/*
* Copyright (C) 2009 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
/* must be first because it may define _XOPEN_SOURCE */
#include "shared/fdpassing.h"
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <arpa/inet.h>
#include "libclamav/others.h"
#include "shared/actions.h"
#include "shared/output.h"
#include "proto.h"
#include "client.h"
extern struct sockaddr *mainsa;
extern int mainsasz;
extern unsigned long int maxstream;
int printinfected;
static const char *scancmd[] = { "CONTSCAN", "MULTISCAN" };
/* Connects to clamd
* Returns a FD or -1 on error */
int dconnect() {
int sockd;
if((sockd = socket(mainsa->sa_family, SOCK_STREAM, 0)) < 0) {
logg("!Can't create the socket: %s\n", strerror(errno));
return -1;
}
if(connect(sockd, (struct sockaddr *)mainsa, mainsasz) < 0) {
close(sockd);
logg("!Can't connect to clamd: %s\n", strerror(errno));
return -1;
}
return sockd;
}
/* 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("!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 ond of line.
* Should be called repeatedly untill all input is conumed
* Returns
* - the lenght 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("!Communication error\n");
else
logg("!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("!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;
}
}
}
/* 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 = open(filename, O_RDONLY))<0) {
logg("~%s: Access denied. ERROR\n", filename);
return 0;
}
} else fd = 0;
if(sendln(sockd, "zINSTREAM", 10)) 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
/* 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 */
int dsresult(int sockd, int scantype, const char *filename, int *printok) {
int infected = 0, len, beenthere = 0;
char *bol, *eol;
struct RCVLN rcv;
recvlninit(&rcv, sockd);
switch(scantype) {
case MULTI:
case CONT:
len = strlen(filename) + strlen(scancmd[scantype]) + 3;
if (!(bol = malloc(len))) {
logg("!Cannot allocate a command buffer: %s\n", strerror(errno));
return -1;
}
sprintf(bol, "z%s %s", scancmd[scantype], filename);
if(sendln(sockd, bol, len)) return -1;
free(bol);
break;
case STREAM:
len = send_stream(sockd, filename);
break;
#ifdef HAVE_FD_PASSING
case FILDES:
len = send_fdpass(sockd, filename);
break;
#endif
}
if(len <=0) {
*printok = 0;
return len;
}
while((len = recvln(&rcv, &bol, &eol))) {
if(len == -1) return -1;
beenthere = 1;
if(!filename) logg("~%s\n", bol);
if(len > 7) {
char *colon = strrchr(bol, ':');
if(!colon) {
logg("Failed to parse reply\n");
return -1;
} else if(!memcmp(eol - 7, " FOUND", 6)) {
*printok = 0;
infected++;
if(filename) {
if(scantype >= STREAM) {
logg("~%s%s\n", filename, colon);
if(action) action(filename);
} else {
logg("~%s\n", bol);
*colon = '\0';
if(action)
action(bol);
}
}
} else if(!memcmp(eol-7, " ERROR", 6)) {
*printok = 0;
if(filename) {
if(scantype >= STREAM)
logg("~%s%s\n", filename, colon);
else
logg("~%s\n", bol);
}
}
}
}
if(!beenthere) {
logg("~%s: no reply from clamd\n", filename ? filename : "STDIN");
return -1;
}
return infected;
}
/* Used by serial_callback() */
struct client_serial_data {
int infected;
int scantype;
int printok;
};
/* FTW callback for scanning in non IDSESSION mode
* Returns SUCCESS or BREAK on success, CL_EXXX on error */
static int serial_callback(struct stat *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;
switch(reason) {
case error_stat:
logg("^Can't access file %s\n", path);
return CL_SUCCESS;
case error_mem:
logg("^Memory allocation failed in ftw\n");
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. ERROR\n", path);
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);
return CL_EOPEN;
}
ret = dsresult(sockd, c->scantype, f, &c->printok);
if(filename) free(filename);
close(sockd);
if(ret < 0) 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 maxlevel, int flags) {
struct cli_ftw_cbdata data;
struct client_serial_data cdata;
int ftw;
cdata.infected = 0;
cdata.printok = printinfected^1;
cdata.scantype = scantype;
data.data = &cdata;
ftw = cli_ftw(file, flags, maxlevel ? maxlevel : INT_MAX, serial_callback, &data);
*infected += cdata.infected;
if(ftw == CL_SUCCESS || ftw == CL_BREAK) {
if(cdata.printok)
logg("~%s: OK\n", file);
return 0;
}
return 1;
}
/* Used in IDSESSION mode */
struct client_parallel_data {
int infected;
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 */
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 0;
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->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(struct stat *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;
switch(reason) {
case error_stat:
logg("^Can't access file %s\n", path);
return CL_SUCCESS;
case error_mem:
logg("^Memory allocation failed in ftw\n");
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. ERROR\n", path);
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->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 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)) {
close(cdata.sockd);
return 1;
}
cdata.infected = 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);
if(ftw != CL_SUCCESS) {
*infected += cdata.infected;
close(cdata.sockd);
return 1;
}
sendln(cdata.sockd, "zEND", 5);
while(cdata.ids && !dspresult(&cdata));
close(cdata.sockd);
*infected += cdata.infected;
if(cdata.ids) {
logg("!Clamd closed the connection before scanning all files.\n");
return 1;
}
if(cdata.printok)
logg("~%s: OK\n", file);
return 0;
}