From e5a71411f3cab38fd8222c6a51d4791c330d5de7 Mon Sep 17 00:00:00 2001
From: Arthur de Jong <arthur@arthurdejong.org>
Date: Wed, 27 Dec 2006 09:48:43 +0000
Subject: do not allocate new memory with malloc() for each request with a
 string parameter but use a buffer allocated on the stack instead (this
 simplifies free()-ing the buffer(s) in case of problems)

git-svn-id: http://arthurdejong.org/svn/nss-pam-ldapd/nss-ldapd@204 ef36b2f9-881f-0410-afb5-c4e39611909c
---
 nslcd-common.h   | 31 ++++++++++++++++---------------
 nslcd/alias.c    |  6 ++----
 nslcd/common.h   |  4 ++--
 nslcd/ether.c    |  6 ++----
 nslcd/group.c    | 15 ++++-----------
 nslcd/host.c     |  6 ++----
 nslcd/netgroup.c |  4 ++--
 nslcd/network.c  |  7 ++-----
 nslcd/passwd.c   |  7 ++-----
 nslcd/protocol.c |  6 ++----
 nslcd/rpc.c      |  6 ++----
 nslcd/service.c  | 15 +++++----------
 nslcd/shadow.c   |  6 ++----
 13 files changed, 45 insertions(+), 74 deletions(-)

diff --git a/nslcd-common.h b/nslcd-common.h
index 25efd83..ee2e1d8 100644
--- a/nslcd-common.h
+++ b/nslcd-common.h
@@ -150,9 +150,10 @@ static void debug_dump(const void *ptr,size_t size)
 #define BUF_CHECK(fp,sz) \
   if ((bufptr+(size_t)(sz))>buflen) \
   { \
-    DEBUG_PRINT("READ       : buffer error: %d bytes missing",((sz)-(buflen))); \
+    /* will not fit */ \
+    DEBUG_PRINT("READ       : buffer error: %d bytes too large",((sz)-(buflen))); \
     ERROR_OUT_BUFERROR(fp); \
-  } /* will not fit */
+  }
 
 /* move the buffer pointer */
 #define BUF_SKIP(sz) \
@@ -176,24 +177,24 @@ static void debug_dump(const void *ptr,size_t size)
   (field)=BUF_CUR; \
   BUF_SKIP(tmpint32+1);
 
-/* read a string from the stream dynamically allocating memory
-   for the string (don't forget to call free() later on) */
-#define READ_STRING_ALLOC(fp,field) \
+/* read a string in a fixed-size "normal" buffer */
+#define READ_STRING_BUF2(fp,buffer,buflen) \
   /* read the size of the string */ \
   READ_TYPE(fp,tmpint32,int32_t); \
-  /* allocate memory */ \
-  (field)=(char *)malloc((size_t)(tmpint32+1)); \
-  if ((field)==NULL) \
+  DEBUG_PRINT("READ_STRING: var="__STRING(buffer)" strlen=%d",tmpint32); \
+  /* check if read would fit */ \
+  if (((size_t)tmpint32)>=(buflen)) \
   { \
-    DEBUG_PRINT("READ_STRING: var="__STRING(field)" malloc() error: %s",strerror(errno)); \
-    ERROR_OUT_ALLOCERROR(fp); \
-  } /* problem allocating */ \
+    /* will not fit */ \
+    DEBUG_PRINT("READ       : buffer error: %d bytes too large",(tmpint32-(buflen))+1); \
+    ERROR_OUT_BUFERROR(fp); \
+  } \
   /* read string from the stream */ \
   if (tmpint32>0) \
-    { READ(fp,(field),(size_t)tmpint32); } \
-  /* null-terminate string */ \
-  (field)[tmpint32]='\0'; \
-  DEBUG_PRINT("READ_STRING: var="__STRING(field)" string=\"%s\"",(field));
+    { READ(fp,buffer,(size_t)tmpint32); } \
+  /* null-terminate string in buffer */ \
+  buffer[tmpint32]='\0'; \
+  DEBUG_PRINT("READ_STRING: var="__STRING(buffer)" string=\"%s\"",buffer);
 
