[Pkg-clamav-commits] [SCM] Debian repository for ClamAV branch, debian/unstable, updated. debian/0.95+dfsg-1-6156-g094ec9b

[Tomasz Kojm]

The following commit has been merged in the debian/unstable branch:
commit 6d3c5bec1d2d4cd0211e7f6e2701750ad39e4339
Author: Tomasz Kojm <tkojm at clamav.net>
Date:   Tue Sep 1 20:52:13 2009 +0200

    libclamav: use BM matcher in offset mode for PE files larger than 256kB
    (10% speedup on average; 30-40% for large executables)

diff --git a/ChangeLog b/ChangeLog
index 3b4141b..4b19fa8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Sep  1 20:50:12 CEST 2009 (tk)
+----------------------------------
+ * libclamav: use BM matcher in offset mode for PE files larger than 256kB
+	      (10% speedup on average; 30-40% for large executables)
+
 Tue Sep  1 11:11:43 CEST 2009 (tk)
 ----------------------------------
  * libclamav: in bm_offmode only load sigs with non-floating absolute and
diff --git a/libclamav/default.h b/libclamav/default.h
index 8641fe9..c1738c5 100644
--- a/libclamav/default.h
+++ b/libclamav/default.h
@@ -28,6 +28,8 @@
 #define CLI_DEFAULT_LSIG_BUFSIZE    32768
 #define CLI_DEFAULT_DBIO_BUFSIZE    CLI_DEFAULT_LSIG_BUFSIZE + 1
 
+#define CLI_DEFAULT_BM_OFFMODE_FSIZE	262144
+
 #define CLI_DEFAULT_MAXSCANSIZE	    104857600
 #define CLI_DEFAULT_MAXFILESIZE	    26214400
 #define CLI_DEFAULT_MAXRECLEVEL	    16
diff --git a/libclamav/matcher-bm.c b/libclamav/matcher-bm.c
index 49b248f..aa876fe 100644
--- a/libclamav/matcher-bm.c
+++ b/libclamav/matcher-bm.c
@@ -369,7 +369,7 @@ int cli_bm_scanbuff(const unsigned char *buffer, uint32_t length, const char **v
 	    shift = 1;
 	}
 
-	if(root->bm_offmode) {
+	if(offdata) {
 	    off = offset + i - BM_MIN_LENGTH + BM_BLOCK_SIZE;
 	    for(; off >= offdata->offtab[offdata->pos] && offdata->pos < offdata->cnt; offdata->pos++);
 	    if(offdata->pos == offdata->cnt || off >= offdata->offtab[offdata->pos])
diff --git a/libclamav/matcher.c b/libclamav/matcher.c
index 0e4cc04..9573f8f 100644
--- a/libclamav/matcher.c
+++ b/libclamav/matcher.c
@@ -322,7 +322,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 {
  	unsigned char *buffer, *buff, *endbl, *upt;
 	int ret = CL_CLEAN, type = CL_CLEAN, bytes;
-	unsigned int i, evalcnt;
+	unsigned int i, evalcnt, bm_offmode = 0;
 	uint32_t buffersize, length, maxpatlen, shift = 0, offset = 0;
 	uint64_t evalids;
 	struct cli_ac_data gdata, tdata;
@@ -330,6 +330,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 	cli_md5_ctx md5ctx;
 	unsigned char digest[16];
 	struct cli_matcher *groot = NULL, *troot = NULL;
+	struct stat sb;
 
 
     if(!ctx->engine) {
@@ -378,11 +379,18 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 		cli_ac_freedata(&gdata);
 	    return ret;
 	}
-	if(troot->bm_offmode && (ret = cli_bm_initoff(troot, &toff, desc))) {
-	    if(!ftonly)
-		cli_ac_freedata(&gdata);
-	    cli_ac_freedata(&tdata);
-	    return ret;
+	if(troot->bm_offmode) {
+	    if(fstat(desc, &sb) != -1) {
+		if(sb.st_size >= CLI_DEFAULT_BM_OFFMODE_FSIZE) {
+		    if((ret = cli_bm_initoff(troot, &toff, desc))) {
+			if(!ftonly)
+			    cli_ac_freedata(&gdata);
+			cli_ac_freedata(&tdata);
+			return ret;
+		    }
+		    bm_offmode = 1;
+		}
+	    }
 	}
     }
 
@@ -406,7 +414,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 	    length += maxpatlen;
 
 	if(troot) {
-	    if(troot->ac_only || (ret = cli_bm_scanbuff(upt, length, ctx->virname, troot, offset, desc, &toff)) != CL_VIRUS)
+	    if(troot->ac_only || (ret = cli_bm_scanbuff(upt, length, ctx->virname, troot, offset, desc, bm_offmode ? &toff : NULL)) != CL_VIRUS)
 		ret = cli_ac_scanbuff(upt, length, ctx->virname, NULL, NULL, troot, &tdata, offset, ftype, ftoffset, acmode, NULL);
 
 	    if(ret == CL_VIRUS) {
@@ -414,7 +422,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 		if(!ftonly)
 		    cli_ac_freedata(&gdata);
 		cli_ac_freedata(&tdata);
-		if(troot->bm_offmode)
+		if(bm_offmode)
 		    cli_bm_freeoff(&toff);
 
 		if(cli_checkfp(desc, ctx))
@@ -433,7 +441,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 		cli_ac_freedata(&gdata);
 		if(troot) {
 		    cli_ac_freedata(&tdata);
-		    if(troot->bm_offmode)
+		    if(bm_offmode)
 			cli_bm_freeoff(&toff);
 		}
 		if(cli_checkfp(desc, ctx))
@@ -480,7 +488,7 @@ int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struc
 	    }
 	}
 	cli_ac_freedata(&tdata);
-	if(troot->bm_offmode)
+	if(bm_offmode)
 	    cli_bm_freeoff(&toff);
     }
 

-- 
Debian repository for ClamAV