1 files changed, 461 insertions, 0 deletions
diff --git a/src/global/compat_level.c b/src/global/compat_level.c
new file mode 100644
index 0000000..7430878
--- /dev/null
+++ b/src/global/compat_level.c
@@ -0,0 +1,461 @@
+/*++
+/* NAME
+/*	compat_level 3
+/* SUMMARY
+/*	compatibility_level support
+/* SYNOPSIS
+/*	#include <compat_level.h>
+/*
+/*	void compat_level_relop_register(void)
+/*
+/*	long	compat_level_from_string(
+/*	const char *str,
+/*	void	PRINTFLIKE(1, 2) (*msg_fn)(const char *,...))
+/*
+/*	long	compat_level_from_numbers(
+/*	long	major,
+/*	long	minor,
+/*	long	patch,
+/*	void	PRINTFLIKE(1, 2) (*msg_fn)(const char *,...))
+/*
+/*	const char *compat_level_to_string(
+/*	long	compat_level,
+/*	void	PRINTFLIKE(1, 2) (*msg_fn)(const char *,...))
+/* AUXULIARY FUNCTIONS
+/*	long	compat_level_from_major_minor(
+/*	long	major,
+/*	long	minor,
+/*	void	PRINTFLIKE(1, 2) (*msg_fn)(const char *,...))
+/*
+/*	long	compat_level_from_major(
+/*	long	major,
+/*	void	PRINTFLIKE(1, 2) (*msg_fn)(const char *,...))
+/* DESCRIPTION
+/*	This module supports compatibility level syntax with
+/*	"major.minor.patch" but will also accept the shorter forms
+/*	"major.minor" and "major" (missing members default to zero).
+/*	Compatibility levels with multiple numbers cannot be compared
+/*	as strings or as floating-point numbers (for example, "3.10"
+/*	would be smaller than "3.9").
+/*
+/*	The major number can range from [0..2047] inclusive (11
+/*	bits) or more, while the minor and patch numbers can range
+/*	from [0..1023] inclusive (10 bits).
+/*
+/*	compat_level_from_string() converts a compatibility level
+/*	from string form to numerical form for easy comparison.
+/*	Valid input results in a non-negative result. In case of
+/*	error, compat_level_from_string() reports the problem with
+/*	the provided function, and returns -1 if that function does
+/*	not terminate execution.
+/*
+/*	compat_level_from_numbers() creates an internal-form
+/*	compatibility level from distinct numbers. Valid input
+/*	results in a non-negative result. In case of error,
+/*	compat_level_from_numbers() reports the problem with the
+/*	provided function, and returns -1 if that function does not
+/*	terminate execution.
+/*
+/*	The functions compat_level_from_major_minor() and
+/*	compat_level_from_major() are helpers that default the missing
+/*	information to zeroes.
+/*
+/*	compat_level_to_string() converts a compatibility level
+/*	from numerical form to canonical string form. Valid input
+/*	results in a non-null result. In case of error,
+/*	compat_level_to_string() reports the problem with the
+/*	provided function, and returns a null pointer if that
+/*	function does not terminate execution.
+/*
+/*	compat_level_relop_register() registers a mac_expand() callback
+/*	that registers operators such as <=level, >level, that compare
+/*	compatibility levels. This function should be called before
+/*	loading parameter settings from main.cf.
+/* DIAGNOSTICS
+/*	info, .., panic: bad compatibility_level syntax.
+/* BUGS
+/*	The patch and minor fields range from 0..1023 (10 bits) while
+/*	the major field ranges from 0..COMPAT_MAJOR_SHIFT47 or more
+/*	(11 bits or more).
+/*
+/*	This would be a great use case for functions returning
+/*	StatusOr<compat_level_t> or StatusOr<string>, but is it a bit
+/*	late for a port to C++.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+ /*
+  * System library.
+  */
+#include <sys_defs.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+
+ /*
+  * Utility library.
+  */
+#include <mac_expand.h>
+#include <msg.h>
+#include <sane_strtol.h>
+
+ /*
+  * For easy comparison we convert a three-number compatibility level into
+  * just one number, using different bit ranges for the major version, minor
+  * version, and patch level.
