This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/gerrit-log@lists.osmocom.org/.
dexter gerrit-no-reply at lists.osmocom.orgHello Max, Jenkins Builder,
I'd like you to reexamine a change. Please visit
https://gerrit.osmocom.org/4200
to look at the new patch set (#3).
add function msgb_printf() to print formatted text into msg buf
In ASCII string based protocols it a printf() version that prints
directly to the message buffer may be useful.
Add function msgb_printf(), make sure that msg buffer bounderies
are not exceeded. If the end of the tail buffer is hit, return
with an error code.
Change-Id: I15e1af68616309555d0ed9ac5da027c9833d42e3
---
M include/osmocom/core/msgb.h
M src/msgb.c
M tests/msgb/msgb_test.c
M tests/msgb/msgb_test.ok
4 files changed, 136 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/00/4200/3
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 91b7ec7..9c3ccf0 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -498,5 +498,6 @@
void *msgb_talloc_ctx_init(void *root_ctx, unsigned int pool_size);
void msgb_set_talloc_ctx(void *ctx) OSMO_DEPRECATED("Use msgb_talloc_ctx_init() instead");
+int msgb_printf(struct msgb *msgb, const char *format, ...);
/*! @} */
diff --git a/src/msgb.c b/src/msgb.c
index 2e9f4a2..46287b5 100644
--- a/src/msgb.c
+++ b/src/msgb.c
@@ -55,6 +55,9 @@
#include <string.h>
#include <stdlib.h>
#include <inttypes.h>
+#include <stdarg.h>
+#include <errno.h>
+
#include <osmocom/core/msgb.h>
//#include <openbsc/gsm_data.h>
@@ -376,4 +379,56 @@
return buf;
}
+
+/*! Print a string to the end of message buffer
+ * \param[in] msg message buffer
+ * \returns 0 on success, -EINVAL on error
+ *
+ * If less then 1 character of tailroom is left over, the message buffer
+ * will not be changed at all.
+ *
+ * In case of error, the message buffer may be left with invalid data
+ * appended. However, if an error is detected the tail pointer will not
+ * be moved and a terminating \0 is written to the tail position, this
+ * will clamp off the truncated string. The message buffer is immediately
+ * ready for a second attempt (with less data).
+ *
+ * In case of success the resulting string is written to the memory where
+ * the tail pointer points to. The tail pointer is then moved to the end
+ * of the string so that it points exactly to the location of the string
+ * terminator.
+ *
+ * When msgb_printf() is called multiple times with different data, the
+ * result will be a single, concatenated string.
+ */
+int msgb_printf(struct msgb *msgb, const char *format, ...)
+{
+ va_list args;
+ int str_len;
+ int rc = 0;
+
+ OSMO_ASSERT(msgb);
+ OSMO_ASSERT(format);
+
+ /* Regardless of what we plan to add to the buffer, we must at least
+ * be able to store a string terminator (nullstring) */
+ if (msgb_tailroom(msgb) < 1)
+ return -EINVAL;
+
+ va_start(args, format);
+
+ str_len =
+ vsnprintf((char *)msgb->tail, msgb_tailroom(msgb), format, args);
+
+ if (str_len >= msgb_tailroom(msgb) || str_len < 0) {
+ *msgb->tail = '\0';
+ rc = -EINVAL;
+ } else
+ msgb_put(msgb, str_len);
+
+ va_end(args);
+ return rc;
+}
+
+
/*! @} */
diff --git a/tests/msgb/msgb_test.c b/tests/msgb/msgb_test.c
index ac10382..edc2412 100644
--- a/tests/msgb/msgb_test.c
+++ b/tests/msgb/msgb_test.c
@@ -276,6 +276,78 @@
osmo_set_panic_handler(NULL);
}
+static void test_msgb_printf()
+{
+ struct msgb *msg = msgb_alloc(80, "data");
+ int rc;
+ int total_len;
+
+ /* Add normal text: */
+ printf("Add normal text:\n");
+ rc = msgb_printf(msg, "|this is a test %i, %s, %16x|", 4711, "testme",
+ 0x4711);
+ total_len = strlen((char *)msg->data);
+ printf("#1: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == 0);
+
+ /* Add normal text: */
+ rc = msgb_printf(msg, "|some more text|");
+ total_len = strlen((char *)msg->data);
+ printf("#2: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == 0);
