diff options
Diffstat (limited to 'src/local/recipient.c')
| -rw-r--r-- | src/local/recipient.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/src/local/recipient.c b/src/local/recipient.c new file mode 100644 index 0000000..e3f4d1c --- /dev/null +++ b/src/local/recipient.c @@ -0,0 +1,307 @@ +/*++ +/* NAME +/* recipient 3 +/* SUMMARY +/* deliver to one local recipient +/* SYNOPSIS +/* #include "local.h" +/* +/* int deliver_recipient(state, usr_attr) +/* LOCAL_STATE state; +/* USER_ATTR *usr_attr; +/* DESCRIPTION +/* deliver_recipient() delivers a message to a local recipient. +/* It is called initially when the queue manager requests +/* delivery to a local recipient, and is called recursively +/* when an alias or forward file expands to a local recipient. +/* +/* When called recursively with, for example, a result from alias +/* or forward file expansion, aliases are expanded immediately, +/* but mail for non-alias destinations is submitted as a new +/* message, so that each recipient has a dedicated queue file +/* message delivery status record (in a shared queue file). +/* +/* When the \fIrecipient_delimiter\fR configuration parameter +/* is set, it is used to separate cookies off recipient names. +/* A common setting is to have "recipient_delimiter = +" +/* so that mail for \fIuser+foo\fR is delivered to \fIuser\fR, +/* with a "Delivered-To: user+foo@domain" header line. +/* +/* Arguments: +/* .IP state +/* The attributes that specify the message, sender, and more. +/* Attributes describing alias, include or forward expansion. +/* A table with the results from expanding aliases or lists. +/* A table with delivered-to: addresses taken from the message. +/* .IP usr_attr +/* Attributes describing user rights and environment. +/* DIAGNOSTICS +/* deliver_recipient() returns non-zero when delivery should be +/* tried again. +/* BUGS +/* Mutually-recursive aliases or $HOME/.forward files aren't +/* detected when they could be. The resulting mail forwarding loop +/* is broken by the use of the Delivered-To: message header. +/* SEE ALSO +/* alias(3) delivery to aliases +/* mailbox(3) delivery to mailbox +/* dotforward(3) delivery to destinations in .forward file +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <sys/stat.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <htable.h> +#include <split_at.h> +#include <stringops.h> +#include <dict.h> +#include <stat_as.h> + +/* Global library. */ + +#include <bounce.h> +#include <defer.h> +#include <mail_params.h> +#include <split_addr.h> +#include <strip_addr.h> +#include <ext_prop.h> +#include <mypwd.h> +#include <canon_addr.h> + +/* Application-specific. */ + +#include "local.h" + +/* deliver_switch - branch on recipient type */ + +static int deliver_switch(LOCAL_STATE state, USER_ATTR usr_attr) +{ + const char *myname = "deliver_switch"; + int status = 0; + struct stat st; + struct mypasswd *mypwd; + + /* + * Make verbose logging easier to understand. + */ + state.level++; + if (msg_verbose) + MSG_LOG_STATE(myname, state); + + + /* + * \user is special: it means don't do any alias or forward expansion. + * + * XXX This code currently does not work due to revision of the RFC822 + * address parser. \user should be permitted only in locally specified + * aliases, includes or forward files. + * + * XXX Should test for presence of user home directory. + */ + if (state.msg_attr.rcpt.address[0] == '\\') { + state.msg_attr.rcpt.address++, state.msg_attr.local++, state.msg_attr.user++; + if (deliver_mailbox(state, usr_attr, &status) == 0) + status = deliver_unknown(state, usr_attr); + return (status); + } + + /* + * Otherwise, alias expansion has highest precedence. First look up the + * full localpart, then the bare user. Obey the address extension + * propagation policy. + */ + state.msg_attr.unmatched = 0; + if (deliver_alias(state, usr_attr, state.msg_attr.local, &status)) + return (status); + if (state.msg_attr.extension != 0) { + if (local_ext_prop_mask & EXT_PROP_ALIAS) + state.msg_attr.unmatched = state.msg_attr.extension; + if (deliver_alias(state, usr_attr, state.msg_attr.user, &status)) + return (status); + state.msg_attr.unmatched = state.msg_attr.extension; + } + + /* + * Special case for mail locally forwarded or aliased to a different + * local address. Resubmit the message via the cleanup service, so that + * each recipient gets a separate delivery queue file status record in + * the new queue file. The downside of this approach is that mutually + * recursive .forward files cause a mail forwarding loop. Fortunately, + * the loop can be broken by the use of the Delivered-To: message header. + * + * The code below must not trigger on mail sent to an alias that has no + * owner- companion, so that mail for an alias first.last->username is + * delivered directly, instead of going through username->first.last + * canonical mappings in the cleanup service. The downside of this + * approach is that recipients in the expansion of an alias without + * owner- won't have separate delivery queue file status records, because + * for them, the message won't be resubmitted