blobmsg_json: prefer snprintf usage

Better safe than sorry and while at it prefer use of PRId16 and PRId32
formatting constants as well.

Reviewed-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Petr Štetiar <ynezz@true.cz>

3 files changed, 50 insertions, 30 deletions

diff --git a/blobmsg_json.c b/blobmsg_json.c
index aedc2da..dce81e9 100644
--- a/blobmsg_json.c
+++ b/blobmsg_json.c
@@ -208,7 +208,7 @@ static void blobmsg_format_string(struct strbuf *s, const char *str)
 		buf[1] = escape;
 
 		if (escape == 'u') {
-			sprintf(buf + 4, "%02x", (unsigned char) *p);
+			snprintf(buf + 4, sizeof(buf) - 4, "%02x", (unsigned char) *p);
 			len = 6;
 		} else {
 			len = 2;
@@ -225,7 +225,7 @@ static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, i
 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool without_name, bool head)
 {
 	const char *data_str;
-	char buf[32];
+	char buf[317];
 	void *data;
 	int len;
 
@@ -249,22 +249,22 @@ static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, boo
 	data_str = buf;
 	switch(blob_id(attr)) {
 	case BLOBMSG_TYPE_UNSPEC:
-		sprintf(buf, "null");
+		snprintf(buf, sizeof(buf), "null");
 		break;
 	case BLOBMSG_TYPE_BOOL:
-		sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
+		snprintf(buf, sizeof(buf), "%s", *(uint8_t *)data ? "true" : "false");
 		break;
 	case BLOBMSG_TYPE_INT16:
-		sprintf(buf, "%d", (int16_t) be16_to_cpu(*(uint16_t *)data));
+		snprintf(buf, sizeof(buf), "%" PRId16, (int16_t) be16_to_cpu(*(uint16_t *)data));
 		break;
 	case BLOBMSG_TYPE_INT32:
-		sprintf(buf, "%d", (int32_t) be32_to_cpu(*(uint32_t *)data));
+		snprintf(buf, sizeof(buf), "%" PRId32, (int32_t) be32_to_cpu(*(uint32_t *)data));
 		break;
 	case BLOBMSG_TYPE_INT64:
-		sprintf(buf, "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
+		snprintf(buf, sizeof(buf), "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 		break;
 	case BLOBMSG_TYPE_DOUBLE:
-		sprintf(buf, "%lf", blobmsg_get_double(attr));
+		snprintf(buf, sizeof(buf), "%lf", blobmsg_get_double(attr));
 		break;
 	case BLOBMSG_TYPE_STRING:
 		blobmsg_format_string(s, data);
diff --git a/tests/cram/test_blobmsg.t b/tests/cram/test_blobmsg.t
index 74ad326..0c192c5 100644
--- a/tests/cram/test_blobmsg.t
+++ b/tests/cram/test_blobmsg.t
@@ -16,10 +16,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 100 (i8) (esc)
   \tmoo-min : -128 (i8) (esc)
@@ -33,7 +35,7 @@ check that blobmsg is producing expected results:
   \tworld : 2 (str) (esc)
   }
   
-  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"double":133.700000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,133.700000]}
+  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"dbl-min":0.000000,"dbl-max":179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,0.000000,179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000]}
   
   [*] blobmsg from json:
   Message: Hello, world!
@@ -48,10 +50,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 1 (i8) (esc)
   \tmoo-min : 1 (i8) (esc)
@@ -79,10 +83,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 100 (i8) (esc)
   \tmoo-min : -128 (i8) (esc)
@@ -96,7 +102,7 @@ check that blobmsg is producing expected results:
   \tworld : 2 (str) (esc)
   }
   
-  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"double":133.700000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,133.700000]}
+  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"dbl-min":0.000000,"dbl-max":179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,0.000000,179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000]}
   
   [*] blobmsg from json:
   Message: Hello, world!
@@ -111,10 +117,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 1 (i8) (esc)
   \tmoo-min : 1 (i8) (esc)
@@ -142,10 +150,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 100 (i8) (esc)
   \tmoo-min : -128 (i8) (esc)
@@ -159,7 +169,7 @@ check that blobmsg is producing expected results:
   \tworld : 2 (str) (esc)
   }
   
-  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"double":133.700000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,133.700000]}
+  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"dbl-min":0.000000,"dbl-max":179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,0.000000,179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000]}
   
   [*] blobmsg from json:
   Message: Hello, world!
@@ -174,10 +184,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 1 (i8) (esc)
   \tmoo-min : 1 (i8) (esc)
@@ -205,10 +217,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 100 (i8) (esc)
   \tmoo-min : -128 (i8) (esc)
@@ -222,7 +236,7 @@ check that blobmsg is producing expected results:
   \tworld : 2 (str) (esc)
   }
   
-  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"double":133.700000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,133.700000]}
+  [*] blobmsg to json: {"message":"Hello, world!","testdata":{"dbl-min":0.000000,"dbl-max":179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000,"foo":false,"poo":true,"moo-min":true,"moo-max":true,"bar-min":-32768,"bar-max":32767,"baz-min":-2147483648,"baz-max":2147483647,"taz-min":-9223372036854775808,"taz-max":9223372036854775807,"world":"2"},"list":[false,true,true,true,-32768,32767,-2147483648,2147483647,-9223372036854775808,9223372036854775807,0.000000,179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000]}
   
   [*] blobmsg from json:
   Message: Hello, world!
@@ -237,10 +251,12 @@ check that blobmsg is producing expected results:
   2147483647 (i32)
   -9223372036854775808 (i64)
   9223372036854775807 (i64)
-  133.700000 (dbl)
+  0.000000 (dbl)
+  179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl)
   }
   Testdata: {
-  \tdouble : 133.700000 (dbl) (esc)
+  \tdbl-min : 0.000000 (dbl) (esc)
+  \tdbl-max : 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000 (dbl) (esc)
   \tfoo : 0 (i8) (esc)
   \tpoo : 1 (i8) (esc)
   \tmoo-min : 1 (i8) (esc)
diff --git a/tests/test-blobmsg.c b/tests/test-blobmsg.c
index 58b0bc4..2224853 100644
--- a/tests/test-blobmsg.c
+++ b/tests/test-blobmsg.c
@@ -1,4 +1,6 @@
 #include <stdio.h>
+#include <float.h>
+#include <limits.h>
 #include <stdint.h>
 #include <inttypes.h>
 
@@ -117,7 +119,8 @@ fill_message(struct blob_buf *buf)
 	blobmsg_add_string(buf, "message", "Hello, world!");
 
 	tbl = blobmsg_open_table(buf, "testdata");
-	blobmsg_add_double(buf, "double", 1.337e2);
+	blobmsg_add_double(buf, "dbl-min", DBL_MIN);
+	blobmsg_add_double(buf, "dbl-max", DBL_MAX);
 	blobmsg_add_u8(buf, "foo", 0);
 	blobmsg_add_u8(buf, "poo", 100);
 	blobmsg_add_u8(buf, "moo-min", INT8_MIN);
@@ -142,7 +145,8 @@ fill_message(struct blob_buf *buf)
 	blobmsg_add_u32(buf, NULL, INT32_MAX);
 	blobmsg_add_u64(buf, NULL, INT64_MIN);
 	blobmsg_add_u64(buf, NULL, INT64_MAX);
-	blobmsg_add_double(buf, "double", 1.337e2);
+	blobmsg_add_double(buf, NULL, DBL_MIN);
+	blobmsg_add_double(buf, NULL, DBL_MAX);
 	blobmsg_close_table(buf, tbl);
 }