ClamAV is an open source (GPLv2) anti-virus toolkit.
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clamav/clamdscan/proto.c

719 lines
20 KiB

/*
* Copyright (C) 2013-2020 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2009-2013 Sourcefire, Inc.
*
* Authors: Tomasz Kojm, aCaB
*
* 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.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#if defined(C_SOLARIS)
#ifndef __EXTENSIONS__
#define __EXTENSIONS__
#endif
#endif
/* must be first because it may define _XOPEN_SOURCE */
#include "shared/fdpassing.h"
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#ifndef _WIN32
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netdb.h>
#endif
#include "libclamav/clamav.h"
#include "libclamav/others.h"
#include "shared/actions.h"
#include "shared/output.h"
#include "shared/misc.h"
#include "shared/clamdcom.h"
#include "proto.h"
#include "client.h"
extern unsigned long int maxstream;
int printinfected;
extern struct optstruct *clamdopts;
#ifndef _WIN32
extern struct sockaddr_un nixsock;
#endif
static const char *scancmd[] = {"CONTSCAN", "MULTISCAN", "INSTREAM", "FILDES", "ALLMATCHSCAN"};
/* Connects to clamd
* Returns a FD or -1 on error */
int dconnect()
{
int sockd, res;
const struct optstruct *opt;
struct addrinfo hints, *info, *p;
char port[10];
char *ipaddr;
#ifndef _WIN32
opt = optget(clamdopts, "LocalSocket");
if (opt->enabled) {
if ((sockd = socket(AF_UNIX, SOCK_STREAM, 0)) >= 0) {
if (connect(sockd, (struct sockaddr *)&nixsock, sizeof(nixsock)) == 0)
return sockd;
else {
logg("!Could not connect to clamd on LocalSocket %s: %s\n", opt->strarg, strerror(errno));
close(sockd);
}
}
}
#endif
snprintf(port, sizeof(port), "%lld", optget(clamdopts, "TCPSocket")->numarg);
opt = optget(clamdopts, "TCPAddr");
while (opt) {
if (opt->enabled) {
ipaddr = NULL;
if (opt->strarg)
ipaddr = (!strcmp(opt->strarg, "any") ? NULL : opt->strarg);
memset(&hints, 0x00, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if ((res = getaddrinfo(ipaddr, port, &hints, &info))) {
logg("!Could not lookup %s: %s\n", ipaddr ? ipaddr : "", gai_strerror(res));
opt = opt->nextarg;
continue;
}
for (p = info; p != NULL; p = p->ai_next) {
if ((sockd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0) {
logg("!Can't create the socket: %s\n", strerror(errno));
continue;
}
if (connect(sockd, p->ai_addr, p->ai_addrlen) < 0) {
logg("!Could not connect to clamd on %s: %s\n", opt->strarg, strerror(errno));
closesocket(sockd);
continue;
}
freeaddrinfo(info);
return sockd;
}
freeaddrinfo(info);
}
opt = opt->nextarg;
}
return -1;
}
/* Issues an INSTREAM command to clamd and streams the given file
* Returns >0 on success, 0 soft fail, -1 hard fail */
static int send_stream(int sockd, const char *filename)
{
uint32_t buf[BUFSIZ / sizeof(uint32_t)];
int fd, len;
unsigned long int todo = maxstream;
if (filename) {
if ((fd = safe_open(filename, O_RDONLY | O_BINARY)) < 0) {
logg("~%s: Access denied. ERROR\n", filename);
return 0;
}
} else
fd = 0;
if (sendln(sockd, "zINSTREAM", 10)) {
close(fd);
return -1;
}
while ((len = read(fd, &buf[1], sizeof(buf) - sizeof(uint32_t))) > 0) {
if ((unsigned int)len > todo) len = todo;
buf[0] = htonl(len);
if (sendln(sockd, (const char *)buf, len + sizeof(uint32_t))) {
close(fd);
return -1;
}
todo -= len;
if (!todo) {
len = 0;
break;
}
}
close(fd);
if (len) {
logg("!Failed to read from %s.\n", filename ? filename : "STDIN");
return 0;
}
*buf = 0;
sendln(sockd, (const char *)buf, 4);
return 1;
}
#ifdef HAVE_FD_PASSING
/* Issues a FILDES command and pass a FD to clamd
* Returns >0 on success, 0 soft fail, -1 hard fail */
static int send_fdpass(int sockd, const char *filename)