as a new queue file. + * + * Do something sensible on systems that receive mail for multiple domains, + * such as primary.name and secondary.name. Don't resubmit the message + * when mail for `user@secondary.name' is delivered to a .forward file + * that lists `user' or `user@primary.name'. We already know that the + * recipient domain is local, so we only have to compare local parts. + */ + if (state.msg_attr.owner != 0 + && strcasecmp_utf8(state.msg_attr.owner, state.msg_attr.user) != 0) + return (deliver_indirect(state)); + + /* + * Always forward recipients in :include: files. + */ + if (state.msg_attr.exp_type == EXPAND_TYPE_INCL) + return (deliver_indirect(state)); + + /* + * Delivery to local user. First try expansion of the recipient's + * $HOME/.forward file, then mailbox delivery. Back off when the user's + * home directory does not exist. + */ + mypwd = 0; + if (var_stat_home_dir + && (errno = mypwnam_err(state.msg_attr.user, &mypwd)) != 0) { + msg_warn("error looking up passwd info for %s: %m", + state.msg_attr.user); + dsb_simple(state.msg_attr.why, "4.0.0", "user lookup error"); + return (defer_append(BOUNCE_FLAGS(state.request), + BOUNCE_ATTR(state.msg_attr))); + } + if (mypwd != 0) { + if (stat_as(mypwd->pw_dir, &st, mypwd->pw_uid, mypwd->pw_gid) < 0) { + dsb_simple(state.msg_attr.why, "4.3.0", + "cannot access home directory %s: %m", mypwd->pw_dir); + mypwfree(mypwd); + return (defer_append(BOUNCE_FLAGS(state.request), + BOUNCE_ATTR(state.msg_attr))); + } + mypwfree(mypwd); + } + if (deliver_dotforward(state, usr_attr, &status) == 0 + && deliver_mailbox(state, usr_attr, &status) == 0) + status = deliver_unknown(state, usr_attr); + return (status); +} + +/* deliver_recipient - deliver one local recipient */ + +int deliver_recipient(LOCAL_STATE state, USER_ATTR usr_attr) +{ + const char *myname = "deliver_recipient"; + VSTRING *folded; + int rcpt_stat; + + /* + * Make verbose logging easier to understand. + */ + state.level++; + if (msg_verbose) + MSG_LOG_STATE(myname, state); + + /* + * Duplicate filter. + */ + if (been_here(state.dup_filter, "recipient %d %s", + state.level, state.msg_attr.rcpt.address)) + return (0); + + /* + * With each level of recursion, detect and break external message + * forwarding loops. + * + * If the looping recipient address has an owner- alias, send the error + * report there instead. + * + * XXX A delivery agent cannot change the envelope sender address for + * bouncing. As a workaround we use a one-recipient bounce procedure. + * + * The proper fix would be to record in the bounce logfile an error return + * address for each individual recipient. This would also eliminate the + * need for VERP specific bouncing code, at the cost of complicating the + * normal bounce sending procedure, but would simplify the code below. + */ + if (delivered_hdr_find(state.loop_info, state.msg_attr.rcpt.address)) { + dsb_simple(state.msg_attr.why, "5.4.6", "mail forwarding loop for %s", + state.msg_attr.rcpt.address); + /* Account for possible owner- sender address override. */ + return (bounce_workaround(state)); + } + + /* + * Set up the recipient-specific attributes. If this is forwarded mail, + * leave the delivered attribute alone, so that the forwarded message + * will show the correct forwarding recipient. + */ + if (state.msg_attr.delivered == 0) + state.msg_attr.delivered = state.msg_attr.rcpt.address; + folded = vstring_alloc(100); + state.msg_attr.local = casefold(folded, state.msg_attr.rcpt.address); + if ((state.msg_attr.domain = split_at_right(state.msg_attr.local, '@')) == 0) + msg_warn("no @ in recipient address: %s", state.msg_attr.local); + + /* + * Address extension management. + * + * XXX Fix 20100422, finalized 20100529: it is too error-prone to + * distinguish between "no extension" and "no valid extension", so we + * drop an invalid extension from the recipient address local-part. + */ + state.msg_attr.user = mystrdup(state.msg_attr.local); + if (*var_rcpt_delim) { + state.msg_attr.extension = + split_addr(state.msg_attr.user, var_rcpt_delim); + if (state.msg_attr.extension && strchr(state.msg_attr.extension, '/')) { + msg_warn("%s: address with illegal extension: %s", + state.msg_attr.queue_id, state.msg_attr.local); + state.msg_attr.extension = 0; + /* XXX Can't myfree + mystrdup, must truncate instead. */ + state.msg_attr.local[strlen(state.msg_attr.user)] = 0; + /* Truncating is safe. The code below rejects null usernames. */ + } + } else + state.msg_attr.extension = 0; + state.msg_attr.unmatched = state.msg_attr.extension; + + /* + * Do not allow null usernames. + */ + if (state.msg_attr.user[0] == 0) { + dsb_simple(state.msg_attr.why, "5.1.3", + "null username in \"%s\"", state.msg_attr.rcpt.address); + return (bounce_append(BOUNCE_FLAGS(state.request), + BOUNCE_ATTR(state.msg_attr))); + } + + /* + * Run the recipient through the delivery switch. + */ + if (msg_verbose) + deliver_attr_dump(&state.msg_attr); + rcpt_stat = deliver_switch(state, usr_attr); + + /* + * Clean up. + */ + vstring_free(folded); + myfree(state.msg_attr.user); + + return (rcpt_stat); +} |