From: Martin Wilck <mwilck@xxxxxxxx>
By using the strbuf API, the code gets more readable, as we need
less output size checks.
While at it, avoid a possible crash by passing a NULL pointer
to memchr().
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/discovery.c | 113 +++++++++++++++++----------------------
1 file changed, 49 insertions(+), 64 deletions(-)
diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index 5ce9031..16b6fae 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -1120,6 +1120,7 @@ parse_vpd_pg83(const unsigned char *in, size_t in_len,
size_t len, vpd_len, i;
int vpd_type, prio = -1;
int err = -ENODATA;
+ STRBUF_ON_STACK(buf);
/* Need space at least for one digit */
if (out_len <= 1)
@@ -1237,92 +1238,76 @@ parse_vpd_pg83(const unsigned char *in, size_t in_len,
if (vpd_type == 0x2 || vpd_type == 0x3) {
size_t i;
- len = sprintf(out, "%d", vpd_type);
- if (2 * vpd_len >= out_len - len) {
- condlog(1, "%s: WWID overflow, type %d, %zu/%zu bytes required",
- __func__, vpd_type,
- 2 * vpd_len + len + 1, out_len);
- vpd_len = (out_len - len - 1) / 2;
- }
+ if ((err = print_strbuf(&buf, "%d", vpd_type)) < 0)
+ return err;
for (i = 0; i < vpd_len; i++)
- len += sprintf(out + len,
- "%02x", vpd[i]);
+ if ((err = print_strbuf(&buf, "%02x", vpd[i])) < 0)
+ return err;
} else if (vpd_type == 0x8) {
- if (!memcmp("eui.", vpd, 4))
- out[0] = '2';
+ char type;
+
+ if (!memcmp("eui.", vpd, 4))
+ type = '2';
else if (!memcmp("naa.", vpd, 4))
- out[0] = '3';
+ type = '3';
else
- out[0] = '8';
+ type = '8';
+ if ((err = fill_strbuf(&buf, type, 1)) < 0)
+ return err;
vpd += 4;
len = vpd_len - 4;
- while (len > 2 && vpd[len - 2] == '\0')
- --len;
- if (len > out_len - 1) {
- condlog(1, "%s: WWID overflow, type 8/%c, %zu/%zu bytes required",
- __func__, out[0], len + 1, out_len);
- len = out_len - 1;
+ if ((err = __append_strbuf_str(&buf, (const char *)vpd, len)) < 0)
+ return err;
+
+ /* The input is 0-padded, make sure the length is correct */
+ truncate_strbuf(&buf, strlen(get_strbuf_str(&buf)));
+ len = get_strbuf_len(&buf);
+ if (type != '8') {
+ char *buffer = __get_strbuf_buf(&buf);
+
+ for (i = 0; i < len; ++i)
+ buffer[i] = tolower(buffer[i]);
}
- if (out[0] == '8')
- for (i = 0; i < len; ++i)
- out[1 + i] = vpd[i];
- else
- for (i = 0; i < len; ++i)
- out[1 + i] = tolower(vpd[i]);
-
- /* designator should be 0-terminated, but let's make sure */
- out[len] = '\0';
-
} else if (vpd_type == 0x1) {
const unsigned char *p;
size_t p_len;
- out[0] = '1';
- len = 1;
- while ((p = memchr(vpd, ' ', vpd_len))) {
+ if ((err = fill_strbuf(&buf, '1', 1)) < 0)
+ return err;
+ while (vpd && (p = memchr(vpd, ' ', vpd_len))) {
p_len = p - vpd;
- if (len + p_len > out_len - 1) {
- condlog(1, "%s: WWID overflow, type 1, %zu/%zu bytes required",
- __func__, len + p_len, out_len);
- p_len = out_len - len - 1;
- }
- memcpy(out + len, vpd, p_len);
- len += p_len;
- if (len >= out_len - 1) {
- out[len] = '\0';
- break;
- }
- out[len] = '_';
- len ++;
- if (len >= out_len - 1) {
- out[len] = '\0';
- break;
- }
+ if ((err = __append_strbuf_str(&buf, (const char *)vpd,
+ p_len)) < 0)
+ return err;
vpd = p;
vpd_len -= p_len;
- while (vpd && *vpd == ' ') {
+ while (vpd && vpd_len > 0 && *vpd == ' ') {
vpd++;
vpd_len --;
}
+ if (vpd_len > 0 && (err = fill_strbuf(&buf, '_', 1)) < 0)
+ return err;
}
- p_len = vpd_len;
- if (p_len > 0 && len < out_len - 1) {
- if (len + p_len > out_len - 1) {
- condlog(1, "%s: WWID overflow, type 1, %zu/%zu bytes required",
- __func__, len + p_len + 1, out_len);
- p_len = out_len - len - 1;
- }
- memcpy(out + len, vpd, p_len);
- len += p_len;
- out[len] = '\0';
- }
- if (len > 1 && out[len - 1] == '_') {
- out[len - 1] = '\0';
- len--;
+ if (vpd_len > 0) {
+ if ((err = __append_strbuf_str(&buf, (const char *)vpd,
+ vpd_len)) < 0)
+ return err;
}
}
+
+ len = get_strbuf_len(&buf);
+ if (len >= out_len) {
+ condlog(1, "%s: WWID overflow, type %d, %zu/%zu bytes required",
+ __func__, vpd_type, len, out_len);
+ if (vpd_type == 2 || vpd_type == 3)
+ /* designator must have an even number of characters */
+ len = 2 * (out_len / 2) - 1;
+ else
+ len = out_len - 1;
+ }
+ strlcpy(out, get_strbuf_str(&buf), len + 1);
return len;
}
--
2.33.1
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