{
struct iovec iov[1];
struct msghdr msg;
struct cmsghdr *cmsg;
unsigned char fdbuf[CMSG_SPACE(sizeof(int))];
char dummy[] = "";
int fd;
if (filename) {
if ((fd = open(filename, O_RDONLY)) < 0) {
logg("~%s: Access denied. ERROR\n", filename);
return 0;
}
} else
fd = 0;
if (sendln(sockd, "zFILDES", 8)) {
close(fd);
return -1;
}
iov[0].iov_base = dummy;
iov[0].iov_len = 1;
memset(&msg, 0, sizeof(msg));
msg.msg_control = fdbuf;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
msg.msg_controllen = CMSG_LEN(sizeof(int));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = fd;
if (sendmsg(sockd, &msg, 0) == -1) {
logg("!FD send failed: %s\n", strerror(errno));
close(fd);
return -1;
}
close(fd);
return 1;
}
#endif
/* 0: scan, 1: skip */
static int chkpath(const char *path)
{
const struct optstruct *opt;
if ((opt = optget(clamdopts, "ExcludePath"))->enabled) {
while (opt) {
if (match_regex(path, opt->strarg) == 1) {
if (printinfected != 1)
logg("~%s: Excluded\n", path);
return 1;
}
opt = opt->nextarg;
}
}
return 0;
}
static int ftw_chkpath(const char *path, struct cli_ftw_cbdata *data)
{
UNUSEDPARAM(data);
return chkpath(path);
}
/* Sends a proper scan request to clamd and parses its replies
* This is used only in non IDSESSION mode
* Returns the number of infected files or -1 on error
* NOTE: filename may be NULL for STREAM scantype. */
int dsresult(int sockd, int scantype, const char *filename, int *printok, int *errors)
{
int infected = 0, len = 0, beenthere = 0;
char *bol, *eol;
struct RCVLN rcv;
STATBUF sb;
if (filename) {
if (1 == chkpath(filename)) {
goto done;
}
}
recvlninit(&rcv, sockd);
switch (scantype) {
case MULTI:
case CONT:
case ALLMATCH:
if (!filename) {
logg("Filename cannot be NULL for MULTISCAN or CONTSCAN.\n");
infected = -1;
goto done;
}
len = strlen(filename) + strlen(scancmd[scantype]) + 3;
if (!(bol = malloc(len))) {
logg("!Cannot allocate a command buffer: %s\n", strerror(errno));
infected = -1;
goto done;
}
sprintf(bol, "z%s %s", scancmd[scantype], filename);
if (sendln(sockd, bol, len)) {
free(bol);
infected = -1;
goto done;
}
free(bol);
break;
case STREAM:
/* NULL filename safe in send_stream() */
len = send_stream(sockd, filename);
break;
#ifdef HAVE_FD_PASSING
case FILDES:
/* NULL filename safe in send_fdpass() */
len = send_fdpass(sockd, filename);
break;
#endif
}
if (len <= 0) {
*printok = 0;
if (errors)
(*errors)++;
infected = len;
goto done;
}
while ((len = recvln(&rcv, &bol, &eol))) {
if (len == -1) {
infected = -1;
goto done;
}
beenthere = 1;
if (!filename) logg("~%s\n", bol);
if (len > 7) {
char *colon = strrchr(bol, ':');
if (colon && colon[1] != ' ') {
char *br;
*colon = 0;
br = strrchr(bol, '(');
if (br)
*br = 0;
colon = strrchr(bol, ':');
}
if (!colon) {
char *unkco = "UNKNOWN COMMAND";
if (!strncmp(bol, unkco, sizeof(unkco) - 1))
logg("clamd replied \"UNKNOWN COMMAND\". Command was %s\n",
(scantype < 0 || scantype > MAX_SCANTYPE) ? "unidentified" : scancmd[scantype]);
else
logg("Failed to parse reply: \"%s\"\n", bol);
infected = -1;
goto done;
} else if (!memcmp(eol - 7, " FOUND", 6)) {
static char last_filename[PATH_MAX + 1] = {'\0'};
*(eol - 7) = 0;
*printok = 0;
if (scantype != ALLMATCH) {
infected++;
} else {
if (filename != NULL && strcmp(filename, last_filename)) {
infected++;
strncpy(last_filename, filename, PATH_MAX);
last_filename[PATH_MAX] = '\0';
}
}
if (filename) {
if (scantype >= STREAM) {
logg("~%s%s FOUND\n", filename, colon);
if (action) action(filename);
} else {
logg("~%s FOUND\n", bol);
*colon = '\0';
if (action)
action(bol);
}
}
} else if (!memcmp(eol - 7, " ERROR", 6)) {
if (errors)
(*errors)++;
*printok = 0;
if (filename) {
if (scantype >= STREAM)
