diff options
Diffstat (limited to 'src/global/deliver_request.c')
| -rw-r--r-- | src/global/deliver_request.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/src/global/deliver_request.c b/src/global/deliver_request.c new file mode 100644 index 0000000..7bc5553 --- /dev/null +++ b/src/global/deliver_request.c @@ -0,0 +1,484 @@ +/*++ +/* NAME +/* deliver_request 3 +/* SUMMARY +/* mail delivery request protocol, server side +/* SYNOPSIS +/* #include <deliver_request.h> +/* +/* typedef struct DELIVER_REQUEST { +/* .in +5 +/* VSTREAM *fp; +/* int flags; +/* char *queue_name; +/* char *queue_id; +/* long data_offset; +/* long data_size; +/* char *nexthop; +/* char *encoding; +/* char *sender; +/* MSG_STATS msg_stats; +/* RECIPIENT_LIST rcpt_list; +/* DSN *hop_status; +/* char *client_name; +/* char *client_addr; +/* char *client_port; +/* char *client_proto; +/* char *client_helo; +/* char *sasl_method; +/* char *sasl_username; +/* char *sasl_sender; +/* char *log_ident; +/* char *rewrite_context; +/* char *dsn_envid; +/* int dsn_ret; +/* .in -5 +/* } DELIVER_REQUEST; +/* +/* DELIVER_REQUEST *deliver_request_read(stream) +/* VSTREAM *stream; +/* +/* void deliver_request_done(stream, request, status) +/* VSTREAM *stream; +/* DELIVER_REQUEST *request; +/* int status; +/* DESCRIPTION +/* This module implements the delivery agent side of the `queue manager +/* to delivery agent' protocol. In this game, the queue manager is +/* the client, while the delivery agent is the server. +/* +/* deliver_request_read() reads a client message delivery request, +/* opens the queue file, and acquires a shared lock. +/* A null result means that the client sent bad information or that +/* it went away unexpectedly. +/* +/* The \fBflags\fR structure member is the bit-wise OR of zero or more +/* of the following: +/* .IP \fBDEL_REQ_FLAG_SUCCESS\fR +/* Delete successful recipients from the queue file. +/* +/* Note: currently, this also controls whether bounced recipients +/* are deleted. +/* +/* Note: the deliver_completed() function ignores this request +/* when the recipient queue file offset is -1. +/* .IP \fBDEL_REQ_FLAG_BOUNCE\fR +/* Delete bounced recipients from the queue file. Currently, +/* this flag is non-functional. +/* .PP +/* The \fBDEL_REQ_FLAG_DEFLT\fR constant provides a convenient shorthand +/* for the most common case: delete successful and bounced recipients. +/* +/* The \fIhop_status\fR member must be updated by the caller +/* when all delivery to the destination in \fInexthop\fR should +/* be deferred. This member is passed to dsn_free(). +/* +/* deliver_request_done() reports the delivery status back to the +/* client, including the optional \fIhop_status\fR etc. information, +/* closes the queue file, +/* and destroys the DELIVER_REQUEST structure. The result is +/* non-zero when the status could not be reported to the client. +/* DIAGNOSTICS +/* Warnings: bad data sent by the client. Fatal errors: out of +/* memory, queue file open errors. +/* SEE ALSO +/* attr_scan(3) low-level intra-mail input routines +/* 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> +#include <sys/stat.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> + +/* Utility library. */ + +#include <msg.h> +#include <vstream.h> +#include <vstring.h> +#include <mymalloc.h> +#include <iostuff.h> +#include <myflock.h> + +/* Global library. */ + +#include "mail_queue.h" +#include "mail_proto.h" +#include "mail_open_ok.h" +#include "recipient_list.h" +#include "dsn.h" +#include "dsn_print.h" +#include "deliver_request.h" +#include "rcpt_buf.h" + +/* deliver_request_initial - send initial status code */ + +static int deliver_request_initial(VSTREAM *stream) +{ + int err; + + /* + * The master processes runs a finite number of delivery agent processes + * to handle service requests. Thus, a delivery agent process must send + * something to inform the queue manager that it is ready to receive a + * delivery