1 files changed, 317 insertions, 0 deletions
diff --git a/lib/isccc/sexpr.c b/lib/isccc/sexpr.c
new file mode 100644
index 0000000..62c80c4
--- /dev/null
+++ b/lib/isccc/sexpr.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0 AND ISC
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Copyright (C) 2001 Nominum, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <isc/assertions.h>
+#include <isc/print.h>
+
+#include <isccc/sexpr.h>
+#include <isccc/util.h>
+
+static isccc_sexpr_t sexpr_t = { ISCCC_SEXPRTYPE_T, { NULL } };
+
+#define CAR(s) (s)->value.as_dottedpair.car
+#define CDR(s) (s)->value.as_dottedpair.cdr
+
+isccc_sexpr_t *
+isccc_sexpr_cons(isccc_sexpr_t *car, isccc_sexpr_t *cdr) {
+	isccc_sexpr_t *sexpr;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_DOTTEDPAIR;
+	CAR(sexpr) = car;
+	CDR(sexpr) = cdr;
+
+	return (sexpr);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_tconst(void) {
+	return (&sexpr_t);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_fromstring(const char *str) {
+	isccc_sexpr_t *sexpr;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_STRING;
+	sexpr->value.as_string = strdup(str);
+	if (sexpr->value.as_string == NULL) {
+		free(sexpr);
+		return (NULL);
+	}
+
+	return (sexpr);
+}
+
+isccc_sexpr_t *
+isccc_sexpr_frombinary(const isccc_region_t *region) {
+	isccc_sexpr_t *sexpr;
+	unsigned int region_size;
+
+	sexpr = malloc(sizeof(*sexpr));
+	if (sexpr == NULL) {
+		return (NULL);
+	}
+	sexpr->type = ISCCC_SEXPRTYPE_BINARY;
+	region_size = REGION_SIZE(*region);
+	/*
+	 * We add an extra byte when we malloc so we can NUL terminate
+	 * the binary data.  This allows the caller to use it as a C
+	 * string.  It's up to the caller to ensure this is safe.  We don't
+	 * add 1 to the length of the binary region, because the NUL is
+	 * not part of the binary data.
+	 */
+	sexpr->value.as_region.rstart = malloc(region_size + 1);
+	if (sexpr->value.as_region.rstart == NULL) {
+		free(sexpr);
+		return (NULL);
+	}
+	sexpr->value.as_region.rend = sexpr->value.as_region.rstart +
+				      region_size;
+	memmove(sexpr->value.as_region.rstart, region->rstart, region_size);
+	/*
+	 * NUL terminate.
+	 */
+	sexpr->value.as_region.rstart[region_size] = '\0';
+
+	return (sexpr);
+}
+
+void
+isccc_sexpr_free(isccc_sexpr_t **sexprp) {
+	isccc_sexpr_t *sexpr;
+	isccc_sexpr_t *item;
+
+	sexpr = *sexprp;
+	*sexprp = NULL;
+	if (sexpr == NULL) {
+		return;
+	}
+	switch (sexpr->type) {
+	case ISCCC_SEXPRTYPE_STRING:
+		free(sexpr->value.as_string);
+		break;
+	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
+		item = CAR(sexpr);
+		if (item != NULL) {
+			isccc_sexpr_free(&item);
+		}
+		item = CDR(sexpr);
+		if (item != NULL) {
+			isccc_sexpr_free(&item);
+		}
+		break;
+	case ISCCC_SEXPRTYPE_BINARY:
+		free(sexpr->value.as_region.rstart);
+		break;
+	}
+	free(sexpr);
+}
+
+static bool
+printable(isccc_region_t *r) {
+	unsigned char *curr;
+
+	curr = r->rstart;
+	while (curr != r->rend) {
+		if (!isprint(*curr)) {
+			return (false);
+		}
+		curr++;
+	}
+
+	return (true);
+}
+
+void
+isccc_sexpr_print(isccc_sexpr_t *sexpr, FILE *stream) {
+	isccc_sexpr_t *cdr;
+	unsigned int size, i;
+	unsigned char *curr;