logg("~%s%s\n", filename, colon);
else
logg("~%s\n", bol);
}
}
}
}
if (!beenthere) {
if (!filename) {
logg("STDIN: noreply from clamd\n.");
infected = -1;
goto done;
}
if (CLAMSTAT(filename, &sb) == -1) {
logg("~%s: stat() failed with %s, clamd may not be responding\n",
filename, strerror(errno));
infected = -1;
goto done;
}
if (!S_ISDIR(sb.st_mode)) {
logg("~%s: no reply from clamd\n", filename);
infected = -1;
goto done;
}
}
done:
return infected;
}
/* Used by serial_callback() */
struct client_serial_data {
int infected;
int scantype;
int printok;
int files;
int errors;
};
/* FTW callback for scanning in non IDSESSION mode
* Returns SUCCESS or BREAK on success, CL_EXXX on error */
static int serial_callback(STATBUF *sb, char *filename, const char *path, enum cli_ftw_reason reason, struct cli_ftw_cbdata *data)
{
struct client_serial_data *c = (struct client_serial_data *)data->data;
int sockd, ret;
const char *f = filename;
UNUSEDPARAM(sb);
if (chkpath(path))
return CL_SUCCESS;
c->files++;
switch (reason) {
case error_stat:
logg("!Can't access file %s\n", path);
c->errors++;
return CL_SUCCESS;
case error_mem:
logg("!Memory allocation failed in ftw\n");
c->errors++;
return CL_EMEM;
case warning_skipped_dir:
logg("^Directory recursion limit reached\n");
case warning_skipped_link:
return CL_SUCCESS;
case warning_skipped_special:
logg("^%s: Not supported file type\n", path);
c->errors++;
return CL_SUCCESS;
case visit_directory_toplev:
if (c->scantype >= STREAM)
return CL_SUCCESS;
f = path;
filename = NULL;
case visit_file:
break;
}
if ((sockd = dconnect()) < 0) {
if (filename) free(filename);
c->errors++;
return CL_EOPEN;
}
ret = dsresult(sockd, c->scantype, f, &c->printok, &c->errors);
if (filename) free(filename);
closesocket(sockd);
if (ret < 0) {
c->errors++;
return CL_EOPEN;
}
c->infected += ret;
if (reason == visit_directory_toplev)
return CL_BREAK;
return CL_SUCCESS;
}
/* Non-IDSESSION handler
* Returns non zero for serious errors, zero otherwise */
int serial_client_scan(char *file, int scantype, int *infected, int *err, int maxlevel, int flags)
{
struct cli_ftw_cbdata data;
struct client_serial_data cdata;
int ftw;
cdata.infected = 0;
cdata.files = 0;
cdata.errors = 0;
cdata.printok = printinfected ^ 1;
cdata.scantype = scantype;
data.data = &cdata;
ftw = cli_ftw(file, flags, maxlevel ? maxlevel : INT_MAX, serial_callback, &data, ftw_chkpath);
*infected += cdata.infected;
*err += cdata.errors;
if (!cdata.errors && (ftw == CL_SUCCESS || ftw == CL_BREAK)) {
if (cdata.printok)
logg("~%s: OK\n", file);
return 0;
} else if (!cdata.files) {
logg("~%s: No files scanned\n", file);
return 0;
}
return 1;
}
/* Used in IDSESSION mode */
struct client_parallel_data {
int infected;
int files;
int errors;
int scantype;
int sockd;
int lastid;
int printok;
struct SCANID {
unsigned int id;
const char *file;
struct SCANID *next;
} * ids;
};
/* Sends a proper scan request to clamd and parses its replies
* This is used only in IDSESSION mode
* Returns 0 on success, 1 on hard failures, 2 on len == 0 (bb#1717) */
static int dspresult(struct client_parallel_data *c)
{
const char *filename;
char *bol, *eol;
unsigned int rid;
int len;
struct SCANID **id = NULL;
struct RCVLN rcv;
recvlninit(&rcv, c->sockd);
do {
len = recvln(&rcv, &bol, &eol);
if (len < 0) return 1;
if (!len) return 2;
if ((rid = atoi(bol))) {
id = &c->ids;
while (*id) {
if ((*id)->id == rid) break;
id = &((*id)->next);
}
if (!*id) id = NULL;
}
if (!id) {
logg("!Bogus session id from clamd\n");
return 1;
}
filename = (*id)->file;
if (len > 7) {
char *colon = strrchr(bol, ':');
if (!colon) {
logg("!Failed to parse reply\n");
free((void *)filename);
return 1;
