OpenSolaris_b135/cmd/vscan/vscand/vs_svc.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Implementation of the "scan file" interface
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <syslog.h>
#include <sys/types.h>
#include <fcntl.h>
#include <bsm/adt.h>
#include <bsm/adt_event.h>
#include <pthread.h>
#include "vs_incl.h"
/*
* vs_svc_nodes - table of scan requests and their thread id and
* scan engine context.
* The table is sized by the value passed to vs_svc_init. This
* value is obtained from the kernel and represents the maximum
* request idx that the kernel will request vscand to process.
* The table is indexed by the vsr_idx value passed in
* the scan request - always non-zero. This value is also the index
* into the kernel scan request table and identifies the instance of
* the driver being used to access file data for the scan. Although
* this is of no consequence here, it is useful information for debug.
*
* When a scan request is received a response is sent indicating
* one of the following:
* VS_STATUS_ERROR - an error occurred
* VS_STATUS_NO_SCAN - no scan is required
* VS_STATUS_SCANNING - request has been queued for async processing
*
* If the scan is required (VS_STATUS_SCANNING) a thread is created
* to perform the scan. It's tid is saved in vs_svc_nodes.
*
* In the case of SHUTDOWN, vs_terminate requests that all scan
* engine connections be closed, thus termintaing any in-progress
* scans, then awaits completion of all scanning threads as identified
* in vs_svc_nodes.
*/
typedef struct vs_svc_node {
pthread_t vsn_tid;
vs_scan_req_t vsn_req;
vs_eng_ctx_t vsn_eng;
} vs_svc_node_t;
static vs_svc_node_t *vs_svc_nodes;
static uint32_t vs_svc_max_node; /* max idx into vs_svc_nodes */
static pthread_mutex_t vs_svc_mutex = PTHREAD_MUTEX_INITIALIZER;
/* local functions */
static void *vs_svc_async_scan(void *);
static int vs_svc_scan_file(vs_svc_node_t *, vs_scanstamp_t *);
static void vs_svc_vlog(char *, vs_result_t *);
static void vs_svc_audit(char *, vs_result_t *);
/*
* vs_svc_init, vs_svc_fini
*
* Invoked on daemon load and unload
*/
int
vs_svc_init(uint32_t max_req)
{
vs_svc_max_node = max_req;
vs_svc_nodes = (vs_svc_node_t *)
calloc(max_req + 1, sizeof (vs_svc_node_t));
return (vs_svc_nodes == NULL ? -1 : 0);
}
void
vs_svc_fini()
{
if (vs_svc_nodes)
free(vs_svc_nodes);
}
/*
* vs_svc_terminate
*
* Close all scan engine connections to terminate in-progress scan
* requests, and wait for all threads in vs_svc_nodes to complete
*/
void
vs_svc_terminate()
{
int i;
pthread_t tid;
/* close connections to abort requests */
vs_eng_close_connections();
/* wait for threads */
for (i = 1; i <= vs_svc_max_node; i++) {
(void) pthread_mutex_lock(&vs_svc_mutex);
tid = vs_svc_nodes[i].vsn_tid;
(void) pthread_mutex_unlock(&vs_svc_mutex);
if (tid != 0)
(void) pthread_join(tid, NULL);
}
}
/*
* vs_svc_queue_scan_req
*
* Determine if the file needs to be scanned - either it has
* been modified or its scanstamp is not current.
* Initiate a thread to process the request, saving the tid
* in vs_svc_nodes[idx].vsn_tid, where idx is the vsr_idx passed in
* the scan request.
*
* Returns: VS_STATUS_ERROR - error
* VS_STATUS_NO_SCAN - no scan required
* VS_STATUS_SCANNING - async scan initiated
*/
int
vs_svc_queue_scan_req(vs_scan_req_t *req)
{
pthread_t tid;
vs_svc_node_t *node;
/* No scan if file quarantined */
if (req->vsr_quarantined)
return (VS_STATUS_NO_SCAN);
/* No scan if file not modified AND scanstamp is current */
if ((req->vsr_modified == 0) &&
vs_eng_scanstamp_current(req->vsr_scanstamp)) {
return (VS_STATUS_NO_SCAN);
}
/* scan required */
node = &(vs_svc_nodes[req->vsr_idx]);
(void) pthread_mutex_lock(&vs_svc_mutex);
if ((node->vsn_tid != 0) || (req->vsr_idx > vs_svc_max_node)) {
(void) pthread_mutex_unlock(&vs_svc_mutex);
return (VS_STATUS_ERROR);
}
node->vsn_req = *req;
if (pthread_create(&tid, NULL, vs_svc_async_scan, (void *)node) != 0) {
(void) pthread_mutex_unlock(&vs_svc_mutex);
return (VS_STATUS_ERROR);
}
node->vsn_tid = tid;
(void) pthread_mutex_unlock(&vs_svc_mutex);
return (VS_STATUS_SCANNING);
}
/*
* vs_svc_async_scan
*
* Initialize response structure, invoke vs_svc_scan_file to
* perform the scan, then send the result to the kernel.
