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authorNeels Hofmeyr <neels@hofmeyr.de>2018-12-05 21:02:36 +0100
committerHarald Welte <laforge@gnumonks.org>2018-12-10 17:06:30 +0000
commit7079e698481705c82c7aff58ea9c63469626af80 (patch)
tree4e9ba1b40828af8cbfe97a6ce7872bfc8cbc0c66
parentc01cff1a502b95ef6d5348e4b8bbfcf746b5d2e4 (diff)
add osmo_bcd2str()
Add a standalone bcd-to-string conversion function with generic parameters. Add a regression test in utils_test.c. So far there is no single universal implementation that converts a BCD to a string. I could only find gsm48_mi_to_string(), which also interprets surrounding bytes, MI type and TMSI as non-BCD value. The idea is to use this function from gsm48_mi_to_string() and similar implementations in subsequent commits. Root cause: in osmo-msc, I want to have an alternative MI-to-string function for composing an FSM name, which needs the BCD part of gsm48_mi_to_string() but not the TMSI part. Change-Id: I86b09d37ceef33331c1a56046a5443127d6c6be0
-rw-r--r--include/osmocom/core/utils.h2
-rw-r--r--src/utils.c41
-rw-r--r--tests/utils/utils_test.c114
-rw-r--r--tests/utils/utils_test.ok29
4 files changed, 186 insertions, 0 deletions
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index 0b54c880..04f2fb4b 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -49,6 +49,8 @@ char osmo_bcd2char(uint8_t bcd);
/* only works for numbers in ascci */
uint8_t osmo_char2bcd(char c);
+int osmo_bcd2str(char *dst, size_t dst_size, const uint8_t *bcd, int start_nibble, int end_nibble, bool allow_hex);
+
int osmo_hexparse(const char *str, uint8_t *b, int max_len);
char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
diff --git a/src/utils.c b/src/utils.c
index e6adcf86..4b4e6d25 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -129,6 +129,47 @@ uint8_t osmo_char2bcd(char c)
return 0;
}
+/*! Convert BCD to string.
+ * The given nibble offsets are interpreted in BCD order, i.e. nibble 0 is bcd[0] & 0xf, nibble 1 is bcd[0] >> 4, nibble
+ * 3 is bcd[1] & 0xf, etc..
+ * \param[out] dst Output string buffer, is always nul terminated when dst_size > 0.
+ * \param[in] dst_size sizeof() the output string buffer.
+ * \param[in] bcd Binary coded data buffer.
+ * \param[in] start_nibble Offset to start from, in nibbles, typically 1 to skip the first nibble.
+ * \param[in] end_nibble Offset to stop before, in nibbles, e.g. sizeof(bcd) - (bcd[0] & GSM_MI_ODD? 0:1).
+ * \param[in] allow_hex If false, return error if there are digits other than 0-9. If true, return those as [A-F].
+ * \returns The strlen that would be written if the output buffer is large enough, excluding nul byte (like
+ * snprintf()), or -EINVAL if allow_hex is false and a digit > 9 is encountered. On -EINVAL, the conversion is
+ * still completed as if allow_hex were passed as true. Return -ENOMEM if dst is NULL or dst_size is zero.
+ * If end_nibble <= start_nibble, write an empty string to dst and return 0.
+ */
+int osmo_bcd2str(char *dst, size_t dst_size, const uint8_t *bcd, int start_nibble, int end_nibble, bool allow_hex)
+{
+ char *dst_end = dst + dst_size - 1;
+ int nibble_i;
+ int rc = 0;
+
+ if (!dst || dst_size < 1)
+ return -ENOMEM;
+
+ for (nibble_i = start_nibble; nibble_i < end_nibble && dst < dst_end; nibble_i++, dst++) {
+ uint8_t nibble = bcd[nibble_i >> 1];
+ if ((nibble_i & 1))
+ nibble >>= 4;
+ nibble &= 0xf;
+
+ if (!allow_hex && nibble > 9)
+ rc = -EINVAL;
+
+ *dst = osmo_bcd2char(nibble);
+ }
+ *dst = '\0';
+
+ if (rc < 0)
+ return rc;
+ return OSMO_MAX(0, end_nibble - start_nibble);
+}
+
/*! Parse a string containing hexadecimal digits
* \param[in] str string containing ASCII encoded hexadecimal digits
* \param[out] b output buffer
diff --git a/tests/utils/utils_test.c b/tests/utils/utils_test.c
index 2bb1f9ca..a773b3f5 100644
--- a/tests/utils/utils_test.c
+++ b/tests/utils/utils_test.c
@@ -32,6 +32,7 @@
#include <time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
