Mercurial > hg > mlmmj

comparison README.postfix @ 780:ddae562f7cf0

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Document why 'nobody' is inappropriate and capitalise a few things
author Ben Schmidt
date Mon, 15 Nov 2010 10:11:28 +1100
parents fdc57c9e5f56
children 58d726e86650
comparison
equal deleted inserted replaced
779:93d445688ebe 780:ddae562f7cf0
1 README.postfix Dec 16th 2009 1 README.postfix Dec 16th 2009
2 2
3 POSTFIX ISSUES 3 POSTFIX ISSUES
4 4
5 The main issue with Postfix and mlmmj is the mlmmj requirement that 5 The main issue with Postfix and Mlmmj is the Mlmmj requirement that
6 the mlmmj executables must be executed by root or the owner of the 6 the Mlmmj executables must be executed by root or the owner of the
7 list directory. 7 list directory.
8 8
9 This is at odds with Postfix. The standard local delivery mechanism 9 This is at odds with Postfix. The standard local delivery mechanism
10 for Postfix is local(8) that ships with Postfix. According to 10 for Postfix is local(8) that ships with Postfix. According to
11 local(8) delivery to external programs is done on behalf of the 11 local(8) delivery to external programs is done on behalf of the
12 receiving user. But when delivering to a program without using a 12 receiving user. But when delivering to a program without using a
17 local(8) daemon will use the owner of the :include: file from the 17 local(8) daemon will use the owner of the :include: file from the
18 aliases file. But this is a problem too. By default :include: 18 aliases file. But this is a problem too. By default :include:
19 files are disabled as a security precaution in aliases files for 19 files are disabled as a security precaution in aliases files for
20 delivering to external programs. 20 delivering to external programs.
21 21
22 This leaves us with a conundrum on how to execute the mlmmj 22 So Postfix then falls back to executing with the user specified by
23 executables as an 'mlmmj' user without using alias files. One 23 the configuration option 'default_privs'. The default setting for
24 answer is to use a postfix transport. 24 this option is the user 'nobody'. You can make Mlmmj work by having
25 your lists owned by 'nobody', but this is not recommended. Other
26 programs and daemons may use 'nobody' as a user who should not have
27 access to anything; most notably, some NFS implementations use this
28 user when somebody connects but fails to authenticate. Such users
29 should not be able to access your mailing lists. Changing
30 'default_privs' to an 'mlmmj' user may open other security holes,
31 and may not be appropriate if Postfix is used for other external
32 programs besides Mlmmj.
33
34 This leaves us with a conundrum on how to execute the Mlmmj
35 executables as an 'mlmmj' user. One answer is to use a Postfix
36 transport.
25 37
26 First we'll get the 'mlmmj' user setup and then move onto the 38 First we'll get the 'mlmmj' user setup and then move onto the
27 postfix configuration: 39 Postfix configuration:
28 40
29 MLMMJ SETUP 41 MLMMJ SETUP
30 42
31 Create a 'mlmmj' user that will own all the lists. Use whatever 43 Create a 'mlmmj' user that will own all the lists. Use whatever
32 user creation app/script is provided by your system. Generally 44 user creation app/script is provided by your system. Generally
33 'useradd'. 45 'useradd'.
34 46
35 Create the spool directory that is owned by the 'mlmmj' user. 47 Create the spool directory that is owned by the 'mlmmj' user.
41 53
42 Create a mailing list using mlmmj-make-ml. Make sure to use the 54 Create a mailing list using mlmmj-make-ml. Make sure to use the
43 -s flag to set the spool directory if it isn't /var/spool/mlmmj 55 -s flag to set the spool directory if it isn't /var/spool/mlmmj
44 56
45 POSTFIX SETUP 57 POSTFIX SETUP
46 58
47 First thing is to make sure that the postfix server accepts mail for 59 First thing is to make sure that the postfix server accepts mail for
48 the mailing lists. For a server that handles mail for multiple 60 the mailing lists. For a server that handles mail for multiple
49 domains, this is done with a 'virtual_alias_map'. This is how I'll 61 domains, this is done with a 'virtual_alias_map'. This is how I'll
50 demonstrate. 62 demonstrate.
51 63
52 Add a virtual_alias_map file to main.cf configuration. We'll use a 64 Add a virtual_alias_map file to main.cf configuration. We'll use a
53 regular expression map since we need to be able to match all the 65 regular expression map since we need to be able to match all the
54 various mjmml delimiter addresses (list-subscribe, list-unsubscribe, 66 various Mlmmj delimiter addresses (list-subscribe, list-unsubscribe,
55 etc) 67 confsub-0123456789abcdef, etc.).