request; otherwise the queue manager could block in write(). + */ + if (msg_verbose) + msg_info("deliver_request_initial: send initial response"); + attr_print(stream, ATTR_FLAG_NONE, + SEND_ATTR_STR(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_DELIVER), + ATTR_TYPE_END); + if ((err = vstream_fflush(stream)) != 0) + if (msg_verbose) + msg_warn("send initial response: %m"); + return (err); +} + +/* deliver_request_final - send final delivery request status */ + +static int deliver_request_final(VSTREAM *stream, DELIVER_REQUEST *request, + int status) +{ + DSN *hop_status; + int err; + + /* XXX This DSN structure initialization bypasses integrity checks. */ + static DSN dummy_dsn = {"", "", "", "", "", "", ""}; + + /* + * Send the status and the optional reason. + */ + if ((hop_status = request->hop_status) == 0) + hop_status = &dummy_dsn; + if (msg_verbose) + msg_info("deliver_request_final: send: \"%s\" %d", + hop_status->reason, status); + attr_print(stream, ATTR_FLAG_NONE, + SEND_ATTR_FUNC(dsn_print, (const void *) hop_status), + SEND_ATTR_INT(MAIL_ATTR_STATUS, status), + ATTR_TYPE_END); + if ((err = vstream_fflush(stream)) != 0) + if (msg_verbose) + msg_warn("send final status: %m"); + + /* + * With some UNIX systems, stream sockets lose data when you close them + * immediately after writing to them. That is not how sockets are + * supposed to behave! The workaround is to wait until the receiver + * closes the connection. Calling VSTREAM_GETC() has the benefit of using + * whatever timeout is specified in the ipc_timeout parameter. + */ + (void) VSTREAM_GETC(stream); + return (err); +} + +/* deliver_request_get - receive message delivery request */ + +static int deliver_request_get(VSTREAM *stream, DELIVER_REQUEST *request) +{ + const char *myname = "deliver_request_get"; + const char *path; + struct stat st; + static VSTRING *queue_name; + static VSTRING *queue_id; + static VSTRING *nexthop; + static VSTRING *encoding; + static VSTRING *address; + static VSTRING *client_name; + static VSTRING *client_addr; + static VSTRING *client_port; + static VSTRING *client_proto; + static VSTRING *client_helo; + static VSTRING *sasl_method; + static VSTRING *sasl_username; + static VSTRING *sasl_sender; + static VSTRING *log_ident; + static VSTRING *rewrite_context; + static VSTRING *dsn_envid; + static RCPT_BUF *rcpt_buf; + int rcpt_count; + int smtputf8; + int dsn_ret; + + /* + * Initialize. For some reason I wanted to allow for multiple instances + * of a deliver_request structure, thus the hoopla with string + * initialization and copying. + */ + if (queue_name == 0) { + queue_name = vstring_alloc(10); + queue_id = vstring_alloc(10); + nexthop = vstring_alloc(10); + encoding = vstring_alloc(10); + address = vstring_alloc(10); + client_name = vstring_alloc(10); + client_addr = vstring_alloc(10); + client_port = vstring_alloc(10); + client_proto = vstring_alloc(10); + client_helo = vstring_alloc(10); + sasl_method = vstring_alloc(10); + sasl_username = vstring_alloc(10); + sasl_sender = vstring_alloc(10); + log_ident = vstring_alloc(10); + rewrite_context = vstring_alloc(10); + dsn_envid = vstring_alloc(10); + rcpt_buf = rcpb_create(); + } + + /* + * Extract the queue file name, data offset, and sender address. Abort + * the conversation when they send bad information. + */ + if (attr_scan(stream, ATTR_FLAG_STRICT, + RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request->flags), + RECV_ATTR_STR(MAIL_ATTR_QUEUE, queue_name), + RECV_ATTR_STR(MAIL_ATTR_QUEUEID, queue_id), + RECV_ATTR_LONG(MAIL_ATTR_OFFSET, &request->data_offset), + RECV_ATTR_LONG(MAIL_ATTR_SIZE, &request->data_size), + RECV_ATTR_STR(MAIL_ATTR_NEXTHOP, nexthop), + RECV_ATTR_STR(MAIL_ATTR_ENCODING, encoding), + RECV_ATTR_INT(MAIL_ATTR_SMTPUTF8, &smtputf8), + RECV_ATTR_STR(MAIL_ATTR_SENDER, address), + RECV_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid), + RECV_ATTR_INT(MAIL_ATTR_DSN_RET, &dsn_ret), + RECV_ATTR_FUNC(msg_stats_scan, (void *) &request->msg_stats), + /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */ + RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_NAME, client_name), + RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_ADDR, client_addr), + RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_PORT, client_port), + RECV_ATTR_STR(MAIL_ATTR_LOG_PROTO_NAME, client_proto), + RECV_ATTR_STR(MAIL_ATTR_LOG_HELO_NAME, client_helo), + /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */ + RECV_ATTR_STR(MAIL_ATTR_SASL_METHOD, sasl_method), + RECV_ATTR_STR(MAIL_ATTR_SASL_USERNAME, sasl_username), + RECV_ATTR_STR(MAIL_ATTR_SASL_SENDER, sasl_sender), + /* XXX Ditto if we want to pass TLS certificate info. */ + RECV_ATTR_STR(MAIL_ATTR_LOG_IDENT, log_ident), + RECV_ATTR_STR(MAIL_ATTR_RWR_CONTEXT, rewrite_context), + RECV_ATTR_INT(MAIL_ATTR_RCPT_COUNT, &rcpt_count), + ATTR_TYPE_END) != 23) { + msg_warn("%s: error receiving common attributes", myname); + return (-1); + } + if (mail_open_ok(vstring_str(queue_name), + vstring_str(queue_id), &st, &path) == 0) + return (-1); + + /* Don't override hand-off time after deliver_pass() delegation. */ + if (request->msg_stats.agent_handoff.tv_sec == 0) + GETTIMEOFDAY(&request->msg_stats.agent_handoff); + + request->queue_name = mystrdup(vstring_str(queue_name)); + request->queue_id = mystrdup(vstring_str(queue_id)); + request->nexthop = mystrdup(vstring_str(nexthop)); + request->encoding = mystrdup(vstring_str(encoding)); + /* Fix 20140708: dedicated smtputf8 attribute with its own flags. */ + request->smtputf8 = smtputf8; + request->sender = mystrdup(vstring_str(address)); + request->client_name = mystrdup(vstring_str(client_name)); + request->client_addr = mystrdup(vstring_str(client_addr)); + request->client_port = mystrdup(vstring_str(client_port)); + request->client_proto = mystrdup(vstring_str(client_proto)); + request->client_helo = mystrdup(vstring_str(client_helo)); + request->sasl_method = mystrdup(vstring_str(sasl_method)); + request->sasl_username = mystrdup(vstring_str(sasl_username)); + request->sasl_sender = mystrdup(vstring_str(sasl_sender)); + request->log_ident = mystrdup(vstring_str(log_ident)); + request->rewrite_context = mystrdup(vstring_str(rewrite_context)); + request->dsn_envid = mystrdup(vstring_str(dsn_envid)); + request->dsn_ret = dsn_ret; + + /* + * Extract the recipient offset and address list. Skip over any + * attributes from the sender that we do not understand. + */ + while (rcpt_count-- > 0) { + if (attr_scan(stream, ATTR_FLAG_STRICT, + RECV_ATTR_FUNC(rcpb_scan, (void *) rcpt_buf), + ATTR_TYPE_END) != 1) { + msg_warn("%s: error receiving recipient attributes", myname); + return (-1); + } + recipient_list_add(&request->rcpt_list, rcpt_buf->offset, + vstring_str(rcpt_buf->dsn_orcpt), + rcpt_buf->dsn_notify, + vstring_str(rcpt_buf->orig_addr), + vstring_str(rcpt_buf->address)); + } + if (request->rcpt_list.len <= 0) { + msg_warn("%s: no recipients in delivery request for destination %s", + request->queue_id, request->nexthop); + return (-1); + } + + /* + * Open the queue file and set a shared lock, in order to prevent + * duplicate deliveries when the queue is flushed immediately after queue + * manager restart. + * + * The queue manager locks the file exclusively when it enters the active + * queue, and releases the lock before starting deliveries from that + * file. The queue manager does not lock the file again when reading more + * recipients into memory. When the queue manager is restarted, the new + * process moves files from the active queue to the incoming queue to + * cool off for a while. Delivery agents should therefore never try to + * open a file that is locked by a queue manager process. + * + * Opening the queue file can fail for a variety of reasons, such as the + * system running out of resources. Instead of throwing away mail, we're + * raising