 /* read an array from a stram and store the length of the
    array in num (size for the array is allocated) */
diff --git a/nslcd/alias.c b/nslcd/alias.c
index 4698f1b..2bc0936 100644
--- a/nslcd/alias.c
+++ b/nslcd/alias.c
@@ -80,10 +80,10 @@ static int write_alias(LDAPMessage *e,struct ldap_state *pvt,FILE *fp)
 int nslcd_alias_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_alias_byname(%s)",name);
   /* write the response header */
@@ -94,8 +94,6 @@ int nslcd_alias_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   _nss_ldap_searchbyname(&a,_nss_ldap_filt_getaliasbyname,LM_ALIASES,fp,write_alias);
-  /* no more need for this */
-  free(name);
   WRITE_FLUSH(fp);
   /* we're done */
   return 0;
diff --git a/nslcd/common.h b/nslcd/common.h
index 42f47ea..374cf55 100644
--- a/nslcd/common.h
+++ b/nslcd/common.h
@@ -48,8 +48,8 @@ int nss2nslcd(enum nss_status code);
   log_log(LOG_WARNING,"error reading from client"); \
   return -1;
 
-#define ERROR_OUT_ALLOCERROR(fp) \
-  log_log(LOG_ERR,"error allocating memory"); \
+#define ERROR_OUT_BUFERROR(fp) \
+  log_log(LOG_WARNING,"client supplied argument too large"); \
   return -1;
 
 
diff --git a/nslcd/ether.c b/nslcd/ether.c
index ab7b870..c818a6d 100644
--- a/nslcd/ether.c
+++ b/nslcd/ether.c
@@ -128,7 +128,7 @@ _nss_ldap_parse_ether (LDAPMessage * e,
 int nslcd_ether_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct ether result;
@@ -136,7 +136,7 @@ int nslcd_ether_byname(FILE *fp)
   int errnop;
   int retv;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_ether_byname(%s)",name);
   /* write the response header */
@@ -147,8 +147,6 @@ int nslcd_ether_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_gethostton,LM_ETHERS,_nss_ldap_parse_ether));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/group.c b/nslcd/group.c
index faf7007..1643d9e 100644
--- a/nslcd/group.c
+++ b/nslcd/group.c
@@ -1059,7 +1059,7 @@ static enum nss_status group_bymember(const char *user, long int *start,
 int nslcd_group_byname(FILE *fp)
 {
   int32_t tmpint32,tmp2int32,tmp3int32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct group result;
@@ -1067,8 +1067,7 @@ int nslcd_group_byname(FILE *fp)
   int errnop;
   int retv;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
-  /* FIXME: free() this buffer somewhere */
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_group_byname(%s)",name);
   /* static buffer size check */
@@ -1082,8 +1081,6 @@ int nslcd_group_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getgrnam,LM_GROUP,_nss_ldap_parse_gr));
-  /* no more need for this */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,NSLCD_VERSION);
   WRITE_INT32(fp,NSLCD_ACTION_GROUP_BYNAME);
@@ -1109,7 +1106,6 @@ int nslcd_group_bygid(FILE *fp)
   int retv;
   /* read request parameters */
   READ_TYPE(fp,gid,gid_t);
-  /* FIXME: free() this buffer somewhere */
   /* log call */
   log_log(LOG_DEBUG,"nslcd_group_bygid(%d)",(int)gid);
   /* static buffer size check */
@@ -1139,7 +1135,7 @@ int nslcd_group_bygid(FILE *fp)
 int nslcd_group_bymember(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   /* these are here for now until we rewrite the LDAP code */
   int errnop;
   int retv;
@@ -1147,8 +1143,7 @@ int nslcd_group_bymember(FILE *fp)
   long int i;
   gid_t groupsp[1024];
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
-  /* FIXME: free() this buffer somewhere */
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_group_bymember(%s)",name);
   /* do the LDAP request */
@@ -1189,8 +1184,6 @@ int nslcd_group_bymember(FILE *fp)
     WRITE_INT32(fp,retv);
   }
   WRITE_FLUSH(fp);
-  /* no more need for this */
-  free(name);
   /* we're done */
   return 0;
 }
diff --git a/nslcd/host.c b/nslcd/host.c
index ec04bf2..60dda78 100644
--- a/nslcd/host.c
+++ b/nslcd/host.c
@@ -247,14 +247,14 @@ _nss_ldap_parse_hostv6 (LDAPMessage * e,
 int nslcd_host_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   int retv;
   struct hostent result;
   char buffer[1024];
   int errnop;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_host_byname(%s)",name);
   /* write the response header */
@@ -270,8 +270,6 @@ int nslcd_host_byname(FILE *fp)
 #else
                      _nss_ldap_parse_hostv4));
 #endif
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/netgroup.c b/nslcd/netgroup.c
index e79657d..3641783 100644
--- a/nslcd/netgroup.c
+++ b/nslcd/netgroup.c
@@ -291,7 +291,7 @@ int nslcd_netgroup_byname(FILE *fp)
 
