denyhosts/clamav/common/clamdcom.c

484 lines
14 KiB
C

/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2009-2013 Sourcefire, Inc.
*
* Author: 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
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <errno.h>
#ifndef _WIN32
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netdb.h>
#endif
#include "clamav.h"
#include "actions.h"
#include "output.h"
#include "clamdcom.h"
#ifndef _WIN32
struct sockaddr_un nixsock;
#endif
static const char *scancmd[] = {"CONTSCAN", "MULTISCAN", "INSTREAM", "FILDES", "ALLMATCHSCAN"};
/* Sends bytes over a socket
* Returns 0 on success */
int sendln(int sockd, const char *line, unsigned int len)
{
while (len) {
int sent = send(sockd, line, len, 0);
if (sent <= 0) {
if (sent && errno == EINTR) continue;
logg(LOGG_ERROR, "Can't send to clamd: %s\n", strerror(errno));
return 1;
}
line += sent;
len -= sent;
}
return 0;
}
/* Inits a RECVLN struct before it can be used in recvln() - see below */
void recvlninit(struct RCVLN *s, int sockd)
{
s->sockd = sockd;
s->bol = s->cur = s->buf;
s->r = 0;
}
/* Receives a full (terminated with \0) line from a socket
* Sets rbol to the begin of the received line, and optionally
* reol to the end of line.
* Should be called repeatedly until all input is consumed
* Returns:
* - the length of the line (a positive number) on success
* - 0 if the connection is closed
* - -1 on error
*/
int recvln(struct RCVLN *s, char **rbol, char **reol)
{
char *eol;
while (1) {
if (!s->r) {
s->r = recv(s->sockd, s->cur, sizeof(s->buf) - (s->cur - s->buf), 0);
if (s->r <= 0) {
if (s->r && errno == EINTR) {
s->r = 0;
continue;
}
if (s->r || s->cur != s->buf) {
*s->cur = '\0';
if (strcmp(s->buf, "UNKNOWN COMMAND\n"))
logg(LOGG_ERROR, "Communication error\n");
else
logg(LOGG_ERROR, "Command rejected by clamd (wrong clamd version?)\n");
return -1;
}
return 0;
}
}
if ((eol = memchr(s->cur, 0, s->r))) {
int ret = 0;
eol++;
s->r -= eol - s->cur;
*rbol = s->bol;
if (reol) *reol = eol;
ret = eol - s->bol;
if (s->r)
s->bol = s->cur = eol;
else
s->bol = s->cur = s->buf;
return ret;
}
s->r += s->cur - s->bol;
if (!eol && s->r == sizeof(s->buf)) {
logg(LOGG_ERROR, "Overlong reply from clamd\n");
return -1;
}
if (!eol) {
if (s->buf != s->bol) { /* old memmove sux */
memmove(s->buf, s->bol, s->r);
s->bol = s->buf;
}
s->cur = &s->bol[s->r];
s->r = 0;
}
}
}
/* Determines if a path should be excluded
* 0: scan, 1: skip */
int chkpath(const char *path, struct optstruct *clamdopts)
{
int status = 0;
const struct optstruct *opt;
char *real_path = NULL;
if (!path) {
status = 1;
goto done;
}
if ((opt = optget(clamdopts, "ExcludePath"))->enabled) {
while (opt) {
if (match_regex(path, opt->strarg) == 1) {
logg(LOGG_DEBUG, "%s: Excluded\n", path);
status = 1;
goto done;
}
opt = opt->nextarg;
}
}
done:
if (NULL != real_path) {
free(real_path);
}
return status;
}
#ifdef HAVE_FD_PASSING
/* Issues a FILDES command and pass a FD to clamd
* Returns >0 on success, 0 soft fail, -1 hard fail */
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;
const char zFILDES[] = "zFILDES";
if (filename) {
if ((fd = open(filename, O_RDONLY)) < 0) {
logg(LOGG_INFO, "%s: Failed to open file\n", filename);
return 0;
}
} else
fd = 0;
if (sendln(sockd, zFILDES, sizeof(zFILDES))) {
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(LOGG_ERROR, "FD send failed: %s\n", strerror(errno));
close(fd);
return -1;
}
close(fd);
return 1;
}
#endif
/* Issues an INSTREAM command to clamd and streams the given file
* Returns >0 on success, 0 soft fail, -1 hard fail */
int send_stream(int sockd, const char *filename, struct optstruct *clamdopts)
{
uint32_t buf[BUFSIZ / sizeof(uint32_t)];
int fd, len;
unsigned long int todo = optget(clamdopts, "StreamMaxLength")->numarg;
const char zINSTREAM[] = "zINSTREAM";
if (filename) {
if ((fd = safe_open(filename, O_RDONLY | O_BINARY)) < 0) {
logg(LOGG_INFO, "%s: Failed to open file. ERROR\n", filename);
return 0;
}
} else {
/* Read stream from STDIN */
fd = 0;
}
if (sendln(sockd, zINSTREAM, sizeof(zINSTREAM))) {
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(LOGG_ERROR, "Failed to read from %s.\n", filename ? filename : "STDIN");
return 0;
}
*buf = 0;
sendln(sockd, (const char *)buf, 4);
return 1;
}
/* Connects to clamd
* Returns a FD or -1 on error */
int dconnect(struct optstruct *clamdopts)
{
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(LOGG_ERROR, "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(LOGG_ERROR, "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(LOGG_ERROR, "Can't create the socket: %s\n", strerror(errno));
continue;
}
if (connect(sockd, p->ai_addr, p->ai_addrlen) < 0) {
logg(LOGG_ERROR, "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;
}
/* 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, struct optstruct *clamdopts)
{
int infected = 0, len = 0, beenthere = 0;
char *bol, *eol;
struct RCVLN rcv;
STATBUF sb;
if (filename) {
if (1 == chkpath(filename, clamdopts)) {
goto done;
}
}
recvlninit(&rcv, sockd);
switch (scantype) {
case MULTI:
case CONT:
case ALLMATCH:
if (!filename) {
logg(LOGG_INFO, "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(LOGG_ERROR, "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, clamdopts);
break;
#ifdef HAVE_FD_PASSING
case FILDES:
/* NULL filename safe in send_fdpass() */
len = send_fdpass(sockd, filename);
break;
#endif
}
if (len <= 0) {
if (printok)
*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(LOGG_INFO, "%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(LOGG_INFO, "clamd replied \"UNKNOWN COMMAND\". Command was %s\n",
(scantype < 0 || scantype > MAX_SCANTYPE) ? "unidentified" : scancmd[scantype]);
else
logg(LOGG_INFO, "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;
if (printok)
*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(LOGG_INFO, "%s%s FOUND\n", filename, colon);
if (action) action(filename);
} else {
logg(LOGG_INFO, "%s FOUND\n", bol);
*colon = '\0';
if (action)
action(bol);
}
}
} else if (!memcmp(eol - 7, " ERROR", 6)) {
if (errors)
(*errors)++;
if (printok)
*printok = 0;
if (filename) {
if (scantype >= STREAM)
logg(LOGG_INFO, "%s%s\n", filename, colon);
else
logg(LOGG_INFO, "%s\n", bol);
}
}
}
}
if (!beenthere) {
if (!filename) {
logg(LOGG_INFO, "STDIN: noreply from clamd\n.");
infected = -1;
goto done;
}
if (CLAMSTAT(filename, &sb) == -1) {
logg(LOGG_INFO, "%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(LOGG_INFO, "%s: no reply from clamd\n", filename);
infected = -1;
goto done;
}
}
done:
return infected;
}