heimdal: Fix size types and array access

This fixes compilation with -Wstrict-overflow=2.

with CFLAGS="-O3 -Werror=strict-overflow -Wstrict-overflow=2"
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.10) gives:

addr_families.c: In function ‘krb5_sockaddr2address’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:851:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_sockaddr2address (krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_sockaddr2port’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:879:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_sockaddr2port (krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_addr2sockaddr’:
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:914:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_addr2sockaddr (krb5_context context,
 ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_max_sockaddr_size’:
addr_families.c:955:2: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
  for(a = at; a < at + num_addrs; ++a)
  ^
addr_families.c:950:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_max_sockaddr_size (void)
 ^
addr_families.c:955:2: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
  for(a = at; a < at + num_addrs; ++a)
  ^
addr_families.c:955:2: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c:955:2: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_sockaddr_uninteresting’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:974:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_sockaddr_uninteresting(const struct sockaddr *sa)
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_sockaddr_is_loopback’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:983:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_sockaddr_is_loopback(const struct sockaddr *sa)
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_h_addr2sockaddr’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1011:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_h_addr2sockaddr (krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_h_addr2addr’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1042:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_h_addr2addr (krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_anyaddr’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1073:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_anyaddr (krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_print_address’:
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1108:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_print_address (const krb5_address *addr,
 ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_address_order’:
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1238:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_address_order(krb5_context context,
 ^
addr_families.c:1238:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c: In function ‘krb5_free_address’:
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1333:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_free_address(krb5_context context,
 ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_copy_address’:
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1383:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_copy_address(krb5_context context,
 ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:820:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
addr_families.c: In function ‘krb5_address_prefixlen_boundary’:
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:1537:1: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
 krb5_address_prefixlen_boundary(krb5_context context,
 ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
     for (a = at; a < at + num_addrs; ++a)
     ^
addr_families.c:831:5: warning: assuming pointer wraparound does not occur when comparing P +- C1 with P +- C2 [-Wstrict-overflow]
  CC       libkrb5_la-config_file.lo

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(Similar to Samba commit aa17db1f4061920512396032fcd3c7c8a4a8f38f)

lib/krb5/addr_families.c

@@ -804,7 +804,7 @@ static struct addr_operations at[] = {
     }
 };
 
-static int num_addrs = sizeof(at) / sizeof(at[0]);
+static size_t num_addrs = sizeof(at) / sizeof(at[0]);
 
 static size_t max_sockaddr_size = 0;
 
@@ -815,22 +815,24 @@ static size_t max_sockaddr_size = 0;
 static struct addr_operations *
 find_af(int af)
 {
-    struct addr_operations *a;
+    size_t i;
 
-    for (a = at; a < at + num_addrs; ++a)
+    for (i = 0; i < num_addrs; i++) {
-	if (af == a->af)
+	if (af == at[i].af)
-	    return a;
+	    return &at[i];
+    }
     return NULL;
 }
 
 static struct addr_operations *
 find_atype(krb5_address_type atype)
 {
-    struct addr_operations *a;
+    size_t i;
 
-    for (a = at; a < at + num_addrs; ++a)
+    for (i = 0; i < num_addrs; i++) {
-	if (atype == a->atype)
+	if (atype == at[i].atype)
-	    return a;
+	    return &at[i];
+    }
     return NULL;
 }
 
@@ -950,10 +952,10 @@ KRB5_LIB_FUNCTION size_t KRB5_LIB_CALL
 krb5_max_sockaddr_size (void)
 {
     if (max_sockaddr_size == 0) {
-	struct addr_operations *a;
+	size_t i;
 
-	for(a = at; a < at + num_addrs; ++a)
+	for (i = 0; i < num_addrs; i++)
-	    max_sockaddr_size = max(max_sockaddr_size, a->max_sockaddr_size);
+	    max_sockaddr_size = max(max_sockaddr_size, at[i].max_sockaddr_size);
     }
     return max_sockaddr_size;
 }