+
+ /* Add normal text which will not fit: */
+ rc = msgb_printf(msg, "|more %i %x %s|", 23, 0xfee,
+ "text will not fit");
+ total_len = strlen((char *)msg->data);
+ printf("#3: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == -EINVAL);
+
+ /* Check if we got the right amount of characters in the message buffer
+ * until here, so that we can be sure that the following cornercase
+ * tests yield plausible results */
+ OSMO_ASSERT(msgb_tailroom(msg) == 17);
+
+ /* Add normal text which just does not fit by one character, this should not
+ * alter the message buffers tail pointer */
+ rc = msgb_printf(msg, "|more 123456 ABC|");
+ total_len = strlen((char *)msg->data);
+ printf("#4: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == -EINVAL);
+
+ /* Make sure the tailroom, nor the contained string length did change */
+ OSMO_ASSERT(msgb_tailroom(msg) == 17);
+ OSMO_ASSERT(total_len == 63);
+
+ /* Add normal text which just fits */
+ rc = msgb_printf(msg, "|more 123456 AB|");
+ total_len = strlen((char *)msg->data);
+ printf("#5: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == 0);
+
+ /* Make sure that the string in the bufer takes up all available
+ * also make sure that the available tailroom has space for one byte,
+ * which actually holds the string terminator */
+ OSMO_ASSERT(msgb_tailroom(msg) == 1);
+ OSMO_ASSERT(total_len == 79);
+
+ /* Try to add a nullstring to the already full buffer, this should
+ * be ok, since we still have one byte tailroom */
+ rc = msgb_printf(msg, "");
+ total_len = strlen((char *)msg->data);
+ printf("#6: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len,
+ msg->data);
+ OSMO_ASSERT(rc == 0);
+
+ /* Make sure that we still have the same conditions as before */
+ OSMO_ASSERT(msgb_tailroom(msg) == 1);
+ OSMO_ASSERT(total_len == 79);
+}
static struct log_info info = {};
@@ -287,6 +359,7 @@
test_msgb_api_errors();
test_msgb_copy();
test_msgb_resize_area();
+ test_msgb_printf();
printf("Success.\n");
diff --git a/tests/msgb/msgb_test.ok b/tests/msgb/msgb_test.ok
index 6603fe7..3638515 100644
--- a/tests/msgb/msgb_test.ok
+++ b/tests/msgb/msgb_test.ok
@@ -32,4 +32,11 @@
Original: [L1]> 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 [L2]> 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 [L3]> 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 38 39 3a 3b [L4]> 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
Extended: [L1]> 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 [L2]> 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [L3]> 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 38 39 3a 3b [L4]> 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
Shrinked: [L1]> 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 [L2]> 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [L3]> 28 29 2a 2b 2c 2d 2e 2f 30 31 [L4]> 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
+Add normal text:
+#1: rc=0, total_len=47, msg->data=|this is a test 4711, testme, 4711|
+#2: rc=0, total_len=63, msg->data=|this is a test 4711, testme, 4711||some more text|
+#3: rc=-22, total_len=63, msg->data=|this is a test 4711, testme, 4711||some more text|
+#4: rc=-22, total_len=63, msg->data=|this is a test 4711, testme, 4711||some more text|
+#5: rc=0, total_len=79, msg->data=|this is a test 4711, testme, 4711||some more text||more 123456 AB|
+#6: rc=0, total_len=79, msg->data=|this is a test 4711, testme, 4711||some more text||more 123456 AB|
Success.
--
To view, visit https://gerrit.osmocom.org/4200
To unsubscribe, visit https://gerrit.osmocom.org/settings
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I15e1af68616309555d0ed9ac5da027c9833d42e3
Gerrit-PatchSet: 3
Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Owner: dexter <pmaier at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Max <msuraev at sysmocom.de>