} else if (!memcmp(eol - 7, " FOUND", 6)) {
c->infected++;
c->printok = 0;
logg("~%s%s\n", filename, colon);
if (action) action(filename);
} else if (!memcmp(eol - 7, " ERROR", 6)) {
c->errors++;
c->printok = 0;
logg("~%s%s\n", filename, colon);
}
}
free((void *)filename);
bol = (char *)*id;
*id = (*id)->next;
free(bol);
} while (rcv.cur != rcv.buf); /* clamd sends whole lines, so, on partial lines, we just assume
more data can be recv()'d with close to zero latency */
return 0;
}
/* FTW callback for scanning in IDSESSION mode
* Returns SUCCESS on success, CL_EXXX or BREAK on error */
static int parallel_callback(STATBUF *sb, char *filename, const char *path, enum cli_ftw_reason reason, struct cli_ftw_cbdata *data)
{
struct client_parallel_data *c = (struct client_parallel_data *)data->data;
struct SCANID *cid;
int res = CL_CLEAN;
UNUSEDPARAM(sb);
if (chkpath(path))
return CL_SUCCESS;
c->files++;
switch (reason) {
case error_stat:
logg("!Can't access file %s\n", path);
c->errors++;
return CL_SUCCESS;
case error_mem:
logg("!Memory allocation failed in ftw\n");
c->errors++;
return CL_EMEM;
case warning_skipped_dir:
logg("^Directory recursion limit reached\n");
return CL_SUCCESS;
case warning_skipped_special:
logg("^%s: Not supported file type\n", path);
c->errors++;
case warning_skipped_link:
case visit_directory_toplev:
return CL_SUCCESS;
case visit_file:
break;
}
while (1) {
/* consume all the available input to let some of the clamd
* threads blocked on send() to be dead.
* by doing so we shouldn't deadlock on the next recv() */
fd_set rfds, wfds;
FD_ZERO(&rfds);
FD_SET(c->sockd, &rfds);
FD_ZERO(&wfds);
FD_SET(c->sockd, &wfds);
if (select(c->sockd + 1, &rfds, &wfds, NULL, NULL) < 0) {
if (errno == EINTR) continue;
free(filename);
logg("!select() failed during session: %s\n", strerror(errno));
return CL_BREAK;
}
if (FD_ISSET(c->sockd, &rfds)) {
if (dspresult(c)) {
free(filename);
return CL_BREAK;
} else
continue;
}
if (FD_ISSET(c->sockd, &wfds)) break;
}
cid = (struct SCANID *)malloc(sizeof(struct SCANID));
if (!cid) {
free(filename);
logg("!Failed to allocate scanid entry: %s\n", strerror(errno));
return CL_BREAK;
}
cid->id = ++c->lastid;
cid->file = filename;
cid->next = c->ids;
c->ids = cid;
switch (c->scantype) {
#ifdef HAVE_FD_PASSING
case FILDES:
res = send_fdpass(c->sockd, filename);
break;
#endif
case STREAM:
res = send_stream(c->sockd, filename);
break;
}
if (res <= 0) {
c->printok = 0;
c->errors++;
c->ids = cid->next;
c->lastid--;
free(cid);
free(filename);
return res ? CL_BREAK : CL_SUCCESS;
}
return CL_SUCCESS;
}
/* IDSESSION handler
* Returns non zero for serious errors, zero otherwise */
int parallel_client_scan(char *file, int scantype, int *infected, int *err, int maxlevel, int flags)
{
struct cli_ftw_cbdata data;
struct client_parallel_data cdata;
int ftw;
if ((cdata.sockd = dconnect()) < 0)
return 1;
if (sendln(cdata.sockd, "zIDSESSION", 11)) {
closesocket(cdata.sockd);
return 1;
}
cdata.infected = 0;
cdata.files = 0;
cdata.errors = 0;
cdata.scantype = scantype;
cdata.lastid = 0;
cdata.ids = NULL;
cdata.printok = printinfected ^ 1;
data.data = &cdata;
ftw = cli_ftw(file, flags, maxlevel ? maxlevel : INT_MAX, parallel_callback, &data, ftw_chkpath);
if (ftw != CL_SUCCESS) {
*err += cdata.errors;
*infected += cdata.infected;
closesocket(cdata.sockd);
return 1;
}
sendln(cdata.sockd, "zEND", 5);
while (cdata.ids && !dspresult(&cdata)) continue;
closesocket(cdata.sockd);
*infected += cdata.infected;
*err += cdata.errors;
if (cdata.ids) {
logg("!Clamd closed the connection before scanning all files.\n");
return 1;
}
if (cdata.errors)
return 1;
if (!cdata.files)
return 0;
if (cdata.printok)
logg("~%s: OK\n", file);
return 0;
}