Add _buf() functions to bypass static string buffers
We have a number of static buffers in use in libosmo*. This means
the related functions are not usable in a thread-safe way. While
we so far don't have many multi-threaded programs in the osmocom
universe, the static buffers also prevent us from calling the same
e.g. string-ify function twice within a single printf() call.
Let's make sure there's an alternative function in all those cases,
where the user can pass in a caller-allocated buffer + size, and make
the 'classic' function with the static buffer a wrapper around that
_buf() variant.
Change-Id: Ibf85f79e93244f53b2684ff6f1095c5b41203e05
diff --git a/src/gsm/rsl.c b/src/gsm/rsl.c
index e610ebf..7bc6002 100644
--- a/src/gsm/rsl.c
+++ b/src/gsm/rsl.c
@@ -215,33 +215,47 @@
return 0;
}
-/*! Get human-readable string for RSL channel number */
-const char *rsl_chan_nr_str(uint8_t chan_nr)
+/*! Get human-readable string for RSL channel number, in caller-provided buffer.
+ * \param[out] buf caller-provided output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] chan_nr channel number to be stringified
+ * \returns buf with string
+ */
+char *rsl_chan_nr_str_buf(char *buf, size_t buf_len, uint8_t chan_nr)
{
- static char str[20];
int ts = chan_nr & 7;
uint8_t cbits = chan_nr >> 3;
if (cbits == 0x01)
- sprintf(str, "TCH/F on TS%d", ts);
+ snprintf(buf, buf_len, "TCH/F on TS%d", ts);
else if ((cbits & 0x1e) == 0x02)
- sprintf(str, "TCH/H(%u) on TS%d", cbits & 0x01, ts);
+ snprintf(buf, buf_len, "TCH/H(%u) on TS%d", cbits & 0x01, ts);
else if ((cbits & 0x1c) == 0x04)
- sprintf(str, "SDCCH/4(%u) on TS%d", cbits & 0x03, ts);
+ snprintf(buf, buf_len, "SDCCH/4(%u) on TS%d", cbits & 0x03, ts);
else if ((cbits & 0x18) == 0x08)
- sprintf(str, "SDCCH/8(%u) on TS%d", cbits & 0x07, ts);
+ snprintf(buf, buf_len, "SDCCH/8(%u) on TS%d", cbits & 0x07, ts);
else if (cbits == 0x10)
- sprintf(str, "BCCH on TS%d", ts);
+ snprintf(buf, buf_len, "BCCH on TS%d", ts);
else if (cbits == 0x11)
- sprintf(str, "RACH on TS%d", ts);
+ snprintf(buf, buf_len, "RACH on TS%d", ts);
else if (cbits == 0x12)
- sprintf(str, "PCH/AGCH on TS%d", ts);
+ snprintf(buf, buf_len, "PCH/AGCH on TS%d", ts);
else if (cbits == 0x18)
- sprintf(str, "PDCH on TS%d", ts);
+ snprintf(buf, buf_len, "PDCH on TS%d", ts);
else
- sprintf(str, "UNKNOWN on TS%d", ts);
+ snprintf(buf, buf_len, "UNKNOWN on TS%d", ts);
- return str;
+ return buf;
+}
+
+/*! Get human-readable string for RSL channel number, in static buffer.
+ * \param[in] chan_nr channel number to be stringified
+ * \returns buf with string
+ */
+const char *rsl_chan_nr_str(uint8_t chan_nr)
+{
+ static char str[20];
+ return rsl_chan_nr_str_buf(str, sizeof(str), chan_nr);
}
static const struct value_string rsl_err_vals[] = {