+  * 
+  * We use long integers because standard C guarantees that long has at last 32
+  * bits instead of int which may have only 16 bits (though it is unlikely
+  * that Postfix would run on such systems). That gives us 11 or more bits
+  * for the major version, and 10 bits for minor the version and patchlevel.
+  * 
+  * Below are all the encoding details in one place. This is easier to verify
+  * than wading through code.
+  */
+#define COMPAT_MAJOR_SHIFT \
+	(COMPAT_MINOR_SHIFT + COMPAT_MINOR_WIDTH)
+
+#define COMPAT_MINOR_SHIFT	COMPAT_PATCH_WIDTH
+#define COMPAT_MINOR_BITS	0x3ff
+#define COMPAT_MINOR_WIDTH	10
+
+#define COMPAT_PATCH_BITS	0x3ff
+#define COMPAT_PATCH_WIDTH	10
+
+#define GOOD_MAJOR(m)	((m) >= 0 && (m) <= (LONG_MAX >> COMPAT_MAJOR_SHIFT))
+#define GOOD_MINOR(m)	((m) >= 0 && (m) <= COMPAT_MINOR_BITS)
+#define GOOD_PATCH(p)	((p) >= 0 && (p) <= COMPAT_PATCH_BITS)
+
+#define ENCODE_MAJOR(m)	((m) << COMPAT_MAJOR_SHIFT)
+#define ENCODE_MINOR(m)	((m) << COMPAT_MINOR_SHIFT)
+#define ENCODE_PATCH(p)	(p)
+
+#define DECODE_MAJOR(l)	((l) >> COMPAT_MAJOR_SHIFT)
+#define DECODE_MINOR(l)	(((l) >> COMPAT_MINOR_SHIFT) & COMPAT_MINOR_BITS)
+#define DECODE_PATCH(l)	((l) & COMPAT_PATCH_BITS)
+
+ /*
+  * Global library.
+  */
+#include <compat_level.h>
+
+/* compat_level_from_string - convert major[.minor] to comparable type */
+
+long    compat_level_from_string(const char *str,
+		         void PRINTFLIKE(1, 2) (*msg_fn) (const char *,...))
+{
+    long    major, minor, patch, res = 0;
+    const char *start;
+    char   *remainder;
+
+    start = str;
+    major = sane_strtol(start, &remainder, 10);
+    if (start < remainder && (*remainder == 0 || *remainder == '.')
+	&& errno != ERANGE && GOOD_MAJOR(major)) {
+	res = ENCODE_MAJOR(major);
+	if (*remainder == 0)
+	    return res;
+	start = remainder + 1;
+	minor = sane_strtol(start, &remainder, 10);
+	if (start < remainder && (*remainder == 0 || *remainder == '.')
+	    && errno != ERANGE && GOOD_MINOR(minor)) {
+	    res |= ENCODE_MINOR(minor);
+	    if (*remainder == 0)
+		return (res);
+	    start = remainder + 1;
+	    patch = sane_strtol(start, &remainder, 10);
+	    if (start < remainder && *remainder == 0 && errno != ERANGE
+		&& GOOD_PATCH(patch)) {
+		return (res | ENCODE_PATCH(patch));
+	    }
+	}
+    }
+    msg_fn("malformed compatibility level syntax: \"%s\"", str);
+    return (-1);
+}
+
+/* compat_level_from_numbers - internal form from numbers */
+
+long    compat_level_from_numbers(long major, long minor, long patch,
+		         void PRINTFLIKE(1, 2) (*msg_fn) (const char *,...))
+{
+    const char myname[] = "compat_level_from_numbers";
+
+    /*
+     * Sanity checks.
+     */
+    if (!GOOD_MAJOR(major)) {
+	msg_fn("%s: bad major version: %ld", myname, major);
+	return (-1);
+    }
+    if (!GOOD_MINOR(minor)) {
+	msg_fn("%s: bad minor version: %ld", myname, minor);
+	return (-1);
+    }
+    if (!GOOD_PATCH(patch)) {
+	msg_fn("%s: bad patch level: %ld", myname, patch);
+	return (-1);
+    }
+
+    /*
+     * Conversion.
