From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Sat, 1 Oct 2022 06:53:33 +0000 (+0900)
Subject: sd-dhcp6-client: use GREEDY_REALLOC() in dhcp6_option_append_vendor_class()
X-Git-Tag: v252-rc2~68^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cb9c303d70a30853898a2833634949ad35e9fa41;p=thirdparty%2Fsystemd.git

sd-dhcp6-client: use GREEDY_REALLOC() in dhcp6_option_append_vendor_class()
---

diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index f0a6b53a429..d258c9aafae 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -424,8 +424,7 @@ int dhcp6_option_append_user_class(uint8_t **buf, size_t *buflen, char * const *
 
 int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *buflen, char * const *vendor_class) {
         _cleanup_free_ uint8_t *p = NULL;
-        uint32_t enterprise_identifier;
-        size_t total, offset;
+        size_t n = 0;
 
         assert(buf);
         assert(*buf);
@@ -434,36 +433,28 @@ int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *buflen, char * const
         if (strv_isempty(vendor_class))
                 return 0;
 
-        enterprise_identifier = htobe32(SYSTEMD_PEN);
-
-        p = memdup(&enterprise_identifier, sizeof(enterprise_identifier));
-        if (!p)
+        if (!GREEDY_REALLOC(p, sizeof(be32_t)))
                 return -ENOMEM;
 
-        total = sizeof(enterprise_identifier);
-        offset = total;
+        /* Enterprise Identifier */
+        unaligned_write_be32(p, SYSTEMD_PEN);
+        n += sizeof(be32_t);
 
         STRV_FOREACH(s, vendor_class) {
                 size_t len = strlen(*s);
-                uint8_t *q;
 
                 if (len > UINT16_MAX || len == 0)
                         return -EINVAL;
 
-                q = realloc(p, total + len + 2);
-                if (!q)
+                if (!GREEDY_REALLOC(p, n + len + 2))
                         return -ENOMEM;
 
-                p = q;
-
-                unaligned_write_be16(&p[offset], len);
-                memcpy(&p[offset + 2], *s, len);
-
-                offset += 2 + len;
-                total += 2 + len;
+                unaligned_write_be16(p + n, len);
+                memcpy(p + n + 2, *s, len);
+                n += len + 2;
         }
 
-        return dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_VENDOR_CLASS, total, p);
+        return dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_VENDOR_CLASS, n, p);
 }
 
 int dhcp6_option_parse(