-2. Uni)5.397 F -.15(ve)-.25 G .396(rsity of W).15 F .396
(isconsin, Madison.)-.4 F .396(October 1981.)5.396 F 73.84([Su82a] Su,)87 405.6
R(Za)2.844 E .344(w-Sing, and Postel, Jon,)-.15 F F1 .344
(The Domain Naming Con)2.844 F .344(vention for Internet)-.4 F 2.71
(User Applications.)195 417.6 R F0 5.21(RFC819. Netw)7.71 F 2.71
(ork Information Center)-.1 F 5.21(,S)-.4 G 2.71(RI Interna-)457.14 417.6 R
(tional, Menlo P)195 429.6 Q(ark, California.)-.15 E(August 1982.)5 E 73.28
([Su82b] Su,)87 445.8 R(Za)4.174 E(w-Sing,)-.15 E F1 4.174(AD)4.174 G(istrib)
275.702 445.8 Q 1.675(uted System for Internet Name Service)-.2 F(.)-.15 E F0
(RFC830.)6.675 E(Netw)195 457.8 Q 3.012(ork Information Center)-.1 F 5.512(,S)
-.4 G 3.011(RI International, Menlo P)328.516 457.8 R 3.011(ark, California.)
-.15 F(October 1982.)195 469.8 Q/F2 10/Times-Bold@0 SF(Mail Systems and Addr)72
756 Q(essing in 4.2bsd)-.18 E(9)499 756 Q EP
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