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Diffstat (limited to 'src/global/abounce.c')
| -rw-r--r-- | src/global/abounce.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/src/global/abounce.c b/src/global/abounce.c new file mode 100644 index 0000000..5522f60 --- /dev/null +++ b/src/global/abounce.c @@ -0,0 +1,466 @@ +/*++ +/* NAME +/* abounce 3 +/* SUMMARY +/* asynchronous bounce/defer/trace service client +/* SYNOPSIS +/* #include <abounce.h> +/* +/* void abounce_flush(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* void (*callback)(int status, void *context); +/* void *context; +/* +/* void abounce_flush_verp(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, verp, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* const char *verp; +/* void (*callback)(int status, void *context); +/* void *context; +/* +/* void adefer_flush(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* void (*callback)(int status, void *context); +/* void *context; +/* +/* void adefer_flush_verp(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, verp, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* const char *verp; +/* void (*callback)(int status, void *context); +/* void *context; +/* +/* void adefer_warn(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* void (*callback)(int status, void *context); +/* void *context; +/* +/* void atrace_flush(flags, queue, id, encoding, smtputf8, sender, +/* dsn_envid, dsn_ret, callback, context) +/* int flags; +/* const char *queue; +/* const char *id; +/* const char *encoding; +/* int smtputf8; +/* const char *sender; +/* const char *dsn_envid; +/* int dsn_ret; +/* void (*callback)(int status, void *context); +/* void *context; +/* DESCRIPTION +/* This module implements an asynchronous interface to the +/* bounce/defer/trace service for submitting sender notifications +/* without waiting for completion of the request. +/* +/* abounce_flush() bounces the specified message to +/* the specified sender, including the bounce log that was +/* built with bounce_append(). +/* +/* abounce_flush_verp() is like abounce_flush() but sends +/* one VERP style notification per undeliverable recipient. +/* +/* adefer_flush() bounces the specified message to +/* the specified sender, including the defer log that was +/* built with defer_append(). +/* adefer_flush() requests that the deferred recipients are deleted +/* from the original queue file. +/* +/* adefer_flush_verp() is like adefer_flush() but sends +/* one VERP style notification per undeliverable recipient. +/* +/* adefer_warn() sends a "mail is delayed" notification to +/* the specified sender, including the defer log that was +/* built with defer_append(). +/* +/* atrace_flush() returns the specified message to the specified +/* sender, including the message delivery record log that was +/* built with vtrace_append(). +/* +/* Arguments: +/* .IP flags +/* The bitwise OR of zero or more of the following (specify +/* BOUNCE_FLAG_NONE to request no special processing): +/* .RS +/* .IP BOUNCE_FLAG_CLEAN +/* Delete the bounce log in case of an error (as in: pretend +/* that we never even tried to bounce this message). +/* .IP BOUNCE_FLAG_DELRCPT +/* When specified with a flush operation, request that +/* recipients be deleted from the queue file. +/* +/* Note: the bounce daemon ignores this request when the +/* recipient queue file offset is <= 0. +/* .IP BOUNCE_FLAG_COPY +/* Request that a postmaster copy is sent. +/* .RE +/* .IP queue +/* The message queue name of the original message file. +/* .IP id +/* The message queue id if the original message file. The bounce log +/* file has the same name as the original message file. +/* .IP encoding +/* The body content encoding: MAIL_ATTR_ENC_{7BIT,8BIT,NONE}. +/* .IP smtputf8 +/* The level of SMTPUTF8 support (to be defined). +/* .IP sender +/* The sender envelope address. +/* .IP dsn_envid +/* Optional DSN envelope ID. +/* .IP ret +/* Optional DSN return full/headers option. +/* .IP verp +/* VERP delimiter characters. +/* .IP callback +/* Name of a routine that receives the notification status as +/* documented for bounce_flush() or defer_flush(). +/* .IP context +/* Application-specific context that is passed through to the +/* callback routine. Use proper casts or the world will come +/* to an end. +/* DIAGNOSTICS +/* In case of success, these functions log the action, and return a +/* zero result via the callback routine. Otherwise, the