+
+	if (sexpr == NULL) {
+		fprintf(stream, "nil");
+		return;
+	}
+
+	switch (sexpr->type) {
+	case ISCCC_SEXPRTYPE_T:
+		fprintf(stream, "t");
+		break;
+	case ISCCC_SEXPRTYPE_STRING:
+		fprintf(stream, "\"%s\"", sexpr->value.as_string);
+		break;
+	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
+		fprintf(stream, "(");
+		do {
+			isccc_sexpr_print(CAR(sexpr), stream);
+			cdr = CDR(sexpr);
+			if (cdr != NULL) {
+				fprintf(stream, " ");
+				if (cdr->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
+					fprintf(stream, ". ");
+					isccc_sexpr_print(cdr, stream);
+					cdr = NULL;
+				}
+			}
+			sexpr = cdr;
+		} while (sexpr != NULL);
+		fprintf(stream, ")");
+		break;
+	case ISCCC_SEXPRTYPE_BINARY:
+		size = REGION_SIZE(sexpr->value.as_region);
+		curr = sexpr->value.as_region.rstart;
+		if (printable(&sexpr->value.as_region)) {
+			fprintf(stream, "'%.*s'", (int)size, curr);
+		} else {
+			fprintf(stream, "0x");
+			for (i = 0; i < size; i++) {
+				fprintf(stream, "%02x", *curr++);
+			}
+		}
+		break;
+	default:
+		UNREACHABLE();
+	}
+}
+
+isccc_sexpr_t *
+isccc_sexpr_car(isccc_sexpr_t *list) {
+	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	return (CAR(list));
+}
+
+isccc_sexpr_t *
+isccc_sexpr_cdr(isccc_sexpr_t *list) {
+	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	return (CDR(list));
+}
+
+void
+isccc_sexpr_setcar(isccc_sexpr_t *pair, isccc_sexpr_t *car) {
+	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	CAR(pair) = car;
+}
+
+void
+isccc_sexpr_setcdr(isccc_sexpr_t *pair, isccc_sexpr_t *cdr) {
+	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	CDR(pair) = cdr;
+}
+
+isccc_sexpr_t *
+isccc_sexpr_addtolist(isccc_sexpr_t **l1p, isccc_sexpr_t *l2) {
+	isccc_sexpr_t *last, *elt, *l1;
+
+	REQUIRE(l1p != NULL);
+	l1 = *l1p;
+	REQUIRE(l1 == NULL || l1->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
+
+	elt = isccc_sexpr_cons(l2, NULL);
+	if (elt == NULL) {
+		return (NULL);
+	}
+	if (l1 == NULL) {
+		*l1p = elt;
+		return (elt);
+	}
+	for (last = l1; CDR(last) != NULL; last = CDR(last)) {
+		/* Nothing */
+	}
+	CDR(last) = elt;
+
+	return (elt);
+}
+
+bool
+isccc_sexpr_listp(isccc_sexpr_t *sexpr) {
+	if (sexpr == NULL || sexpr->type == ISCCC_SEXPRTYPE_DOTTEDPAIR) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_emptyp(isccc_sexpr_t *sexpr) {
+	if (sexpr == NULL) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_stringp(isccc_sexpr_t *sexpr) {
+	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_STRING) {
+		return (true);
+	}
+	return (false);
+}
+
+bool
+isccc_sexpr_binaryp(isccc_sexpr_t *sexpr) {
+	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY) {
+		return (true);
+	}
+	return (false);
+}
+
+char *
+isccc_sexpr_tostring(isccc_sexpr_t *sexpr) {
+	REQUIRE(sexpr != NULL && (sexpr->type == ISCCC_SEXPRTYPE_STRING ||
+				  sexpr->type == ISCCC_SEXPRTYPE_BINARY));
+
+	if (sexpr->type == ISCCC_SEXPRTYPE_BINARY) {
+		return ((char *)sexpr->value.as_region.rstart);
+	}
+	return (sexpr->value.as_string);
+}
+
+isccc_region_t *
+isccc_sexpr_tobinary(isccc_sexpr_t *sexpr) {
+	REQUIRE(sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY);
+	return (&sexpr->value.as_region);
+}