On 7/31/2024 11:21 AM, Takashi Iwai wrote:
On Wed, 31 Jul 2024 10:46:08 +0200,
Amadeusz Sławiński wrote:
On 6/19/2024 5:28 PM, Takashi Iwai wrote:
For making it easer for applications to create a virtual UMP Endpoint
and UMP blocks, add two API helper functions.
snd_seq_create_ump_endpoint() creates (unsurprisingly) a UMP Endpoint,
based on the given snd_ump_endpoint_info_t information. The number of
(max) UMP groups belonging to this Endpoint has to be specified.
This function sets up the Endpoint info on the sequencer client, and
creates a MIDI 2.0 UMP port as well as UMP Group ports automatically.
The name of the sequencer client is updated from the Endpoint name,
too.
After creating a UMP Endpoint, create each UMP Block via
snd_seq_create_ump_block() function with a snd_ump_block_info_t info.
The associated groups for each block have to be specified there.
The port names and capability bits are updated accordingly after
setting each block information.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
...
+ if (*blknames) {
+ strlcat(blknames, ", ", sizeof(blknames));
+ strlcat(blknames, (const char *)bp->name,
+ sizeof(blknames));
FYI, this seems to introduce build problems on systems that do not
have strlcpy:
During build:
seqmid.c: In function ‘update_group_ports’:
seqmid.c:672:33: warning: implicit declaration of function
‘strlcat’; did you mean ‘strncat’?
[-Wimplicit-function-declaration]
672 | strlcat(blknames, ", ",
sizeof(blknames));
| ^~~~~~~
| strncat
And then during linking:
/usr/bin/ld: seq/.libs/libseq.a(seqmid.o): in function `update_group_ports':
/home/amade/workdir/avs/alsa-lib/src/seq/seqmid.c:672: undefined
reference to `strlcat'
/usr/bin/ld: /home/amade/workdir/avs/alsa-lib/src/seq/seqmid.c:673:
undefined reference to `strlcat'
collect2: error: ld returned 1 exit status
Thanks, I'll modify it to avoid strlcat() like below.
Takashi
-- 8< --
Subject: [PATCH] seq: Avoid strlcat()
strlcat() isn't available in every system, so better to avoid it.
Rewrite the code without strlcat().
Fixes: 6167b8ce3e80 ("seq: Add API helper functions for creating UMP Endpoint and Blocks")
Link: https://lore.kernel.org/0796c157-1ac3-47a3-9d54-ba86f59d64d5@xxxxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
src/seq/seqmid.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/seq/seqmid.c b/src/seq/seqmid.c
index 08c62d5c24b8..b30db4075254 100644
--- a/src/seq/seqmid.c
+++ b/src/seq/seqmid.c
@@ -635,6 +635,7 @@ static void update_group_ports(snd_seq_t *seq, snd_ump_endpoint_info_t *ep)
char blknames[64];
char name[64];
unsigned int caps = 0;
+ int len;
blknames[0] = 0;
for (b = 0; b < ep->num_blocks; b++) {
@@ -668,14 +669,13 @@ static void update_group_ports(snd_seq_t *seq, snd_ump_endpoint_info_t *ep)
if (!*bp->name)
continue;
- if (*blknames) {
- strlcat(blknames, ", ", sizeof(blknames));
- strlcat(blknames, (const char *)bp->name,
- sizeof(blknames));
- } else {
+ len = strlen(blknames);
+ if (len)
+ snprintf(blknames + len, sizeof(blknames) - len,
+ ", %s", bp->name);
+ else
snd_strlcpy(blknames, (const char *)bp->name,
sizeof(blknames));
- }
}
if (!*blknames)
Builds now, but still gives warning:
seqmid.c: In function ‘update_group_ports’:
seqmid.c:675:45: warning: ‘%s’ directive output may be truncated writing
up to 127 bytes into a region of size 61 [-Wformat-truncation=]
675 | ", %s", bp->name);
| ^~
In file included from /usr/include/stdio.h:894,
from ../../include/local.h:28,
from seq_local.h:26,
from seqmid.c:23:
In function ‘snprintf’,
inlined from ‘update_group_ports’ at seqmid.c:674:5:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:71:10: note:
‘__builtin___snprintf_chk’ output between 3 and 130 bytes into a
destination of size 63
71 | return __builtin___snprintf_chk (__s, __n,
__USE_FORTIFY_LEVEL - 1,
|
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
72 | __glibc_objsize (__s), __fmt,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
73 | __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~