+#include <errno.h>
static void hexdump_test(void)
{
@@ -383,6 +384,118 @@ static void bcd_test(void)
}
}
+struct bcd2str_test {
+ const char *bcd_hex;
+ int start_nibble;
+ int end_nibble;
+ bool allow_hex;
+ size_t str_size;
+ const char *expect_str;
+ int expect_rc;
+};
+
+static const struct bcd2str_test bcd2str_tests[] = {
+ {
+ .bcd_hex = "1a 32 54 76 98 f0",
+ .start_nibble = 1,
+ .end_nibble = 11,
+ .expect_str = "1234567890",
+ .expect_rc = 10,
+ },
+ {
+ .bcd_hex = "1a 32 a4 cb 9d f0",
+ .start_nibble = 1,
+ .end_nibble = 11,
+ .expect_str = "1234ABCD90",
+ .expect_rc = -EINVAL,
+ },
+ {
+ .bcd_hex = "1a 32 a4 cb 9d f0",
+ .start_nibble = 1,
+ .end_nibble = 11,
+ .allow_hex = true,
+ .expect_str = "1234ABCD90",
+ .expect_rc = 10,
+ },
+ {
+ .bcd_hex = "1a 32 54 76 98 f0",
+ .start_nibble = 1,
+ .end_nibble = 12,
+ .expect_str = "1234567890F",
+ .expect_rc = -EINVAL,
+ },
+ {
+ .bcd_hex = "1a 32 54 76 98 f0",
+ .start_nibble = 1,
+ .end_nibble = 12,
+ .allow_hex = true,
+ .expect_str = "1234567890F",
+ .expect_rc = 11,
+ },
+ {
+ .bcd_hex = "1a 32 54 76 98 f0",
+ .start_nibble = 0,
+ .end_nibble = 12,
+ .allow_hex = true,
+ .expect_str = "A1234567890F",
+ .expect_rc = 12,
+ },
+ {
+ .bcd_hex = "1a 32 54 76 98 f0",
+ .start_nibble = 1,
+ .end_nibble = 12,
+ .str_size = 5,
+ .expect_str = "1234",
+ .expect_rc = 11,
+ },
+ {
+ .bcd_hex = "",
+ .start_nibble = 1,
+ .end_nibble = 1,
+ .expect_str = "",
+ .expect_rc = 0,
+ },
+};
+
+static void bcd2str_test(void)
+{
+ int i;
+ uint8_t bcd[64];
+ int rc;
+
+ printf("\nTesting bcd to string conversion\n");
+
+ for (i = 0; i < ARRAY_SIZE(bcd2str_tests); i++) {
+ const struct bcd2str_test *t = &bcd2str_tests[i];
+ char str[64] = {};
+ size_t str_size = t->str_size ? : sizeof(str);
+
+ osmo_hexparse(t->bcd_hex, bcd, sizeof(bcd));
+
+ printf("- BCD-input='%s' nibbles=[%d..%d[ str_size=%zu\n", t->bcd_hex,
+ t->start_nibble, t->end_nibble, str_size);
+ rc = osmo_bcd2str(str, str_size, bcd, t->start_nibble, t->end_nibble, t->allow_hex);
+
+ printf(" rc=%d\n", rc);
+
+ OSMO_ASSERT(str[str_size-1] == '\0');
+ printf(" -> %s\n", osmo_quote_str(str, -1));
+
+ if (rc != t->expect_rc)
+ printf(" ERROR: expected rc=%d\n", t->expect_rc);
+ if (strcmp(str, t->expect_str))
+ printf(" ERROR: expected result %s\n", osmo_quote_str(t->expect_str, -1));
+ }
+
+ printf("- zero output buffer\n");
+ rc = osmo_bcd2str(NULL, 100, bcd, 1, 2, false);
+ printf(" bcd2str(NULL, ...) -> %d\n", rc);
+ OSMO_ASSERT(rc < 0);
+ rc = osmo_bcd2str((char*)23, 0, bcd, 1, 2, false);
+ printf(" bcd2str(dst, 0, ...) -> %d\n", rc);
+ OSMO_ASSERT(rc < 0);
+}
+
static void str_escape_test(void)
{
int i;
@@ -810,6 +923,7 @@ int main(int argc, char **argv)
test_ipa_ccm_id_resp_parsing();
test_is_hexstr();
bcd_test();
+ bcd2str_test();
str_escape_test();
str_quote_test();
isqrt_test();
diff --git a/tests/utils/utils_test.ok b/tests/utils/utils_test.ok
index 3ea8ec6a..65e32ed2 100644
--- a/tests/utils/utils_test.ok
+++ b/tests/utils/utils_test.ok
@@ -80,6 +80,35 @@ Testing BCD conversion
val=0xe, expected=E, found=E
val=0xf, expected=F, found=F
+Testing bcd to string conversion
+- BCD-input='1a 32 54 76 98 f0' nibbles=[1..11[ str_size=64
+ rc=10
+ -> "1234567890"
+- BCD-input='1a 32 a4 cb 9d f0' nibbles=[1..11[ str_size=64
+ rc=-22
+ -> "1234ABCD90"
+- BCD-input='1a 32 a4 cb 9d f0' nibbles=[1..11[ str_size=64
+ rc=10
+ -> "1234ABCD90"
+- BCD-input='1a 32 54 76 98 f0' nibbles=[1..12[ str_size=64
+ rc=-22
+ -> "1234567890F"
+- BCD-input='1a 32 54 76 98 f0' nibbles=[1..12[ str_size=64
+ rc=11
+ -> "1234567890F"
+- BCD-input='1a 32 54 76 98 f0' nibbles=[0..12[ str_size=64
+ rc=12
+ -> "A1234567890F"
+- BCD-input='1a 32 54 76 98 f0' nibbles=[1..12[ str_size=5
+ rc=11
+ -> "1234"
+- BCD-input='' nibbles=[1..1[ str_size=64
+ rc=0
+ -> ""
+- zero output buffer
+ bcd2str(NULL, ...) -> -12
+ bcd2str(dst, 0, ...) -> -12
+
Testing string escaping
- all chars from 0 to 255 in batches of 16:
"\0\1\2\3\4\5\6\a\b\t\n\v\f\r\14\15"