[PATCH] Truncate debug messages

Michael Santos <>
Tue Apr 13 02:22:03 CEST 2010


When the undocumented ERL_INET_GETHOST_DEBUG environment variable
is set to 5, very long hostnames can overflow the buffer used to
construct the debug message. Truncate debug messages if they exceed
the size of the buffer.

export ERL_INET_GETHOST_DEBUG=5
inet:gethostbyname(lists:duplicate(5000,"x")).
---
 erts/etc/common/Makefile.in    |   10 +++++-----
 erts/etc/common/inet_gethost.c |    8 +++++---
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/erts/etc/common/Makefile.in b/erts/etc/common/Makefile.in
index 3db4fcb..d2a5080 100644
--- a/erts/etc/common/Makefile.in
+++ b/erts/etc/common/Makefile.in
@@ -96,9 +96,9 @@ endif
 
 # On windows we always need reentrant libraries.
 ifeq ($(TARGET),win32)
-ERLEXEC_XLIBS=-L../../lib/internal/$(TARGET) -lerts_internal_r$(ERTS_LIB_TYPEMARKER) @ERTS_INTERNAL_X_LIBS@
+ERTS_INTERNAL_LIBS=-L../../lib/internal/$(TARGET) -lerts_internal_r$(ERTS_LIB_TYPEMARKER) @ERTS_INTERNAL_X_LIBS@
 else
-ERLEXEC_XLIBS=-L../../lib/internal/$(TARGET) -lerts_internal$(ERTS_LIB_TYPEMARKER) @ERTS_INTERNAL_X_LIBS@
+ERTS_INTERNAL_LIBS=-L../../lib/internal/$(TARGET) -lerts_internal$(ERTS_LIB_TYPEMARKER) @ERTS_INTERNAL_X_LIBS@
 endif
 
 # ----------------------------------------------------
@@ -295,7 +295,7 @@ $(OBJDIR)/inet_gethost.o: inet_gethost.c
 	$(CC) $(CFLAGS) -o $@ -c inet_gethost.c
 
 $(BINDIR)/@: $(OBJDIR)/inet_gethost.o $(ENTRY_OBJ)
-	$(PURIFY) $(LD) $(LDFLAGS) $(ENTRY_LDFLAGS) -o $@ $(OBJDIR)/inet_gethost.o $(ENTRY_OBJ) $(LIBS) 
+	$(PURIFY) $(LD) $(LDFLAGS) $(ENTRY_LDFLAGS) -o $@ $(OBJDIR)/inet_gethost.o $(ENTRY_OBJ) $(LIBS) $(ERTS_INTERNAL_LIBS)
 
 $(BINDIR)/run_erl: $(OBJDIR)/safe_string.o $(OBJDIR)/run_erl.o
 	$(LD) $(LDFLAGS) -o $@ $(OBJDIR)/safe_string.o $(OBJDIR)/run_erl.o $(LIBS)
@@ -320,7 +320,7 @@ $(OBJDIR)/safe_string.o: ../unix/safe_string.c
 
 ifneq ($(TARGET),win32)
 $(BINDIR)/$(ERLEXEC): $(OBJDIR)/$(ERLEXEC).o
-	$(PURIFY) $(LD) $(LDFLAGS) -o $@ $(OBJDIR)/$(ERLEXEC).o $(ERLEXEC_XLIBS)
+	$(PURIFY) $(LD) $(LDFLAGS) -o $@ $(OBJDIR)/$(ERLEXEC).o $(ERTS_INTERNAL_LIBS)
 
 $(OBJDIR)/$(ERLEXEC).o: $(ERLEXECDIR)/$(ERLEXEC).c
 	$(CC) -I$(EMUDIR) $(CFLAGS) -o $@ -c $(ERLEXECDIR)/$(ERLEXEC).c
@@ -360,7 +360,7 @@ $(OBJDIR)/escript.o: escript.c
 ifeq ($(TARGET),win32)
 
 $(BINDIR)/$(ERLEXEC): $(OBJDIR)/erlexec.o $(OBJDIR)/win_erlexec.o $(OBJDIR)/init_file.o  $(OBJDIR)/$(ERLRES_OBJ)
-	$(LD) -dll $(LDFLAGS) -o $@ $(OBJDIR)/erlexec.o $(OBJDIR)/win_erlexec.o $(OBJDIR)/init_file.o $(OBJDIR)/$(ERLRES_OBJ) $(ERLEXEC_XLIBS)
+	$(LD) -dll $(LDFLAGS) -o $@ $(OBJDIR)/erlexec.o $(OBJDIR)/win_erlexec.o $(OBJDIR)/init_file.o $(OBJDIR)/$(ERLRES_OBJ) $(ERTS_INTERNAL_LIBS)
 
 $(BINDIR)/@: $(OBJDIR)/erl.o $(OBJDIR)/init_file.o $(OBJDIR)/$(ERLRES_OBJ)
 	$(LD) $(LDFLAGS) -o $@ $(OBJDIR)/erl.o $(OBJDIR)/init_file.o $(OBJDIR)/$(ERLRES_OBJ) 
diff --git a/erts/etc/common/inet_gethost.c b/erts/etc/common/inet_gethost.c
index ff16ee0..bd2be47 100644
--- a/erts/etc/common/inet_gethost.c
+++ b/erts/etc/common/inet_gethost.c
@@ -52,6 +52,8 @@
 #  include "config.h"
 #endif
 
+#include "erl_printf.h"
+
 #ifdef WIN32
 
 #define WIN32_LEAN_AND_MEAN
@@ -2552,7 +2554,7 @@ static void debugf(char *format, ...)
     sprintf(buff,"%s[%d] (DEBUG):",program_name,(int) getpid());
 #endif
     ptr = buff + strlen(buff);
-    vsprintf(ptr,format,ap);
+    erts_vsnprintf(ptr,sizeof(buff)-strlen(buff)-2,format,ap);
     strcat(ptr,"\r\n");
 #ifdef WIN32
     if (debug_console_allocated != INVALID_HANDLE_VALUE) {
@@ -2574,7 +2576,7 @@ static void warning(char *format, ...)
     va_start(ap,format);
     sprintf(buff,"%s[%d]: WARNING:",program_name, (int) getpid());
     ptr = buff + strlen(buff);
-    vsprintf(ptr,format,ap);
+    erts_vsnprintf(ptr,sizeof(buff)-strlen(buff)-2,format,ap);
     strcat(ptr,"\r\n");
 #ifdef WIN32
     {
@@ -2596,7 +2598,7 @@ static void fatal(char *format, ...)
     va_start(ap,format);
     sprintf(buff,"%s[%d]: FATAL ERROR:",program_name, (int) getpid());
     ptr = buff + strlen(buff);
-    vsprintf(ptr,format,ap);
+    erts_vsnprintf(ptr,sizeof(buff)-strlen(buff)-2,format,ap);
     strcat(ptr,"\r\n");
 #ifdef WIN32
     {
-- 
1.5.6.4



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