functions +/* return a non-zero result via the callback routine, and when +/* BOUNCE_FLAG_CLEAN is disabled, log that message delivery is deferred. +/* 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 +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <events.h> +#include <vstream.h> + +/* Global library. */ + +#include <mail_params.h> +#include <mail_proto.h> +#include <abounce.h> + +/* Application-specific. */ + + /* + * Each bounce/defer flush/warn request is implemented by sending the + * request to the bounce/defer server, and by creating a pseudo thread that + * suspends itself until the server replies (or dies). Upon wakeup, the + * pseudo thread delivers the request completion status to the application + * and destroys itself. The structure below maintains all the necessary + * request state while the pseudo thread is suspended. + */ +typedef struct { + int command; /* bounce request type */ + int flags; /* bounce options */ + char *id; /* queue ID for logging */ + VSTRING *request; /* serialized request */ + ABOUNCE_FN callback; /* application callback */ + void *context; /* application context */ + VSTREAM *fp; /* server I/O handle */ +} ABOUNCE_STATE; + + /* + * Encapsulate common code. + */ +#define ABOUNCE_EVENT_ENABLE(fd, callback, context, timeout) do { \ + event_enable_read((fd), (callback), (context)); \ + event_request_timer((callback), (context), (timeout)); \ + } while (0) + + /* + * If we set the reply timeout too short, then we make the problem worse by + * increasing overload. With 1000s timeout mail will keep flowing, but there + * will be a large number of blocked bounce processes, and some resource is + * likely to run out. + */ +#define ABOUNCE_TIMEOUT 1000 + + /* + * The initial buffer size for a serialized request. + */ +#define ABOUNCE_BUFSIZE VSTREAM_BUFSIZE + + /* + * We share most of the verp and non-verp code paths. + */ +#define ABOUNCE_NO_VERP ((char *) 0) + + /* + * SLMs. + */ +#define STR(x) vstring_str(x) +#define LEN(x) VSTRING_LEN(x) + +/* abounce_done - deliver status to application and clean up pseudo thread */ + +static void abounce_done(ABOUNCE_STATE *ap, int status) +{ + if (ap->fp) { + event_disable_readwrite(vstream_fileno(ap->fp)); + (void) vstream_fclose(ap->fp); + } + if (status != 0 && (ap->flags & BOUNCE_FLAG_CLEAN) == 0) + msg_info("%s: status=deferred (%s failed)", ap->id, + ap->command == BOUNCE_CMD_FLUSH ? "bounce" : + ap->command == BOUNCE_CMD_WARN ? "delay warning" : + ap->command == BOUNCE_CMD_VERP ? "verp" : + ap->command == BOUNCE_CMD_TRACE ? "trace" : + "whatever"); + ap->callback(status, ap->context); + myfree(ap->id); + vstring_free(ap->request); + myfree((void *) ap); +} + +/* abounce_receive - receive server reply */ + +static void abounce_receive(int event, void *context) +{ + ABOUNCE_STATE *ap = (ABOUNCE_STATE *) context; + int status; + + if (event != EVENT_TIME) + event_cancel_timer(abounce_receive, context); + + if (event == EVENT_READ + && attr_scan(ap->fp, ATTR_FLAG_STRICT, + RECV_ATTR_INT(MAIL_ATTR_STATUS, &status), + ATTR_TYPE_END) == 1) { + abounce_done(ap, status); + } else { + abounce_done(ap, -1); + } +} + +/* abounce_send - send the request and suspend until the server replies */ + +static void abounce_send(int event, void *context) +{ + ABOUNCE_STATE *ap = (ABOUNCE_STATE *) context; + + /* + * Receive the server's protocol name announcement. At this point the + * server is ready to receive a request without blocking the sender. Send + * the request and suspend until the server replies (or dies). + */ + if (event != EVENT_TIME) + event_cancel_timer(abounce_send, context); + + non_blocking(vstream_fileno(ap->fp), BLOCKING); + if (event == EVENT_READ + && attr_scan(ap->fp, ATTR_FLAG_STRICT, + RECV_ATTR_STREQ(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_BOUNCE), + ATTR_TYPE_END) == 0 + && vstream_fwrite(ap->fp, STR(ap->request), + LEN(ap->request)) == LEN(ap->request) + && vstream_fflush(ap->fp) == 0) { + ABOUNCE_EVENT_ENABLE(vstream_fileno(ap->fp), abounce_receive, + (void *) ap, ABOUNCE_TIMEOUT); + } else { + abounce_done(ap, -1); + } +} + +/* abounce_connect - connect and suspend until the server replies */ + +static void abounce_connect(const char *class, const char *service, + int command, int flags, + const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, + const char *dsn_envid, int dsn_ret, + const char *verp, ABOUNCE_FN callback, + void *context) +{ + ABOUNCE_STATE *ap; + + /* + * Save