[PATCH 10/10] setexpr: Add support for strings

1 Nov 2020

Add support for dealing with string operands, including reading a string
from memory into an environment variable and concatenating two strings.
Signed-off-by: Simon Glass sjg@chromium.org
---
cmd/setexpr.c      | 82 +++++++++++++++++++++++++++++++++++++++----
 test/cmd/setexpr.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 161 insertions(+), 7 deletions(-)

diff --git a/cmd/setexpr.c b/cmd/setexpr.c
index 8a3654505da..e828be39700 100644
--- a/cmd/setexpr.c
+++ b/cmd/setexpr.c
@@ -13,15 +13,21 @@
 #include <command.h>
 #include <env.h>
 #include <log.h>
+#include <malloc.h>
 #include <mapmem.h>
+#include <linux/sizes.h>
/**
  * struct expr_arg: Holds an argument to an expression
  *
  * @ival: Integer value (if width is not CMD_DATA_SIZE_STR)
+ * @sval: String value (if width is CMD_DATA_SIZE_STR)
  */
 struct expr_arg {
-	ulong ival;
+	union {
+		ulong ival;
+		char *sval;
+	};
 };
static int get_arg(char *s, int w, struct expr_arg *argp)
@@ -36,6 +42,8 @@ static int get_arg(char *s, int w, struct expr_arg *argp)
    	ulong *p;
    	ulong addr;
    	ulong val;
+		int len;
+		char *str;
addr = simple_strtoul(&s[1], NULL, 16);
    	switch (w) {
@@ -51,6 +59,21 @@ static int get_arg(char *s, int w, struct expr_arg *argp)
    		unmap_sysmem(p);
    		arg.ival = val;
    		break;
+		case CMD_DATA_SIZE_STR:
+			p = map_sysmem(addr, SZ_64K);
+
+			/* Maximum string length of 64KB plus terminator */
+			len = strnlen((char *)p, SZ_64K) + 1;
+			str = malloc(len);
+			if (!str) {
+				printf("Out of memory\n");
+				return -ENOMEM;
+			}
+			memcpy(str, p, len);
+			str[len - 1] = '\0';
+			unmap_sysmem(p);
+			arg.sval = str;
+			break;
    	case 4:
    		p = map_sysmem(addr, sizeof(u32));
    		val = *(u32 *)p;
@@ -65,6 +88,8 @@ static int get_arg(char *s, int w, struct expr_arg *argp)
    		break;
    	}
    } else {
+		if (w == CMD_DATA_SIZE_STR)
+			return -EINVAL;
    	arg.ival = simple_strtoul(s, NULL, 16);
    }
    *argp = arg;
@@ -341,6 +366,7 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
 {
    struct expr_arg aval, bval;
    ulong value;
+	int ret = 0;
    int w;
/*
@@ -361,8 +387,16 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
    	return CMD_RET_FAILURE;
/* plain assignment: "setexpr name value" */
-	if (argc == 3)
-		return env_set_hex(argv[1], aval.ival);
+	if (argc == 3) {
+		if (w == CMD_DATA_SIZE_STR) {
+			ret = env_set(argv[1], aval.sval);
+			free(aval.sval);
+		} else {
+			ret = env_set_hex(argv[1], aval.ival);
+		}
+
+		return ret;
+	}
/* 5 or 6 args (6 args only with [g]sub) */
 #ifdef CONFIG_REGEX
@@ -384,10 +418,38 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
    if (strlen(argv[3]) != 1)
    	return CMD_RET_USAGE;
-	if (get_arg(argv[4], w, &bval))
+	if (get_arg(argv[4], w, &bval)) {
+		if (w == CMD_DATA_SIZE_STR)
+			free(aval.sval);
    	return CMD_RET_FAILURE;
+	}
+
+	if (w == CMD_DATA_SIZE_STR) {
+		int len;
+		char *str;
-	if (w != CMD_DATA_SIZE_STR) {
+		switch (argv[3][0]) {
+		case '+':
+			len = strlen(aval.sval) + strlen(bval.sval) + 1;
+			str = malloc(len);
+			if (!str) {
+				printf("Out of memory\n");
+				ret = CMD_RET_FAILURE;
+			} else {
+				/* These were copied out and checked earlier */
+				strcpy(str, aval.sval);
+				strcat(str, bval.sval);
+				ret = env_set(argv[1], str);
+				if (ret)
+					printf("Could not set var\n");
+				free(str);
+			}
+			break;
+		default:
+			printf("invalid op\n");
+			ret = 1;
+		}
+	} else {
    	ulong a = aval.ival;
    	ulong b = bval.ival;
@@ -424,15 +486,21 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
