diff options
| -rw-r--r-- | include/osmocom/core/msgb.h | 1 | ||||
| -rw-r--r-- | src/msgb.c | 48 | ||||
| -rw-r--r-- | tests/msgb/msgb_test.c | 105 | ||||
| -rw-r--r-- | tests/msgb/msgb_test.ok | 8 |
4 files changed, 162 insertions, 0 deletions
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h index 91b7ec7e..9c3ccf0d 100644 --- a/include/osmocom/core/msgb.h +++ b/include/osmocom/core/msgb.h @@ -498,5 +498,6 @@ uint8_t *msgb_data(const struct msgb *msg); 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, ...); /*! @} */ @@ -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 +379,49 @@ const char *msgb_hexdump(const struct msgb *msg) return buf; } + +/*! Print a string to the end of message buffer. + * \param[in] msg message buffer + * \returns 0 on success, -EINVAL on error + * + * The resulting string is printed to the msgb without a trailing nul + * character. A nul following the data tail may be written as an implementation + * detail, but a trailing nul is never part of the msgb data in terms of + * msgb_length(). + * + * Note: the tailroom must always be one byte longer than the string to be + * written. The msgb is filled only up to tailroom=1. This is an implementation + * detail that allows leaving a nul character behind the valid data. + * + * In case of error, the msgb remains unchanged, though data may have been + * written to the (unused) memory after the tail pointer. + */ +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) { + 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 ac103829..05335467 100644 --- a/tests/msgb/msgb_test.c +++ b/tests/msgb/msgb_test.c @@ -277,6 +277,110 @@ static void test_msgb_resize_area() osmo_set_panic_handler(NULL); } +static void test_msgb_printf() +{ + struct msgb *msg; + struct msgb *msg_ref; + int rc; + int total_len; + + msg = msgb_alloc(80, "data"); + + /* Add normal text: */ + printf("Add normal text:\n"); + rc = msgb_printf(msg, "|this is a test %i, %s, %16x|", 4711, "testme", + 0x4711); + total_len = msgb_length(msg); + printf("#1: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len, + msg->data); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(msgb_tailroom(msg) == 33); + + /* Add normal text: */ + rc = msgb_printf(msg, "|some more text|"); + total_len = msgb_length(msg); + printf("#2: rc=%i, total_len=%i, msg->data=%s\n", rc, total_len, + msg->data); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(msgb_tailroom(msg) == 17); + + /* Add normal text which will not fit: */ + rc = msgb_printf(msg, "|more %i %x %s|", 23, 0xfee, + "text will not fit"); + total_len = msgb_length(msg); + 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 = msgb_length(msg); + 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(msgb_length(msg) == 63); + + /* Add normal text which just fits */ + rc = msgb_printf(msg, "|more 123456 AB|"); + total_len = msgb_length(msg); + 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 Space. + * 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(msgb_length(msg) == 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 = msgb_length(msg); + 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(msgb_length(msg) == 79); + + msgb_free(msg); + + /* Test behaviour when a completely full buffer is passed to + * msgb_printf(). We should get rc == -EINVAL and the message + * buffer must not be changed at all */ + msg = msgb_alloc(15, "data"); + msg_ref = msgb_alloc(msgb_tailroom(msg), "data"); + memset(msg->data, 0x41, msgb_tailroom(msg)); + memset(msg_ref->data, 0x41, msgb_tailroom(msg_ref)); + msgb_put(msg, msgb_tailroom(msg)); + msgb_put(msg_ref, msgb_tailroom(msg_ref)); + + printf("#7: before: %s", msgb_hexdump(msg)); + rc = msgb_printf(msg, "ABCDEF"); + printf(" after: rc=%i, %s", rc, msgb_hexdump(msg)); + if (memcmp(msg->data, msg_ref->data, msgb_length(msg)) == 0) + printf(" ==> ok, no change\n"); + else + printf(" ==> error, change detected\n"); + OSMO_ASSERT(rc == -EINVAL); + OSMO_ASSERT(msgb_tailroom(msg) == 0); + OSMO_ASSERT(msgb_length(msg) == msgb_length(msg_ref)); + + msgb_free(msg); + msgb_free(msg_ref); +} + static struct log_info info = {}; int main(int argc, char **argv) @@ -287,6 +391,7 @@ int main(int argc, char **argv) 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 6603fe71..826c809c 100644 --- a/tests/msgb/msgb_test.ok +++ b/tests/msgb/msgb_test.ok @@ -32,4 +32,12 @@ Testing msgb_resize_area 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||more 23 fee tex +#4: rc=-22, total_len=63, msg->data=|this is a test 4711, testme, 4711||some more text||more 123456 ABC +#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| +#7: before: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 after: rc=-22, 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 ==> ok, no change Success. |