   int32_t tmpint32;
   static struct ent_context *netgroup_context=NULL;
-  char *name;
+  char name[256];
   /* these are here for now until we rewrite the LDAP code */
   struct __netgrent result;
   char buffer[1024];
@@ -299,7 +299,7 @@ int nslcd_netgroup_byname(FILE *fp)
   struct ldap_args a;
   enum nss_status stat=NSS_STATUS_SUCCESS;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_netgroup_byname(%s)",name);
   /* write the response header */
diff --git a/nslcd/network.c b/nslcd/network.c
index e44a3e1..6b13ad3 100644
--- a/nslcd/network.c
+++ b/nslcd/network.c
@@ -111,18 +111,17 @@ _nss_ldap_parse_net (LDAPMessage * e,
 int nslcd_network_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   int retv;
   struct netent result;
   char buffer[1024];
   int errnop;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_network_byname(%s)",name);
   /* write the response header */
-  /* FIXME: free(name) when one of these writes fails */
   WRITE_INT32(fp,NSLCD_VERSION);
   WRITE_INT32(fp,NSLCD_ACTION_NETWORK_BYNAME);
   /* do the LDAP request */
@@ -130,8 +129,6 @@ int nslcd_network_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getnetbyname,LM_NETWORKS,_nss_ldap_parse_net));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/passwd.c b/nslcd/passwd.c
index eeca355..c393ab6 100644
--- a/nslcd/passwd.c
+++ b/nslcd/passwd.c
@@ -173,7 +173,7 @@ static enum nss_status _nss_ldap_parse_pw (LDAPMessage * e,
 int nslcd_passwd_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   /* these are here for now until we rewrite the LDAP code */
   struct passwd result;
   char buffer[1024];
@@ -181,8 +181,7 @@ int nslcd_passwd_byname(FILE *fp)
   int retv;
   struct ldap_args a;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
-  /* FIXME: free() this buffer somewhere */
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_passwd_byname(%s)",name);
   /* do the LDAP request */
@@ -190,8 +189,6 @@ int nslcd_passwd_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getpwnam,LM_PASSWD,_nss_ldap_parse_pw));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,NSLCD_VERSION);
   WRITE_INT32(fp,NSLCD_ACTION_PASSWD_BYNAME);
diff --git a/nslcd/protocol.c b/nslcd/protocol.c
index 71ce52d..857f7cd 100644
--- a/nslcd/protocol.c
+++ b/nslcd/protocol.c
@@ -96,7 +96,7 @@ static enum nss_status _nss_ldap_parse_proto (LDAPMessage *e,
 int nslcd_protocol_byname(FILE *fp)
 {
   int32_t tmpint32,tmp2int32,tmp3int32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct protoent result;
@@ -104,7 +104,7 @@ int nslcd_protocol_byname(FILE *fp)
   int errnop;
   int retv;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_protocol_byname(%s)",name);
   /* write the response header */
@@ -115,8 +115,6 @@ int nslcd_protocol_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getprotobyname,LM_PROTOCOLS,_nss_ldap_parse_proto));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/rpc.c b/nslcd/rpc.c
index b58cca7..27b2b62 100644
--- a/nslcd/rpc.c
+++ b/nslcd/rpc.c
@@ -108,7 +108,7 @@ static enum nss_status _nss_ldap_parse_rpc (LDAPMessage * e,
 int nslcd_rpc_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct rpcent result;
@@ -116,7 +116,7 @@ int nslcd_rpc_byname(FILE *fp)
   int errnop;
   int retv;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_rpc_byname(%s)",name);
   /* write the response header */
