freebsd-dev/contrib/dma/mail.c
2021-09-22 11:10:58 +02:00

519 lines
11 KiB
C

/*
* Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
* Copyright (c) 2008 The DragonFly Project. All rights reserved.
*
* This code is derived from software contributed to The DragonFly Project
* by Simon Schubert <2@0x2c.org>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name of The DragonFly Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific, prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <inttypes.h>
#include <signal.h>
#include <strings.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "dma.h"
#define MAX_LINE_RFC822 1000
void
bounce(struct qitem *it, const char *reason)
{
struct queue bounceq;
char line[1000];
size_t pos;
int error;
/* Don't bounce bounced mails */
if (it->sender[0] == 0) {
syslog(LOG_INFO, "can not bounce a bounce message, discarding");
exit(EX_SOFTWARE);
}
bzero(&bounceq, sizeof(bounceq));
LIST_INIT(&bounceq.queue);
bounceq.sender = "";
if (add_recp(&bounceq, it->sender, EXPAND_WILDCARD) != 0)
goto fail;
if (newspoolf(&bounceq) != 0)
goto fail;
syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
setlogident("%s", bounceq.id);
error = fprintf(bounceq.mailf,
"Received: from MAILER-DAEMON\n"
"\tid %s\n"
"\tby %s (%s on %s);\n"
"\t%s\n"
"X-Original-To: <%s>\n"
"From: MAILER-DAEMON <>\n"
"To: %s\n"
"Subject: Mail delivery failed\n"
"Message-Id: <%s@%s>\n"
"Date: %s\n"
"\n"
"This is the %s at %s.\n"
"\n"
"There was an error delivering your mail to <%s>.\n"
"\n"
"%s\n"
"\n"
"%s\n"
"\n",
bounceq.id,
hostname(), VERSION, systemhostname(),
rfc822date(),
it->addr,
it->sender,
bounceq.id, hostname(),
rfc822date(),
VERSION, hostname(),
it->addr,
reason,
config.features & FULLBOUNCE ?
"Original message follows." :
"Message headers follow.");
if (error < 0)
goto fail;
if (fseek(it->mailf, 0, SEEK_SET) != 0)
goto fail;
if (config.features & FULLBOUNCE) {
while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
if (fwrite(line, 1, pos, bounceq.mailf) != pos)
goto fail;
}
} else {
while (!feof(it->mailf)) {
if (fgets(line, sizeof(line), it->mailf) == NULL)
break;
if (line[0] == '\n')
break;
if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
goto fail;
}
}
if (linkspool(&bounceq) != 0)
goto fail;
/* bounce is safe */
delqueue(it);
run_queue(&bounceq);
/* NOTREACHED */
fail:
syslog(LOG_CRIT, "error creating bounce: %m");
delqueue(it);
exit(EX_IOERR);
}
struct parse_state {
char addr[1000];
int pos;
enum {
NONE = 0,
START,
MAIN,
EOL,
QUIT
} state;
int comment;
int quote;
int brackets;
int esc;
};
/*
* Simplified RFC2822 header/address parsing.
* We copy escapes and quoted strings directly, since
* we have to pass them like this to the mail server anyways.
* XXX local addresses will need treatment
*/
static int
parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
{
char *addr;
again:
switch (ps->state) {
case NONE:
return (-1);
case START:
/* init our data */
bzero(ps, sizeof(*ps));
/* skip over header name */
while (*s != ':')
s++;
s++;
ps->state = MAIN;
break;
case MAIN:
/* all fine */
break;
case EOL:
switch (*s) {
case ' ':
case '\t':
ps->state = MAIN;
break;
default:
ps->state = QUIT;
if (ps->pos != 0)
goto newaddr;
return (0);
}
break;
case QUIT:
return (0);
}
for (; *s != 0; s++) {
if (ps->esc) {
ps->esc = 0;
switch (*s) {
case '\r':
case '\n':
goto err;
default:
goto copy;
}
}
if (ps->quote) {
switch (*s) {
case '"':
ps->quote = 0;
goto copy;
case '\\':
ps->esc = 1;
goto copy;
case '\r':
case '\n':
goto eol;
default:
goto copy;
}
}
switch (*s) {
case '(':
ps->comment++;
break;
case ')':
if (ps->comment)
ps->comment--;
else
goto err;
goto skip;
case '"':
ps->quote = 1;
goto copy;
case '\\':
ps->esc = 1;
goto copy;
case '\r':
case '\n':
goto eol;
}
if (ps->comment)
goto skip;
switch (*s) {
case ' ':
case '\t':
/* ignore whitespace */
goto skip;
case '<':
/* this is the real address now */
ps->brackets = 1;
ps->pos = 0;
goto skip;
case '>':
if (!ps->brackets)
goto err;
ps->brackets = 0;
s++;
goto newaddr;
case ':':
/* group - ignore */
ps->pos = 0;
goto skip;
case ',':
case ';':
/*
* Next address, copy previous one.
* However, we might be directly after
* a <address>, or have two consecutive
* commas.
* Skip the comma unless there is
* really something to copy.