*/
static void *
vs_svc_async_scan(void *arg)
{
vs_svc_node_t *node = (vs_svc_node_t *)arg;
vs_scan_req_t *scan_req = &(node->vsn_req);
vs_scan_rsp_t scan_rsp;
scan_rsp.vsr_idx = scan_req->vsr_idx;
scan_rsp.vsr_seqnum = scan_req->vsr_seqnum;
scan_rsp.vsr_result = vs_svc_scan_file(node, &scan_rsp.vsr_scanstamp);
/* clear node and send async response to kernel */
(void) pthread_mutex_lock(&vs_svc_mutex);
(void) memset(node, 0, sizeof (vs_svc_node_t));
(void) pthread_mutex_unlock(&vs_svc_mutex);
(void) vscand_kernel_result(&scan_rsp);
return (NULL);
}
/*
* vs_svc_scan_file
*
* vs_svc_scan_file is responsible for:
* - obtaining & releasing a scan engine connection
* - invoking the scan engine interface code to do the scan
* - retrying a failed scan (up to VS_MAX_RETRY times)
* - updating scan statistics
* - logging virus information
*
*
* Returns:
* VS_STATUS_NO_SCAN - scan not reqd; daemon shutting down
* VS_STATUS_CLEAN - scan success. File clean.
* new scanstamp returned in scanstamp param.
* VS_STATUS_INFECTED - scan success. File infected.
* VS_STATUS_ERROR - scan failure either in vscand or scan engine.
*/
static int
vs_svc_scan_file(vs_svc_node_t *node, vs_scanstamp_t *scanstamp)
{
char devname[MAXPATHLEN];
int flags = 0;
int retries;
vs_result_t result;
vs_scan_req_t *req = &(node->vsn_req);
vs_eng_ctx_t *eng = &(node->vsn_eng);
(void) snprintf(devname, MAXPATHLEN, "%s%d", VS_DRV_PATH, req->vsr_idx);
/* initialize response scanstamp to current scanstamp value */
(void) strlcpy(*scanstamp, req->vsr_scanstamp, sizeof (vs_scanstamp_t));
(void) memset(&result, 0, sizeof (vs_result_t));
result.vsr_rc = VS_RESULT_UNDEFINED;
for (retries = 0; retries <= VS_MAX_RETRY; retries++) {
/* get engine connection */
if (vs_eng_get(eng, (retries != 0)) != 0) {
result.vsr_rc = VS_RESULT_ERROR;
continue;
}
/* shutdown could occur while waiting for engine connection */
if (vscand_get_state() == VS_STATE_SHUTDOWN) {
vs_eng_release(eng);
return (VS_STATUS_NO_SCAN);
}
/* scan file */
(void) vs_icap_scan_file(eng, devname, req->vsr_path,
req->vsr_size, flags, &result);
/* if no error, clear error state on engine and break */
if ((result.vsr_rc != VS_RESULT_SE_ERROR) &&
(result.vsr_rc != VS_RESULT_ERROR)) {
vs_eng_set_error(eng, 0);
vs_eng_release(eng);
break;
}
/* treat error on shutdown as scan not required */
if (vscand_get_state() == VS_STATE_SHUTDOWN) {
vs_eng_release(eng);
return (VS_STATUS_NO_SCAN);
}
/* set engine's error state and update engine stats */
if (result.vsr_rc == VS_RESULT_SE_ERROR)
vs_eng_set_error(eng, 1);
vs_eng_release(eng);
}
vs_stats_set(result.vsr_rc);
/*
* VS_RESULT_CLEANED - file infected, cleaned data available
* VS_RESULT_FORBIDDEN - file infected, no cleaned data
* Log virus, write audit record and return INFECTED status
*/
if (result.vsr_rc == VS_RESULT_CLEANED ||
result.vsr_rc == VS_RESULT_FORBIDDEN) {
vs_svc_vlog(req->vsr_path, &result);
vs_svc_audit(req->vsr_path, &result);
return (VS_STATUS_INFECTED);