@@ -127,8 +127,6 @@ int nslcd_rpc_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getrpcbyname,LM_RPC,_nss_ldap_parse_rpc));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/service.c b/nslcd/service.c
index 7739b8e..59065aa 100644
--- a/nslcd/service.c
+++ b/nslcd/service.c
@@ -192,7 +192,7 @@ static enum nss_status _nss_ldap_parse_serv (LDAPMessage *e,
 int nslcd_service_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name,*protocol;
+  char name[256],protocol[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct servent result;
@@ -200,8 +200,8 @@ int nslcd_service_byname(FILE *fp)
   int errnop;
   int retv;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
-  READ_STRING_ALLOC(fp,protocol);
+  READ_STRING_BUF2(fp,name,sizeof(name));
+  READ_STRING_BUF2(fp,protocol,sizeof(protocol));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_service_byname(%s,%s)",name,protocol);
   /* write the response header */
@@ -215,9 +215,6 @@ int nslcd_service_byname(FILE *fp)
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,
                  ((strlen(protocol)==0)?_nss_ldap_filt_getservbyname:_nss_ldap_filt_getservbynameproto),
                  LM_SERVICES,_nss_ldap_parse_serv));
-  /* no more need for these strings */
-  free(name);
-  free(protocol);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
@@ -231,7 +228,7 @@ int nslcd_service_bynumber(FILE *fp)
 {
   int32_t tmpint32;
   int number;
-  char *protocol;
+  char protocol[256];
   struct ldap_args a;
   /* these are here for now until we rewrite the LDAP code */
   struct servent result;
@@ -240,7 +237,7 @@ int nslcd_service_bynumber(FILE *fp)
   int retv;
   /* read request parameters */
   READ_INT32(fp,number);
-  READ_STRING_ALLOC(fp,protocol);
+  READ_STRING_BUF2(fp,protocol,sizeof(protocol));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_service_bynumber(%d,%s)",number,protocol);
   /* write the response header */
@@ -254,8 +251,6 @@ int nslcd_service_bynumber(FILE *fp)
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,
                  ((strlen(protocol)==0)?_nss_ldap_filt_getservbyport:_nss_ldap_filt_getservbyportproto),
                  LM_SERVICES,_nss_ldap_parse_serv));
-  /* no more need for this string */
-  free(protocol);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
diff --git a/nslcd/shadow.c b/nslcd/shadow.c
index d1b22bd..cd3a2ee 100644
--- a/nslcd/shadow.c
+++ b/nslcd/shadow.c
@@ -122,14 +122,14 @@ static enum nss_status _nss_ldap_parse_sp(LDAPMessage *e,
 int nslcd_shadow_byname(FILE *fp)
 {
   int32_t tmpint32;
-  char *name;
+  char name[256];
   struct ldap_args a;
   int retv;
   struct spwd result;
   char buffer[1024];
   int errnop;
   /* read request parameters */
-  READ_STRING_ALLOC(fp,name);
+  READ_STRING_BUF2(fp,name,sizeof(name));
   /* log call */
   log_log(LOG_DEBUG,"nslcd_shadow_byname(%s)",name);
   /* write the response header */
@@ -140,8 +140,6 @@ int nslcd_shadow_byname(FILE *fp)
   LA_STRING(a)=name;
   LA_TYPE(a)=LA_TYPE_STRING;
   retv=nss2nslcd(_nss_ldap_getbyname(&a,&result,buffer,1024,&errnop,_nss_ldap_filt_getspnam,LM_SHADOW,_nss_ldap_parse_sp));
-  /* no more need for this string */
-  free(name);
   /* write the response */
   WRITE_INT32(fp,retv);
   if (retv==NSLCD_RESULT_SUCCESS)
-- 
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