    	env_set_hex(argv[1], value);
    }
-	return 0;
+	if (w == CMD_DATA_SIZE_STR) {
+		free(aval.sval);
+		free(bval.sval);
+	}
+
+	return ret;
 }
U_BOOT_CMD(
    setexpr, 6, 0, do_setexpr,
    "set environment variable as the result of eval expression",
-	"[.b, .w, .l] name [*]value1 <op> [*]value2\n"
+	"[.b, .w, .l, .s] name [*]value1 <op> [*]value2\n"
    "    - set environment variable 'name' to the result of the evaluated\n"
    "      expression specified by <op>.  <op> can be &, |, ^, +, -, *, /, %\n"
+	"      (for strings only + is supported)\n"
    "      size argument is only meaningful if value1 and/or value2 are\n"
    "      memory addresses (*)\n"
    "setexpr[.b, .w, .l] name [*]value\n"
diff --git a/test/cmd/setexpr.c b/test/cmd/setexpr.c
index 2a897efd9bd..fd6d869c0ed 100644
--- a/test/cmd/setexpr.c
+++ b/test/cmd/setexpr.c
@@ -287,6 +287,92 @@ static int setexpr_test_backref(struct unit_test_state *uts)
 }
 SETEXPR_TEST(setexpr_test_backref, UT_TESTF_CONSOLE_REC);
+/* Test 'setexpr' command with setting strings */
+static int setexpr_test_str(struct unit_test_state *uts)
+{
+	ulong start_mem;
+	char *buf;
+
+	buf = map_sysmem(0, BUF_SIZE);
+	memset(buf, '\xff', BUF_SIZE);
+
+	/*
+	 * Set 'fred' to the same length as we expect to get below, to avoid a
+	 * new allocation in 'setexpr'. That way we can check for memory leaks.
+	 */
+	ut_assertok(env_set("fred", "x"));
+	start_mem = ut_check_free();
+	strcpy(buf, "hello");
+	ut_asserteq(1, run_command("setexpr.s fred 0", 0));
+	ut_assertok(ut_check_delta(start_mem));
+
+	start_mem = ut_check_free();
+	ut_assertok(env_set("fred", "12345"));
+	ut_assertok(run_command("setexpr.s fred *0", 0));
+	ut_asserteq_str("hello", env_get("fred"));
+	ut_assertok(ut_check_delta(start_mem));
+
+	unmap_sysmem(buf);
+
+	return 0;
+}
+SETEXPR_TEST(setexpr_test_str, UT_TESTF_CONSOLE_REC);
+
+
+/* Test 'setexpr' command with concatenating strings */
+static int setexpr_test_str_oper(struct unit_test_state *uts)
+{
+	ulong start_mem;
+	char *buf;
+
+	buf = map_sysmem(0, BUF_SIZE);
+	memset(buf, '\xff', BUF_SIZE);
+	strcpy(buf, "hello");
+	strcpy(buf + 0x10, " there");
+
+	ut_assertok(console_record_reset_enable());
+	start_mem = ut_check_free();
+	ut_asserteq(1, run_command("setexpr.s fred *0 * *10", 0));
+	ut_assertok(ut_check_delta(start_mem));
+	ut_assert_nextline("invalid op");
+	ut_assert_console_end();
+
+	/*
+	 * Set 'fred' to the same length as we expect to get below, to avoid a
+	 * new allocation in 'setexpr'. That way we can check for memory leaks.
+	 */
+	ut_assertok(env_set("fred", "12345012345"));
+	start_mem = ut_check_free();
+	ut_assertok(run_command("setexpr.s fred *0 + *10", 0));
+	ut_asserteq_str("hello there", env_get("fred"));
+	ut_assertok(ut_check_delta(start_mem));
+
+	unmap_sysmem(buf);
+
+	return 0;
+}
+SETEXPR_TEST(setexpr_test_str_oper, UT_TESTF_CONSOLE_REC);
+
+/* Test 'setexpr' command with a string that is too long */
+static int setexpr_test_str_long(struct unit_test_state *uts)
+{
+	const int size = 128 << 10;  /* setexpr strings are a max of 64KB */
+	char *buf, *val;
+
+	buf = map_sysmem(0, size);
+	memset(buf, 'a', size);
+
+	/* String should be truncated to 64KB */
+	ut_assertok(run_command("setexpr.s fred *0", 0));
+	val = env_get("fred");
+	ut_asserteq(64 << 10, strlen(val));
+
+	unmap_sysmem(buf);
+
+	return 0;
+}
+SETEXPR_TEST(setexpr_test_str_long, UT_TESTF_CONSOLE_REC);
+
 int do_ut_setexpr(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
    struct unit_test *tests = ll_entry_start(struct unit_test,
-- 
2.29.1.341.ge80a0c044ae-goog


    