}
/* VS_RESULT_CLEAN - Set the scanstamp and return CLEAN status */
if (result.vsr_rc == VS_RESULT_CLEAN) {
(void) strlcpy(*scanstamp, result.vsr_scanstamp,
sizeof (vs_scanstamp_t));
return (VS_STATUS_CLEAN);
}
return (VS_STATUS_ERROR);
}
/*
* vs_svc_vlog
*
* log details of infections detected in syslig
* If virus log is configured log details there too
*/
static void
vs_svc_vlog(char *filepath, vs_result_t *result)
{
FILE *fp = NULL;
time_t sec;
struct tm *timestamp;
char timebuf[18]; /* MM/DD/YY hh:mm:ss */
int i;
char *log;
/* syslog */
if (result->vsr_nviolations == 0) {
syslog(LOG_NOTICE, "quarantine %s\n", filepath);
} else {
for (i = 0; i < result->vsr_nviolations; i++) {
syslog(LOG_NOTICE, "quarantine %s %d - %s\n",
filepath,
result->vsr_vrec[i].vr_id,
result->vsr_vrec[i].vr_desc);
}
}
/* log file */
if (((log = vscand_viruslog()) == NULL) ||
((fp = fopen(log, "a")) == NULL)) {
return;
}
(void) time(&sec);
timestamp = localtime(&sec);
(void) strftime(timebuf, sizeof (timebuf), "%D %T", timestamp);
if (result->vsr_nviolations == 0) {
(void) fprintf(fp, "%s quarantine %d[%s]\n",
timebuf, strlen(filepath), filepath);
} else {
for (i = 0; i < result->vsr_nviolations; i++) {
(void) fprintf(fp, "%s quarantine %d[%s] %d - %d[%s]\n",
timebuf, strlen(filepath), filepath,
result->vsr_vrec[i].vr_id,
strlen(result->vsr_vrec[i].vr_desc),
result->vsr_vrec[i].vr_desc);
}
}
(void) fclose(fp);
}
/*
* vs_svc_audit
*
* Generate AUE_vscan_quarantine audit record containing name
* of infected file, and violation details if available.
*/
static void
vs_svc_audit(char *filepath, vs_result_t *result)
{
int i;
char *violations[VS_MAX_VIOLATIONS];
char data[VS_MAX_VIOLATIONS][VS_DESCRIPTION_MAX];
adt_session_data_t *ah;
adt_termid_t *p_tid;
adt_event_data_t *event;
if (adt_start_session(&ah, NULL, ADT_USE_PROC_DATA)) {
syslog(LOG_AUTH | LOG_ALERT, "adt_start_session: %m");
return;
}
if (adt_load_ttyname("/dev/console", &p_tid) != 0) {
syslog(LOG_AUTH | LOG_ALERT,
"adt_load_ttyname(/dev/console): %m");
return;
}
if (adt_set_user(ah, ADT_NO_ATTRIB, ADT_NO_ATTRIB, ADT_NO_ATTRIB,
ADT_NO_ATTRIB, p_tid, ADT_NEW) != 0) {
syslog(LOG_AUTH | LOG_ALERT, "adt_set_user(ADT_NO_ATTRIB): %m");
(void) adt_end_session(ah);
return;
}
if ((event = adt_alloc_event(ah, ADT_vscan_quarantine)) == NULL) {
syslog(LOG_AUTH | LOG_ALERT,
"adt_alloc_event(ADT_vscan_quarantine)): %m");
(void) adt_end_session(ah);
return;
}
/* populate vscan audit event */
event->adt_vscan_quarantine.file = filepath;
for (i = 0; i < result->vsr_nviolations; i++) {
(void) snprintf(data[i], VS_DESCRIPTION_MAX, "%d - %s",
result->vsr_vrec[i].vr_id, result->vsr_vrec[i].vr_desc);
violations[i] = data[i];
}
event->adt_vscan_quarantine.violations = (char **)violations;
event->adt_vscan_quarantine.nviolations = result->vsr_nviolations;
if (adt_put_event(event, ADT_SUCCESS, ADT_SUCCESS))
syslog(LOG_AUTH | LOG_ALERT, "adt_put_event: %m");
adt_free_event(event);
(void) adt_end_session(ah);
}