+     */
+    return (ENCODE_MAJOR(major) | ENCODE_MINOR(minor) | ENCODE_PATCH(patch));
+}
+
+/* compat_level_to_string - pretty-print a compatibility level */
+
+const char *compat_level_to_string(long compat_level,
+		         void PRINTFLIKE(1, 2) (*msg_fn) (const char *,...))
+{
+    const char myname[] = "compat_level_to_string";
+    static VSTRING *buf;
+    long    major;
+    long    minor;
+    long    patch;
+
+    /*
+     * Sanity check.
+     */
+    if (compat_level < 0) {
+        msg_fn("%s: bad compatibility level: %ld", myname, compat_level);
+        return (0);
+    }
+
+    /*
+     * Compatibility levels 0..2 have no minor or patch level.
+     */
+    if (buf == 0)
+        buf = vstring_alloc(10);
+    major = DECODE_MAJOR(compat_level);
+    if (!GOOD_MAJOR(major)) {
+        msg_fn("%s: bad compatibility major level: %ld", myname, compat_level);
+        return (0);
+    }
+    vstring_sprintf(buf, "%ld", major);
+    if (major > 2) {
+
+        /*
+         * Expect that major.minor will be common.
+         */
+        minor = DECODE_MINOR(compat_level);
+        vstring_sprintf_append(buf, ".%ld", minor);
+
+        /*
+         * Expect that major.minor.patch will be rare.
+         */
+        patch = DECODE_PATCH(compat_level);
+        if (patch)
+            vstring_sprintf_append(buf, ".%ld", patch);
+    }
+    return (vstring_str(buf));
+}
+
+/* compat_relop_eval - mac_expand callback */
+
+static MAC_EXP_OP_RES compat_relop_eval(const char *left_str, int relop,
+					        const char *rite_str)
+{
+    const char myname[] = "compat_relop_eval";
+    long    left_val, rite_val;
+
+    /*
+     * Negative result means error.
+     */
+    if ((left_val = compat_level_from_string(left_str, msg_warn)) < 0
+	|| (rite_val = compat_level_from_string(rite_str, msg_warn)) < 0)
+	return (MAC_EXP_OP_RES_ERROR);
+
+    /*
+     * Valid result. The difference between non-negative numbers will no
+     * overflow.
+     */
+    long    delta = left_val - rite_val;
+
+    switch (relop) {
+    case MAC_EXP_OP_TOK_EQ:
+	return (mac_exp_op_res_bool[delta == 0]);
+    case MAC_EXP_OP_TOK_NE:
+	return (mac_exp_op_res_bool[delta != 0]);
+    case MAC_EXP_OP_TOK_LT:
+	return (mac_exp_op_res_bool[delta < 0]);
+    case MAC_EXP_OP_TOK_LE:
+	return (mac_exp_op_res_bool[delta <= 0]);
+    case MAC_EXP_OP_TOK_GE:
+	return (mac_exp_op_res_bool[delta >= 0]);
+    case MAC_EXP_OP_TOK_GT:
+	return (mac_exp_op_res_bool[delta > 0]);
+    default:
+	msg_panic("%s: unknown operator: %d",
+		  myname, relop);
+    }
+}
+
+/* compat_level_register - register comparison operators */
+
+void    compat_level_relop_register(void)
+{
+    int     compat_level_relops[] = {
+	MAC_EXP_OP_TOK_EQ, MAC_EXP_OP_TOK_NE,
+	MAC_EXP_OP_TOK_GT, MAC_EXP_OP_TOK_GE,
+	MAC_EXP_OP_TOK_LT, MAC_EXP_OP_TOK_LE,
+	0,
+    };
+    static int register_done;
+
+    if (register_done++ == 0)
+	mac_expand_add_relop(compat_level_relops, "level", compat_relop_eval);
+}
+
+#ifdef TEST
+#include <unistd.h>
+
+#include <htable.h>
+#include <mymalloc.h>
+#include <stringops.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <vstring_vstream.h>
+
+static const char *lookup(const char *name, int unused_mode, void *context)
+{
+    HTABLE *table = (HTABLE *) context;
+
+    return (htable_find(table, name));
+}
+
+static void test_expand(void)
+{
+    VSTRING *buf = vstring_alloc(100);
+    VSTRING *result = vstring_alloc(100);
+    char   *cp;
+    char   *name;
+    char   *value;
+    HTABLE *table;
+    int     stat;
+
+    /*
+     * Add relops that compare string lengths instead of content.
