Filter: add startswith/endswith operations

Author: sedmicha

src/filter/operations/str.c

@@ -88,8 +88,19 @@ contains_str(fds_filter_value_u *big, fds_filter_value_u *little, fds_filter_val
     result->b = strnnstr(big->str.chars, little->str.chars, big->str.len, little->str.len) != NULL;
 }
 
+void
+startswith_str(fds_filter_value_u *big, fds_filter_value_u *little, fds_filter_value_u *result)
+{
+    result->b = (big->str.len >= little->str.len
+        && memcmp(big->str.chars, little->str.chars, little->str.len) == 0);
+}
 
-
+void
+endswith_str(fds_filter_value_u *big, fds_filter_value_u *little, fds_filter_value_u *result)
+{
+    result->b = (big->str.len >= little->str.len
+        && memcmp(&big->str.chars[big->str.len - little->str.len], little->str.chars, little->str.len) == 0);
+}
 
 void
 str_in_list(fds_filter_value_u *item, fds_filter_value_u *list, fds_filter_value_u *result)
@@ -136,6 +147,8 @@ const fds_filter_op_s str_operations[] = {
     FDS_FILTER_DEF_BINARY_OP(FDS_FDT_STR, "!=", FDS_FDT_STR, ne_str, FDS_FDT_BOOL),
 
     FDS_FILTER_DEF_BINARY_OP(FDS_FDT_STR, "contains", FDS_FDT_STR, contains_str, FDS_FDT_BOOL),
+    FDS_FILTER_DEF_BINARY_OP(FDS_FDT_STR, "startswith", FDS_FDT_STR, startswith_str, FDS_FDT_BOOL),
+    FDS_FILTER_DEF_BINARY_OP(FDS_FDT_STR, "endswith", FDS_FDT_STR, endswith_str, FDS_FDT_BOOL),
 
     FDS_FILTER_DEF_BINARY_OP(FDS_FDT_STR, "in", FDS_FDT_LIST | FDS_FDT_STR, str_in_list, FDS_FDT_BOOL),
 

src/filter/parser.c

@@ -88,6 +88,8 @@ struct operator_s op_parse_def_table[] = {
     { "exists"  , 2, OP_KIND_PREFIX, OP_ASSOC_NONE },
     { "in"      , 2, OP_KIND_INFIX , OP_ASSOC_LEFT },
     { "contains", 2, OP_KIND_INFIX , OP_ASSOC_LEFT },
+    { "startswith", 2, OP_KIND_INFIX , OP_ASSOC_LEFT },
+    { "endswith", 2, OP_KIND_INFIX , OP_ASSOC_LEFT },
 
     { ""        , 1, OP_KIND_INFIX , OP_ASSOC_LEFT },
     { "=="      , 1, OP_KIND_INFIX , OP_ASSOC_LEFT },

src/filter/scanner.c

@@ -75,7 +75,8 @@ const struct {
 // Strings that are treated as symbols
 const char *symbols[] = {
     "~", "not", "*", "/", "+", "-", "|", "&", "^", "%",
-    "and", "or", "in", "contains", "exists", "[", "]", "(", ")", ",",
+    "and", "or", "in", "contains", "startswith", "endswith", "exists",
+    "[", "]", "(", ")", ",",
     "<", ">", "==", "!=", ">=", "<=", "<<", ">>",
     "in", "out", "ingress", "egress", "src", "dst"
 };