56 68
57 main.cf: 69 main.cf:
58 virtual_alias_maps = hash:/etc/postfix/virtual, 70 virtual_alias_maps = hash:/etc/postfix/virtual,
59 regexp:/var/spool/mlmmj/virtual.regexp 71 regexp:/var/spool/mlmmj/virtual.regexp
60 72
61 /var/spool/mlmmj/virtual.regexp: 73 /var/spool/mlmmj/virtual.regexp:
62 /^(mlmmj-test.*)@example\.com$/ ${1} 74 /^(mlmmj-test.*)@example\.com$/ ${1}
63 /^(another-list.*)@sample\.com$/ ${1} 75 /^(another-list.*)@sample\.com$/ ${1}
64 76
65 One line needs to be in the virtual map for each list the 'mlmmj' id 77 One line needs to be in the virtual map for each list the 'mlmmj' id
70 If you want to host multiple domains in a hierarchical structure, 82 If you want to host multiple domains in a hierarchical structure,
71 you can alternatively use: 83 you can alternatively use:
72 84
73 /^(list-name.*)@(domain\.com)$/ domain--${1} 85 /^(list-name.*)@(domain\.com)$/ domain--${1}
74 86
75 Next we make sure that postfix can invoke the mlmmj executables as 87 Next we make sure that Postfix can invoke the mlmmj executables as
76 the 'mlmmj' user. This is where the transport map comes in. So we 88 the 'mlmmj' user. This is where the transport map comes in. So we
77 add a transport map and a configuration option that instructs the 89 add a transport map and a configuration option that instructs the
78 transport to only deliver one file at a time. See transport(5) for 90 transport to only deliver one file at a time. See transport(5) for
79 more information on transports. 91 more information on transports.
80 92
81 main.cf: 93 main.cf:
82 transport_maps = regexp:/var/spool/mlmmj/transport 94 transport_maps = regexp:/var/spool/mlmmj/transport
83 mlmmj_destination_recipient_limit = 1 95 mlmmj_destination_recipient_limit = 1
84 96
85 /var/spool/mlmmj/transport: 97 /var/spool/mlmmj/transport:
86 /^(list-test).*$/ mlmmj:list-test 98 /^(list-test).*$/ mlmmj:list-test
87 /^(another-list).*$/ mlmmj:another-list 99 /^(another-list).*$/ mlmmj:another-list
88 100
89 What this transport file says, is that any message destined for an 101 What this transport file says, is that any message destined for an
95 For the hierarchical multi-domain solution, use this variant: 107 For the hierarchical multi-domain solution, use this variant:
96 108
97 /^(domain--list-name).*$/ mlmmj:domain/list-name 109 /^(domain--list-name).*$/ mlmmj:domain/list-name
98 110
99 Now we setup the 'mlmmj' transport. The 'mlmmj' in mlmmj:$1 above 111 Now we setup the 'mlmmj' transport. The 'mlmmj' in mlmmj:$1 above
100 indicates a transport listed in the postfix master.cf file. We are 112 indicates a transport listed in the Postfix master.cf file. We are
101 just going to create a transport called 'mlmmj' but it is nothing 113 just going to create a transport called 'mlmmj' but it is nothing
102 more than a pipe(8) to the mlmmj-receive program that is invoked as 114 more than a pipe(8) to the mlmmj-receive program that is invoked as
103 the 'mlmmj' user. 115 the 'mlmmj' user.
104 116
105 master.cf: 117 master.cf:
106 # mlmmj mailing lists 118 # mlmmj mailing lists
107 mlmmj unix - n n - - pipe 119 mlmmj unix - n n - - pipe
108 flags=DORhu user=mlmmj argv=/usr/local/bin/mlmmj-receive -F -L /var/spool/mlmmj/$nexthop/ 120 flags=DORhu user=mlmmj argv=/usr/local/bin/mlmmj-receive -F -L /var/spool/mlmmj/$nexthop/
109 121
110 This takes the pipe(8) postfix delivery agent and tells it to invoke 122 This takes the pipe(8) Postfix delivery agent and tells it to invoke
111 '/usr/local/bin/mlmmj-receive' as the 'mlmmj' user and pipe the 123 '/usr/local/bin/mlmmj-receive' as the 'mlmmj' user and pipe the
112 email to it on stdin. This mode of transportation is given the name 124 email to it on stdin. This mode of transportation is given the name
113 'mlmmj'. 125 'mlmmj'.
114 126
115 The 'flags' parameter to pipe(8) is pretty critical here. In 127 The 'flags' parameter to pipe(8) is pretty critical here. In
127 $nexthop will get set to the name of the mailing list (or domain 139 $nexthop will get set to the name of the mailing list (or domain
128 and name). Your list directories, then, should be at 140 and name). Your list directories, then, should be at
129 /var/spool/mlmmj/list-name as usual, or for the hierarchical 141 /var/spool/mlmmj/list-name as usual, or for the hierarchical
130 multi-domain version, in /var/spool/mlmmj/domain/list-name. 142 multi-domain version, in /var/spool/mlmmj/domain/list-name.
131 143
132 Restart postfix and enjoy your new lists. 144 Restart Postfix and enjoy your new lists.
133 145
134 146