+     */
+    compat_level_relop_register();
+
+    /*
+     * Loop over the inputs.
+     */
+    while (!vstream_feof(VSTREAM_IN)) {
+
+	table = htable_create(0);
+
+	/*
+	 * Read a block of definitions, terminated with an empty line.
+	 */
+	while (vstring_get_nonl(buf, VSTREAM_IN) != VSTREAM_EOF) {
+	    vstream_printf("<< %s\n", vstring_str(buf));
+	    vstream_fflush(VSTREAM_OUT);
+	    if (VSTRING_LEN(buf) == 0)
+		break;
+	    cp = vstring_str(buf);
+	    name = mystrtok(&cp, CHARS_SPACE "=");
+	    value = mystrtok(&cp, CHARS_SPACE "=");
+	    htable_enter(table, name, value ? mystrdup(value) : 0);
+	}
+
+	/*
+	 * Read a block of patterns, terminated with an empty line or EOF.
+	 */
+	while (vstring_get_nonl(buf, VSTREAM_IN) != VSTREAM_EOF) {
+	    vstream_printf("<< %s\n", vstring_str(buf));
+	    vstream_fflush(VSTREAM_OUT);
+	    if (VSTRING_LEN(buf) == 0)
+		break;
+	    VSTRING_RESET(result);
+	    stat = mac_expand(result, vstring_str(buf), MAC_EXP_FLAG_NONE,
+			      (char *) 0, lookup, (void *) table);
+	    vstream_printf("stat=%d result=%s\n", stat, vstring_str(result));
+	    vstream_fflush(VSTREAM_OUT);
+	}
+	htable_free(table, myfree);
+	vstream_printf("\n");
+    }
+
+    /*
+     * Clean up.
+     */
+    vstring_free(buf);
+    vstring_free(result);
+}
+
+static void test_convert(void)
+{
+    VSTRING *buf = vstring_alloc(100);
+    long    compat_level;
+    const char *as_string;
+
+    /*
+     * Read compatibility level.
+     */
+    while (vstring_get_nonl(buf, VSTREAM_IN) != VSTREAM_EOF) {
+	if ((compat_level = compat_level_from_string(vstring_str(buf),
+						     msg_warn)) < 0)
+	    continue;
+	msg_info("%s -> 0x%lx", vstring_str(buf), compat_level);
+	errno = ERANGE;
+	if ((as_string = compat_level_to_string(compat_level,
+						msg_warn)) == 0)
+	    continue;
+	msg_info("0x%lx->%s", compat_level, as_string);
+    }
+    vstring_free(buf);
+}
+
+static NORETURN usage(char **argv)
+{
+    msg_fatal("usage: %s option\n-c (convert)\n-c (expand)", argv[0]);
+}
+
+int     main(int argc, char **argv)
+{
+    int     ch;
+    int     mode = 0;
+
+#define MODE_EXPAND	(1<<0)
+#define MODE_CONVERT	(1<<1)
+
+    while ((ch = GETOPT(argc, argv, "cx")) > 0) {
+	switch (ch) {
+	case 'c':
+	    mode |= MODE_CONVERT;
+	    break;
+	case 'v':
+	    msg_verbose++;
+	    break;
+	case 'x':
+	    mode |= MODE_EXPAND;
+	    break;
+	default:
+	    usage(argv);
+	}
+    }
+    switch (mode) {
+    case MODE_CONVERT:
+	test_convert();
+	break;
+    case MODE_EXPAND:
+	test_expand();
+	break;
+    default:
+	usage(argv);
+    }
+    exit(0);
+}
+
+#endif