/* This function converts the characters in the "in" xbuf into characters
* in the "out" xbuf. The "len" of the "in" xbuf is used starting from its
* "pos". The "size" of the "out" xbuf restricts how many characters can be
* stored, starting at its "pos+len" position. Note that the last byte of
* the buffer is never used, which reserves space for a terminating '\0'.
* We return a 0 on success or a -1 on error. An error also sets errno to
* E2BIG, EILSEQ, or EINVAL (see below); otherwise errno will be set to 0.
* The "in" xbuf is altered to update "pos" and "len". The "out" xbuf has
* data appended, and its "len" incremented. If ICB_EXPAND_OUT is set in
* "flags", the "out" xbuf will also be allocated if empty, and expanded if
* too small (so E2BIG will not be returned). If ICB_INCLUDE_BAD is set in
* "flags", any badly-encoded chars are included verbatim in the "out" xbuf,
* so EILSEQ will not be returned. Likewise for ICB_INCLUDE_INCOMPLETE with
* respect to an incomplete multi-byte char at the end, which ensures that
* EINVAL is not returned. Anytime "in.pos" is 0 we will reset the iconv()
* state prior to processing the characters. */
int iconvbufs(iconv_t ic, xbuf *in, xbuf *out, int flags)
{
ICONV_CONST char *ibuf;
size_t icnt, ocnt;
char *obuf;
if (!out->size && flags & ICB_EXPAND_OUT)
alloc_xbuf(out, 1024);
if (!in->pos)
iconv(ic, NULL, 0, NULL, 0);
ibuf = in->buf + in->pos;
icnt = in->len;
obuf = out->buf + (out->pos + out->len);
ocnt = out->size - (out->pos + out->len) - 1;
while (icnt) {
while (iconv(ic, &ibuf, &icnt, &obuf, &ocnt) == (size_t)-1) {
if (errno == EINTR)
continue;
if (errno == EINVAL) {
if (!(flags & ICB_INCLUDE_INCOMPLETE))
goto finish;
} else if (errno == EILSEQ) {
if (!(flags & ICB_INCLUDE_BAD))
goto finish;
} else {
size_t opos = obuf - out->buf;
if (!(flags & ICB_EXPAND_OUT)) {
errno = E2BIG;
goto finish;
}
realloc_xbuf(out, out->size + 1024);
obuf = out->buf + opos;
ocnt += 1024;
continue;
}
*obuf++ = *ibuf++;
ocnt--, icnt--;
}
}
errno = 0;
finish:
in->len = icnt;
in->pos = ibuf - in->buf;
out->len = obuf - out->buf - out->pos;
return errno ? -1 : 0;
}
/* This function converts the chars in the "in" xbuf into characters in the
* "out" xbuf. The ".len" chars of the "in" xbuf is used starting from its
* ".pos". The ".size" of the "out" xbuf restricts how many characters can
* be stored, starting at its ".pos+.len" position. Note that the last byte
* of the "out" xbuf is not used, which reserves space for a trailing '\0'
* (though it is up to the caller to store a trailing '\0', as needed).
*
* We return a 0 on success or a -1 on error. An error also sets errno to
* E2BIG, EILSEQ, or EINVAL (see below); otherwise errno will be set to 0.
* The "in" xbuf is altered to update ".pos" and ".len". The "out" xbuf has
* data appended, and its ".len" incremented (see below for a ".size" note).
*
* If ICB_CIRCULAR_OUT is set in "flags", the chars going into the "out" xbuf
* can wrap around to the start, and the xbuf may have its ".size" reduced
* (presumably by 1 byte) if the iconv code doesn't have space to store a
* multi-byte character at the physical end of the ".buf" (though no reducing
* happens if ".pos" is <= 1, since there is no room to wrap around).
*
* If ICB_EXPAND_OUT is set in "flags", the "out" xbuf will be allocated if
* empty, and (as long as ICB_CIRCULAR_OUT is not set) expanded if too small.
* This prevents the return of E2BIG (except for a circular xbuf).
*
* If ICB_INCLUDE_BAD is set in "flags", any badly-encoded chars are included
* verbatim in the "out" xbuf, so EILSEQ will not be returned.
*
* If ICB_INCLUDE_INCOMPLETE is set in "flags", any incomplete multi-byte
* chars are included, which ensures that EINVAL is not returned.
*
* If ICB_INIT is set, the iconv() conversion state is initialized prior to
* processing the characters. */
int iconvbufs(iconv_t ic, xbuf *in, xbuf *out, int flags)
{
ICONV_CONST char *ibuf;
size_t icnt, ocnt, opos;
char *obuf;
if (!out->size && flags & ICB_EXPAND_OUT) {
size_t siz = ROUND_UP_1024(in->len * 2);
alloc_xbuf(out, siz);
} else if (out->len+1 >= out->size) {
/* There is no room to even start storing data. */
if (!(flags & ICB_EXPAND_OUT) || flags & ICB_CIRCULAR_OUT) {
errno = E2BIG;
return -1;
}
realloc_xbuf(out, out->size + ROUND_UP_1024(in->len * 2));
}
if (flags & ICB_INIT)
iconv(ic, NULL, 0, NULL, 0);
ibuf = in->buf + in->pos;
icnt = in->len;
opos = out->pos + out->len;
if (flags & ICB_CIRCULAR_OUT) {
if (opos >= out->size) {
opos -= out->size;
/* We know that out->pos is not 0 due to the "no room" check
* above, so this can't go "negative". */
ocnt = out->pos - opos - 1;
} else {
/* Allow the use of all bytes to the physical end of the buffer
* unless pos is 0, in which case we reserve our trailing '\0'. */
ocnt = out->size - opos - (out->pos ? 0 : 1);
}
} else
ocnt = out->size - opos - 1;
obuf = out->buf + opos;
while (icnt) {
while (iconv(ic, &ibuf, &icnt, &obuf, &ocnt) == (size_t)-1) {
if (errno == EINTR)
continue;
if (errno == EINVAL) {
if (!(flags & ICB_INCLUDE_INCOMPLETE))
goto finish;
} else if (errno == EILSEQ) {
if (!(flags & ICB_INCLUDE_BAD))
goto finish;
} else if (errno == E2BIG) {
size_t siz;
opos = obuf - out->buf;
if (flags & ICB_CIRCULAR_OUT && out->pos > 1 && opos > out->pos) {
/* We are in a divided circular buffer at the physical
* end with room to wrap to the start. If iconv() refused
* to use one or more trailing bytes in the buffer, we
* set the size to ignore the unused bytes. */
if (opos < out->size)
reduce_iobuf_size(out, opos);
obuf = out->buf;
ocnt = out->pos - 1;
continue;
}
if (!(flags & ICB_EXPAND_OUT) || flags & ICB_CIRCULAR_OUT) {
errno = E2BIG;
goto finish;
}
siz = ROUND_UP_1024(in->len * 2);
realloc_xbuf(out, out->size + siz);
obuf = out->buf + opos;
ocnt += siz;
continue;
} else {
rsyserr(FERROR, errno, "unexpected error from iconv()");
exit_cleanup(RERR_UNSUPPORTED);
}
*obuf++ = *ibuf++;
ocnt--, icnt--;
}
}
errno = 0;
finish:
opos = obuf - out->buf;
if (flags & ICB_CIRCULAR_OUT && opos < out->pos)
opos += out->size;
out->len = opos - out->pos;
in->len = icnt;
in->pos = ibuf - in->buf;
return errno ? -1 : 0;
}
