Max has uploaded this change for review. ( https://gerrit.osmocom.org/12573
Change subject: Add function to combine nibbles into byte
......................................................................
Add function to combine nibbles into byte
It's a very common patter throughout GSM 04.08 and other protocols where
single byte store 2 different values occupying 1 nibble each.
Change-Id: I380687c31a787c0a109819f7c3b2946eae52675e
---
M include/osmocom/core/bits.h
M include/osmocom/gsm/gsm0808_utils.h
M include/osmocom/gsm/gsm48.h
M include/osmocom/gsm/protocol/gsm_03_41.h
M src/gsm/gsm0808.c
M src/gsm/gsm23003.c
M src/gsm/gsm48.c
M tests/utils/utils_test.c
8 files changed, 21 insertions(+), 9 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/73/12573/1
diff --git a/include/osmocom/core/bits.h b/include/osmocom/core/bits.h
index b1b8040..8027bdd 100644
--- a/include/osmocom/core/bits.h
+++ b/include/osmocom/core/bits.h
@@ -47,6 +47,16 @@
int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
+/*! Nibble combination.
+ * \param[in] lo Value to be placed in LSB nibble
+ * \param[in] hi Value to be placed in LSB nibble
+ * \returns combined nibble value
+ */
+static inline uint8_t osmo_nibble(uint8_t lo, uint8_t hi)
+{
+ return lo | (hi << 4);
+}
+
void osmo_nibble_shift_right(uint8_t *out, const uint8_t *in,
unsigned int num_nibbles);
void osmo_nibble_shift_left_unal(uint8_t *out, const uint8_t *in,
diff --git a/include/osmocom/gsm/gsm0808_utils.h
b/include/osmocom/gsm/gsm0808_utils.h
index 4a2233e..4cc917b 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -237,7 +237,7 @@
return 0;
}
- return channel_mode << 4 | channel;
+ return osmo_nibble(channel, channel_mode);
}
const char *gsm0808_channel_type_name(const struct gsm0808_channel_type *ct);
diff --git a/include/osmocom/gsm/gsm48.h b/include/osmocom/gsm/gsm48.h
index 0f5727a..69b2eeb 100644
--- a/include/osmocom/gsm/gsm48.h
+++ b/include/osmocom/gsm/gsm48.h
@@ -71,4 +71,4 @@
uint8_t pdisc, uint8_t msg_type);
#define gsm48_push_l3hdr_tid(msg, pdisc, tid, msg_type) \
- gsm48_push_l3hdr(msg, (pdisc & 0x0f) | (tid << 4), msg_type)
+ gsm48_push_l3hdr(msg, osmo_nibble(pdisc & 0x0f, tid), msg_type)
diff --git a/include/osmocom/gsm/protocol/gsm_03_41.h
b/include/osmocom/gsm/protocol/gsm_03_41.h
index 1b399ae..cd84fd4 100644
--- a/include/osmocom/gsm/protocol/gsm_03_41.h
+++ b/include/osmocom/gsm/protocol/gsm_03_41.h
@@ -5,6 +5,7 @@
#include <stdint.h>
+#include <osmocom/core/bits.h>
#include <osmocom/core/endian.h>
#include <osmocom/gsm/protocol/gsm_04_12.h>
@@ -73,7 +74,7 @@
uint8_t data[0];
} __attribute__((packed));
-#define GSM341_MSG_CODE(ms) ((ms)->serial.code_lo | ((ms)->serial.code_hi <<
4))
+#define GSM341_MSG_CODE(ms) osmo_nibble((ms)->serial.code_lo,
(ms)->serial.code_hi)
/* Section 9.3.2.1 - Geographical Scope */
#define GSM341_GS_CELL_WIDE_IMMED 0
diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c
index 59b1657..2254630 100644
--- a/src/gsm/gsm0808.c
+++ b/src/gsm/gsm0808.c
@@ -293,7 +293,7 @@
return NULL;
/* Set cause code class in the upper byte */
- cause = 0x80 | (class << 4);
+ cause = osmo_nibble(0x80, class);
cause = cause << 8;
/* Set cause code extension in the lower byte */
diff --git a/src/gsm/gsm23003.c b/src/gsm/gsm23003.c
index 1d9cefe..eaf0fb4 100644
--- a/src/gsm/gsm23003.c
+++ b/src/gsm/gsm23003.c
@@ -32,6 +32,7 @@
#include <osmocom/gsm/gsm23003.h>
#include <osmocom/gsm/protocol/gsm_23_003.h>
#include <osmocom/core/utils.h>
+#include <osmocom/core/bits.h>
static bool is_n_digits(const char *str, int min_digits, int max_digits)
{
@@ -218,10 +219,10 @@
to_bcd(bcd, plmn->mnc);
if (plmn->mnc > 99 || plmn->mnc_3_digits) {
bcd_dst[1] |= bcd[2] << 4;
- bcd_dst[2] = bcd[0] | (bcd[1] << 4);
+ bcd_dst[2] = osmo_nibble(bcd[0], bcd[1]);
} else {
bcd_dst[1] |= 0xf << 4;
- bcd_dst[2] = bcd[1] | (bcd[2] << 4);
+ bcd_dst[2] = osmo_nibble(bcd[1], bcd[2]);
}
}
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index 795e98b..e5d1592 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -659,7 +659,7 @@
else
upper = osmo_char2bcd(id[++off]) & 0x0f;
- buf[2 + i] = (upper << 4) | lower;
+ buf[2 + i] = osmo_nibble(lower, upper);
}
return 2 + buf[1];
diff --git a/tests/utils/utils_test.c b/tests/utils/utils_test.c
index a773b3f..b677a5f 100644
--- a/tests/utils/utils_test.c
+++ b/tests/utils/utils_test.c
@@ -510,7 +510,7 @@
in_buf[16] = '\0';
for (j = 0; j < 16; j++) {
for (i = 0; i < 16; i++)
- in_buf[i] = (j << 4) | i;
+ in_buf[i] = osmo_nibble(i, j);
printf("\"%s\"\n", osmo_escape_str((const char*)in_buf, 16));
}
@@ -558,7 +558,7 @@
in_buf[16] = '\0';
for (j = 0; j < 16; j++) {
for (i = 0; i < 16; i++)
- in_buf[i] = (j << 4) | i;
+ in_buf[i] = osmo_nibble(i, j);
printf("'%s'\n", osmo_quote_str((const char*)in_buf, 16));
}
--
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Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I380687c31a787c0a109819f7c3b2946eae52675e
Gerrit-Change-Number: 12573
Gerrit-PatchSet: 1
Gerrit-Owner: Max <msur...@sysmocom.de>
