Hi Heinrich, On Mon, 18 Apr 2022 at 16:47, Masahisa Kojima <masahisa.koj...@linaro.org> wrote: > > On Sat, 16 Apr 2022 at 16:32, Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > > > On 3/24/22 14:54, Masahisa Kojima wrote: > > > Provide u16 string version of strlcat(). > > > > > > Signed-off-by: Masahisa Kojima <masahisa.koj...@linaro.org> > > > Reviewed-by: Simon Glass <s...@chromium.org> > > > --- > > > Changes in v4: > > > - add blank line above the return statement > > > > > > Changes in v2: > > > - implement u16_strlcat(with the destination buffer size in argument) > > > instead of u16_strcat > > > > > > include/charset.h | 15 +++++++++++++++ > > > lib/charset.c | 21 +++++++++++++++++++++ > > > 2 files changed, 36 insertions(+) > > > > > > diff --git a/include/charset.h b/include/charset.h > > > index b93d023092..dc5fc275ec 100644 > > > --- a/include/charset.h > > > +++ b/include/charset.h > > > @@ -259,6 +259,21 @@ u16 *u16_strcpy(u16 *dest, const u16 *src); > > > */ > > > u16 *u16_strdup(const void *src); > > > > > > +/** > > > + * u16_strlcat() - Append a length-limited, %NUL-terminated string to > > > another > > > + * > > > + * Append the src string to the dest string, overwriting the terminating > > > + * null word at the end of dest, and then adds a terminating null word. > > > + * It will append at most size - u16_strlen(dst) - 1 bytes, > > > NUL-terminating the result. > > > > Why "- 1"? > > It is my mistake, it should be 2. > > > > > If size is even, we append up to size - u16_strlen(dst) - 2 bytes. The > > two extra bytes used for 0x0000. > > If size is odd, we append up to size - u16_strlen(dst) - 3 bytes leaving > > one byte of the buffer unused.
To make behavior simple, I update the meaning of the 3rd parameter from buffer size to u16 string count. It is the same behavior as other u16_strxxx functions in U-boot. Thanks, Masahisa Kojima > > Thanks, It clearly explains the behavior. > > > > > > + * > > > + * @dest: destination buffer (null terminated) > > > + * @src: source buffer (null terminated) > > > + * @size: destination buffer size in bytes > > > > s/$/ including the trailing 0x0000/ > > OK, I will update "(null terminated)" to the suggested one. > > > > > > + * Return: total size of the created string in bytes. > > > + * If return value >= size, truncation occurred. > > > + */ > > > +size_t u16_strlcat(u16 *dest, const u16 *src, size_t size); > > > + > > > /** > > > * utf16_to_utf8() - Convert an utf16 string to utf8 > > > * > > > diff --git a/lib/charset.c b/lib/charset.c > > > index f44c58d9d8..47997eca7d 100644 > > > --- a/lib/charset.c > > > +++ b/lib/charset.c > > > @@ -428,6 +428,27 @@ u16 *u16_strdup(const void *src) > > > return new; > > > } > > > > > > +size_t u16_strlcat(u16 *dest, const u16 *src, size_t size) > > > +{ > > > > If you start the function with > > > > size >>= 1; > > > > or > > > > size /= sizeof(u16); > > > > this might simplify the code. > > In u16_strlcat(), there are two size definitions, u16 string size and > buffer size. > I will rename some of the variables to clearly identify the meaning. > > > > > > + size_t dstrlen = u16_strnlen(dest, size >> 1); > > > + size_t dlen = dstrlen * sizeof(u16); > > > + size_t len = u16_strlen(src) * sizeof(u16); > > > + size_t ret = dlen + len; > > > > This misses the trailing 0x0000. > > Strlcat() is not the C standard function, but the linux implementation > of strlcat() does not include trailing 0x00[1], > also the same for openbsd. > [1] https://github.com/torvalds/linux/blob/master/lib/string.c#L319. > > The current U-Boot strlcat() contains trailing 0x00, I think it needs > to be updated. > > Thanks, > Masahisa Kojima > > > > > Best regards > > > > Heinrich > > > > > + > > > + if (dlen >= size) > > > + return ret; > > > + > > > + dest += dstrlen; > > > + size -= dlen; > > > + if (len >= size) > > > + len = size - sizeof(u16); > > > + > > > + memcpy(dest, src, len); > > > + dest[len >> 1] = u'\0'; > > > + > > > + return ret; > > > +} > > > + > > > /* Convert UTF-16 to UTF-8. */ > > > uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size) > > > { > >