pseudo thread state. Connect to the server. Prior to Postfix 3.6 + * the asynchronous bounce flush/warn client called mail_connect_wait() + * which sleeps and retries several times before terminating with a fatal + * error. This block-and-sleep behavior was not consistent with a) the + * rest of the code in this module, and with b) the synchronous bounce + * client which gives up immediately. It should be safe to give up + * immediately because that leaves the bounce/defer/trace logs in the + * queue. In particular, this should not increase the simultaneous number + * of asynchronous bounce/defer/trace flush/warn requests that are in + * flight. + */ + ap = (ABOUNCE_STATE *) mymalloc(sizeof(*ap)); + ap->command = command; + ap->flags = flags; + ap->id = mystrdup(id); + ap->request = vstring_alloc(ABOUNCE_BUFSIZE); + ap->callback = callback; + ap->context = context; + ap->fp = mail_connect(class, service, NON_BLOCKING); + + /* + * Format the request now, so that we don't have to save a lot of + * arguments now and format the request later. + */ + if (ap->fp != 0) { + /* Note: all code paths must terminate or enable I/O events. */ + VSTREAM *mp = vstream_memopen(ap->request, O_WRONLY); + + if (attr_print(mp, ATTR_FLAG_MORE, + SEND_ATTR_INT(MAIL_ATTR_NREQ, command), + SEND_ATTR_INT(MAIL_ATTR_FLAGS, flags), + SEND_ATTR_STR(MAIL_ATTR_QUEUE, queue), + SEND_ATTR_STR(MAIL_ATTR_QUEUEID, id), + SEND_ATTR_STR(MAIL_ATTR_ENCODING, encoding), + SEND_ATTR_INT(MAIL_ATTR_SMTPUTF8, smtputf8), + SEND_ATTR_STR(MAIL_ATTR_SENDER, sender), + SEND_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid), + SEND_ATTR_INT(MAIL_ATTR_DSN_RET, dsn_ret), + ATTR_TYPE_END) != 0 + || (verp != 0 + && attr_print(mp, ATTR_FLAG_MORE, + SEND_ATTR_STR(MAIL_ATTR_VERPDL, verp), + ATTR_TYPE_END) != 0) + || attr_print(mp, ATTR_FLAG_NONE, + ATTR_TYPE_END) != 0 + || vstream_fclose(mp) != 0) + msg_panic("abounce_connect: write request to memory stream: %m"); + + /* + * Suspend until the server replies (or dies). + */ + ABOUNCE_EVENT_ENABLE(vstream_fileno(ap->fp), abounce_send, + (void *) ap, ABOUNCE_TIMEOUT); + } else { + abounce_done(ap, -1); + } +} + +/* abounce_flush_verp - asynchronous bounce flush */ + +void abounce_flush_verp(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, const char *verp, + ABOUNCE_FN callback, + void *context) +{ + abounce_connect(MAIL_CLASS_PRIVATE, var_bounce_service, + BOUNCE_CMD_VERP, flags, queue, id, encoding, smtputf8, + sender, dsn_envid, dsn_ret, verp, callback, context); +} + +/* adefer_flush_verp - asynchronous defer flush */ + +void adefer_flush_verp(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, const char *verp, + ABOUNCE_FN callback, void *context) +{ + flags |= BOUNCE_FLAG_DELRCPT; + abounce_connect(MAIL_CLASS_PRIVATE, var_defer_service, + BOUNCE_CMD_VERP, flags, queue, id, encoding, smtputf8, + sender, dsn_envid, dsn_ret, verp, callback, context); +} + +/* abounce_flush - asynchronous bounce flush */ + +void abounce_flush(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, ABOUNCE_FN callback, + void *context) +{ + abounce_connect(MAIL_CLASS_PRIVATE, var_bounce_service, BOUNCE_CMD_FLUSH, + flags, queue, id, encoding, smtputf8, sender, dsn_envid, + dsn_ret, ABOUNCE_NO_VERP, callback, context); +} + +/* adefer_flush - asynchronous defer flush */ + +void adefer_flush(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, ABOUNCE_FN callback, void *context) +{ + flags |= BOUNCE_FLAG_DELRCPT; + abounce_connect(MAIL_CLASS_PRIVATE, var_defer_service, BOUNCE_CMD_FLUSH, + flags, queue, id, encoding, smtputf8, sender, dsn_envid, + dsn_ret, ABOUNCE_NO_VERP, callback, context); +} + +/* adefer_warn - send copy of defer log to sender as warning bounce */ + +void adefer_warn(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, ABOUNCE_FN callback, void *context) +{ + abounce_connect(MAIL_CLASS_PRIVATE, var_defer_service, BOUNCE_CMD_WARN, + flags, queue, id, encoding, smtputf8, sender, dsn_envid, + dsn_ret, ABOUNCE_NO_VERP, callback, context); +} + +/* atrace_flush - asynchronous trace flush */ + +void atrace_flush(int flags, const char *queue, const char *id, + const char *encoding, int smtputf8, + const char *sender, const char *dsn_envid, + int dsn_ret, ABOUNCE_FN callback, void *context) +{ + abounce_connect(MAIL_CLASS_PRIVATE, var_trace_service, BOUNCE_CMD_TRACE, + flags, queue, id, encoding, smtputf8, sender, dsn_envid, + dsn_ret, ABOUNCE_NO_VERP, callback, context); +} |