a fatal error which forces the mail system to back off, and + * retry later. + */ +#define DELIVER_LOCK_MODE (MYFLOCK_OP_SHARED | MYFLOCK_OP_NOWAIT) + + request->fp = + mail_queue_open(request->queue_name, request->queue_id, O_RDWR, 0); + if (request->fp == 0) { + if (errno != ENOENT) + msg_fatal("open %s %s: %m", request->queue_name, request->queue_id); + msg_warn("open %s %s: %m", request->queue_name, request->queue_id); + return (-1); + } + if (msg_verbose) + msg_info("%s: file %s", myname, VSTREAM_PATH(request->fp)); + if (myflock(vstream_fileno(request->fp), INTERNAL_LOCK, DELIVER_LOCK_MODE) < 0) + msg_fatal("shared lock %s: %m", VSTREAM_PATH(request->fp)); + close_on_exec(vstream_fileno(request->fp), CLOSE_ON_EXEC); + + return (0); +} + +/* deliver_request_alloc - allocate delivery request structure */ + +static DELIVER_REQUEST *deliver_request_alloc(void) +{ + DELIVER_REQUEST *request; + + request = (DELIVER_REQUEST *) mymalloc(sizeof(*request)); + request->fp = 0; + request->queue_name = 0; + request->queue_id = 0; + request->nexthop = 0; + request->encoding = 0; + request->sender = 0; + request->data_offset = 0; + request->data_size = 0; + recipient_list_init(&request->rcpt_list, RCPT_LIST_INIT_STATUS); + request->hop_status = 0; + request->client_name = 0; + request->client_addr = 0; + request->client_port = 0; + request->client_proto = 0; + request->client_helo = 0; + request->sasl_method = 0; + request->sasl_username = 0; + request->sasl_sender = 0; + request->log_ident = 0; + request->rewrite_context = 0; + request->dsn_envid = 0; + return (request); +} + +/* deliver_request_free - clean up delivery request structure */ + +static void deliver_request_free(DELIVER_REQUEST *request) +{ + if (request->fp) + vstream_fclose(request->fp); + if (request->queue_name) + myfree(request->queue_name); + if (request->queue_id) + myfree(request->queue_id); + if (request->nexthop) + myfree(request->nexthop); + if (request->encoding) + myfree(request->encoding); + if (request->sender) + myfree(request->sender); + recipient_list_free(&request->rcpt_list); + if (request->hop_status) + dsn_free(request->hop_status); + if (request->client_name) + myfree(request->client_name); + if (request->client_addr) + myfree(request->client_addr); + if (request->client_port) + myfree(request->client_port); + if (request->client_proto) + myfree(request->client_proto); + if (request->client_helo) + myfree(request->client_helo); + if (request->sasl_method) + myfree(request->sasl_method); + if (request->sasl_username) + myfree(request->sasl_username); + if (request->sasl_sender) + myfree(request->sasl_sender); + if (request->log_ident) + myfree(request->log_ident); + if (request->rewrite_context) + myfree(request->rewrite_context); + if (request->dsn_envid) + myfree(request->dsn_envid); + myfree((void *) request); +} + +/* deliver_request_read - create and read delivery request */ + +DELIVER_REQUEST *deliver_request_read(VSTREAM *stream) +{ + DELIVER_REQUEST *request; + + /* + * Tell the queue manager that we are ready for this request. + */ + if (deliver_request_initial(stream) != 0) + return (0); + + /* + * Be prepared for the queue manager to change its mind after contacting + * us. This can happen when a transport or host goes bad. + */ + (void) read_wait(vstream_fileno(stream), -1); + if (peekfd(vstream_fileno(stream)) <= 0) + return (0); + + /* + * Allocate and read the queue manager's delivery request. + */ +#define XXX_DEFER_STATUS -1 + + request = deliver_request_alloc(); + if (deliver_request_get(stream, request) < 0) { + deliver_request_done(stream, request, XXX_DEFER_STATUS); + request = 0; + } + return (request); +} + +/* deliver_request_done - finish delivery request */ + +int deliver_request_done(VSTREAM *stream, DELIVER_REQUEST *request, int status) +{ + int err; + + err = deliver_request_final(stream, request, status); + deliver_request_free(request); + return (err); +} |