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/*
* dspam backend for dovecot antispam plugin
*
* Copyright (C) 2004-2007 Johannes Berg <johannes@sipsolutions.net>
* 2006 Frank Cusack
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License Version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <fcntl.h>
#include "lib.h"
#include "mail-storage-private.h"
#include "antispam-plugin.h"
#include "signature.h"
static const char *dspam_binary = "/usr/bin/dspam";
static char **extra_args = NULL;
static int extra_args_num = 0;
#define FIXED_ARGS_NUM 5
static int call_dspam(const char *signature, enum classification wanted)
{
pid_t pid;
const char *class_arg;
const char *sign_arg;
int pipes[2];
sign_arg = t_strconcat("--signature=", signature, NULL);
switch (wanted) {
case CLASS_NOTSPAM:
class_arg = t_strconcat("--class=", "innocent", NULL);
break;
case CLASS_SPAM:
class_arg = t_strconcat("--class=", "spam", NULL);
break;
}
/*
* For dspam stderr; dspam seems to not always exit with a
* non-zero exit code on errors so we treat it as an error
* if it logged anything to stderr.
*/
pipe(pipes);
pid = fork();
if (pid < 0)
return -1;
if (pid) {
int status;
char buf[1024];
int readsize;
bool error = FALSE;
close(pipes[1]);
do {
readsize = read(pipes[0], buf, sizeof(buf));
if (readsize < 0) {
readsize = -1;
if (errno == EINTR)
readsize = -2;
}
/*
* readsize > 0 means that we read a message from
* dspam, -1 means we failed to read for some odd
* reason
*/
if (readsize > 0 || readsize == -1)
error = TRUE;
} while (readsize == -2 || readsize > 0);
/*
* Wait for dspam, should return instantly since we've
* already waited above (waiting for stderr to close)
*/
waitpid(pid, &status, 0);
if (!WIFEXITED(status))
error = TRUE;
close(pipes[0]);
if (error)
return 1;
return WEXITSTATUS(status);
} else {
int fd = open("/dev/null", O_RDONLY);
char **argv;
int sz = sizeof(char *) * (FIXED_ARGS_NUM + extra_args_num);
int i;
argv = i_malloc(sz);
memset(argv, 0, sz);
close(0);
close(1);
close(2);
/* see above */
close(pipes[0]);
if (dup2(pipes[1], 2) != 2)
exit(1);
if (dup2(pipes[1], 1) != 1)
exit(1);
close(pipes[1]);
if (dup2(fd, 0) != 0)
exit(1);
close(fd);
argv[0] = (char *)dspam_binary;
argv[1] = "--source=error";
argv[2] = (char *)class_arg;
argv[3] = (char *)sign_arg;
#ifdef DEBUG_SYSLOG
/*
* not good with stderr debuggin since we then write to
* stderr which our parent takes as a bug
*/
debug("%s --source=error %s %s ...",
dspam_binary, class_arg, sign_arg);
#endif
for (i = 0; i < extra_args_num; i++)
argv[i + 4] = (char *)extra_args[i];
execv(dspam_binary, argv);
/* fall through if dspam can't be found */
exit(127);
/* not reached */
return -1;
}
}
struct antispam_transaction_context {
struct siglist *siglist;
};
struct antispam_transaction_context *
backend_start(struct mailbox *box __attr_unused__)
{
struct antispam_transaction_context *ast;
ast = i_new(struct antispam_transaction_context, 1);
ast->siglist = NULL;
return ast;
}
void backend_rollback(struct antispam_transaction_context *ast)
{
signature_list_free(&ast->siglist);
i_free(ast);
}
int backend_commit(struct mailbox_transaction_context *ctx,
struct antispam_transaction_context *ast)
{
struct siglist *item = ast->siglist;
int ret = 0;
while (item) {
if (call_dspam(item->sig, item->wanted)) {
ret = -1;
mail_storage_set_error(ctx->box->storage,
"Failed to call dspam");
break;
}
item = item->next;
}
signature_list_free(&ast->siglist);
i_free(ast);
return ret;
}
int backend_handle_mail(struct mailbox_transaction_context *t,
struct antispam_transaction_context *ast,
struct mail *mail, enum classification want)
{
return signature_extract_to_list(t, mail, &ast->siglist, want);
}
void backend_init(pool_t pool)
{
const char *tmp;
int i;
tmp = get_setting("DSPAM_BINARY");
if (tmp)
dspam_binary = tmp;
debug("dspam binary set to %s\n", dspam_binary);
tmp = get_setting("DSPAM_ARGS");
if (tmp) {
extra_args = p_strsplit(pool, tmp, ";");
extra_args_num = str_array_length(
(const char *const *)extra_args);
for (i = 0; i < extra_args_num; i++)
debug("dspam extra arg %s\n",
extra_args[i]);
}
signature_init();
}
void backend_exit(void)
{
}
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