*/
if (ps->pos == 0)
goto skip;
s++;
goto newaddr;
default:
goto copy;
}
copy:
if (ps->comment)
goto skip;
if (ps->pos + 1 == sizeof(ps->addr))
goto err;
ps->addr[ps->pos++] = *s;
skip:
;
}
eol:
ps->state = EOL;
return (0);
err:
ps->state = QUIT;
return (-1);
newaddr:
ps->addr[ps->pos] = 0;
ps->pos = 0;
addr = strdup(ps->addr);
if (addr == NULL)
errlog(EX_SOFTWARE, "strdup");
if (add_recp(queue, addr, EXPAND_WILDCARD) != 0)
errlogx(EX_DATAERR, "invalid recipient `%s'", addr);
goto again;
}
static int
writeline(struct queue *queue, const char *line, ssize_t linelen)
{
ssize_t len;
while (linelen > 0) {
len = linelen;
if (linelen > MAX_LINE_RFC822) {
len = MAX_LINE_RFC822 - 10;
}
if (fwrite(line, len, 1, queue->mailf) != 1)
return (-1);
if (linelen <= MAX_LINE_RFC822)
break;
if (fwrite("\n", 1, 1, queue->mailf) != 1)
return (-1);
line += MAX_LINE_RFC822 - 10;
linelen = strlen(line);
}
return (0);
}
int
readmail(struct queue *queue, int nodot, int recp_from_header)
{
struct parse_state parse_state;
char *line = NULL;
ssize_t linelen;
size_t linecap = 0;
char newline[MAX_LINE_RFC822];
size_t error;
int had_headers = 0;
int had_from = 0;
int had_messagid = 0;
int had_date = 0;
int had_first_line = 0;
int had_last_line = 0;
int nocopy = 0;
int ret = -1;
parse_state.state = NONE;
error = fprintf(queue->mailf,
"Received: from %s (uid %d)\n"
"\t(envelope-from %s)\n"
"\tid %s\n"
"\tby %s (%s on %s);\n"
"\t%s\n",
username, useruid,
queue->sender,
queue->id,
hostname(), VERSION, systemhostname(),
rfc822date());
if ((ssize_t)error < 0)
return (-1);
while (!feof(stdin)) {
newline[0] = '\0';
if ((linelen = getline(&line, &linecap, stdin)) <= 0)
break;
if (had_last_line)
errlogx(EX_DATAERR, "bad mail input format:"
" from %s (uid %d) (envelope-from %s)",
username, useruid, queue->sender);
linelen = strlen(line);
if (linelen == 0 || line[linelen - 1] != '\n') {
/*
* This line did not end with a newline character.
* If we fix it, it better be the last line of
* the file.
*/
line[linelen] = '\n';
line[linelen + 1] = 0;
had_last_line = 1;
}
if (!had_first_line) {
/*
* Ignore a leading RFC-976 From_ or >From_ line mistakenly
* inserted by some programs.
*/
if (strprefixcmp(line, "From ") == 0 || strprefixcmp(line, ">From ") == 0)
continue;
had_first_line = 1;
}
if (!had_headers) {
if (linelen > MAX_LINE_RFC822) {
/* XXX also split headers */
errlogx(EX_DATAERR, "bad mail input format:"
" from %s (uid %d) (envelope-from %s)",
username, useruid, queue->sender);
}
/*
* Unless this is a continuation, switch of
* the Bcc: nocopy flag.
*/
if (!(line[0] == ' ' || line[0] == '\t'))
nocopy = 0;
if (strprefixcmp(line, "Date:") == 0)
had_date = 1;
else if (strprefixcmp(line, "Message-Id:") == 0)
had_messagid = 1;
else if (strprefixcmp(line, "From:") == 0)
had_from = 1;
else if (strprefixcmp(line, "Bcc:") == 0)
nocopy = 1;
if (parse_state.state != NONE) {
if (parse_addrs(&parse_state, line, queue) < 0) {
errlogx(EX_DATAERR, "invalid address in header\n");
/* NOTREACHED */
}
}
if (recp_from_header && (
strprefixcmp(line, "To:") == 0 ||
strprefixcmp(line, "Cc:") == 0 ||
strprefixcmp(line, "Bcc:") == 0)) {
parse_state.state = START;
if (parse_addrs(&parse_state, line, queue) < 0) {
errlogx(EX_DATAERR, "invalid address in header\n");
/* NOTREACHED */
}
}
}
if (strcmp(line, "\n") == 0 && !had_headers) {
had_headers = 1;
while (!had_date || !had_messagid || !had_from) {
if (!had_date) {
had_date = 1;
snprintf(newline, sizeof(newline), "Date: %s\n", rfc822date());
} else if (!had_messagid) {
/* XXX msgid, assign earlier and log? */
had_messagid = 1;
snprintf(newline, sizeof(newline), "Message-Id: <%"PRIxMAX".%s.%"PRIxMAX"@%s>\n",
(uintmax_t)time(NULL),
queue->id,
(uintmax_t)random(),
hostname());
} else if (!had_from) {
had_from = 1;
snprintf(newline, sizeof(newline), "From: <%s>\n", queue->sender);
}
if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
goto fail;
}
strlcpy(newline, "\n", sizeof(newline));
}
if (!nodot && linelen == 2 && line[0] == '.')
break;
if (!nocopy) {
if (newline[0]) {
if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
goto fail;
} else {
if (writeline(queue, line, linelen) != 0)
goto fail;
}
}
}
ret = 0;
fail:
free(line);
return (ret);
}