firewall-util: use fixed size array for chain name

xt_chainlabel is defined as
```
typedef char xt_chainlabel[32];
```

diff --git a/src/shared/firewall-util.c b/src/shared/firewall-util.c
index 87bc3f7..93bdd8c 100644 (file)
--- a/src/shared/firewall-util.c
+++ b/src/shared/firewall-util.c
@@ -90,6 +90,7 @@ int fw_add_masquerade(
                 const union in_addr_union *destination,
                 unsigned destination_prefixlen) {
 
+        static const xt_chainlabel chain = "POSTROUTING";
         _cleanup_(iptc_freep) struct xtc_handle *h = NULL;
         struct ipt_entry *entry, *mask;
         struct ipt_entry_target *t;
@@ -133,15 +134,15 @@ int fw_add_masquerade(
         memset(mask, 0xFF, sz);
 
         if (add) {
-                if (iptc_check_entry("POSTROUTING", entry, (unsigned char*) mask, h))
+                if (iptc_check_entry(chain, entry, (unsigned char*) mask, h))
                         return 0;
                 if (errno != ENOENT) /* if other error than not existing yet, fail */
                         return -errno;
 
-                if (!iptc_insert_entry("POSTROUTING", entry, 0, h))
+                if (!iptc_insert_entry(chain, entry, 0, h))
                         return -errno;
         } else {
-                if (!iptc_delete_entry("POSTROUTING", entry, (unsigned char*) mask, h)) {
+                if (!iptc_delete_entry(chain, entry, (unsigned char*) mask, h)) {
                         if (errno == ENOENT) /* if it's already gone, all is good! */
                                 return 0;
 
@@ -169,6 +170,7 @@ int fw_add_local_dnat(
                 uint16_t remote_port,
                 const union in_addr_union *previous_remote) {
 
+        static const xt_chainlabel chain_pre = "PREROUTING", chain_output = "OUTPUT";
         _cleanup_(iptc_freep) struct xtc_handle *h = NULL;
         struct ipt_entry *entry, *mask;
         struct ipt_entry_target *t;
@@ -275,11 +277,11 @@ int fw_add_local_dnat(
 
         if (add) {
                 /* Add the PREROUTING rule, if it is missing so far */
-                if (!iptc_check_entry("PREROUTING", entry, (unsigned char*) mask, h)) {
+                if (!iptc_check_entry(chain_pre, entry, (unsigned char*) mask, h)) {
                         if (errno != ENOENT)
                                 return -EINVAL;
 
-                        if (!iptc_insert_entry("PREROUTING", entry, 0, h))
+                        if (!iptc_insert_entry(chain_pre, entry, 0, h))
                                 return -errno;
                 }
 
@@ -287,7 +289,7 @@ int fw_add_local_dnat(
                 if (previous_remote && previous_remote->in.s_addr != remote->in.s_addr) {
                         mr->range[0].min_ip = mr->range[0].max_ip = previous_remote->in.s_addr;
 
-                        if (!iptc_delete_entry("PREROUTING", entry, (unsigned char*) mask, h)) {
+                        if (!iptc_delete_entry(chain_pre, entry, (unsigned char*) mask, h)) {
                                 if (errno != ENOENT)
                                         return -errno;
                         }
@@ -305,11 +307,11 @@ int fw_add_local_dnat(
                                 entry->ip.invflags = IPT_INV_DSTIP;
                         }
 
-                        if (!iptc_check_entry("OUTPUT", entry, (unsigned char*) mask, h)) {
+                        if (!iptc_check_entry(chain_output, entry, (unsigned char*) mask, h)) {
                                 if (errno != ENOENT)
                                         return -errno;
 
-                                if (!iptc_insert_entry("OUTPUT", entry, 0, h))
+                                if (!iptc_insert_entry(chain_output, entry, 0, h))
                                         return -errno;
                         }
 
@@ -317,14 +319,14 @@ int fw_add_local_dnat(
                         if (previous_remote && previous_remote->in.s_addr != remote->in.s_addr) {
                                 mr->range[0].min_ip = mr->range[0].max_ip = previous_remote->in.s_addr;
 
-                                if (!iptc_delete_entry("OUTPUT", entry, (unsigned char*) mask, h)) {
+                                if (!iptc_delete_entry(chain_output, entry, (unsigned char*) mask, h)) {
                                         if (errno != ENOENT)
                                                 return -errno;
                                 }
                         }
                 }
         } else {
-                if (!iptc_delete_entry("PREROUTING", entry, (unsigned char*) mask, h)) {
+                if (!iptc_delete_entry(chain_pre, entry, (unsigned char*) mask, h)) {
                         if (errno != ENOENT)
                                 return -errno;
                 }
@@ -336,7 +338,7 @@ int fw_add_local_dnat(
                                 entry->ip.invflags = IPT_INV_DSTIP;
                         }
 
-                        if (!iptc_delete_entry("OUTPUT", entry, (unsigned char*) mask, h)) {
+                        if (!iptc_delete_entry(chain_output, entry, (unsigned char*) mask, h)) {
                                 if (errno != ENOENT)
                                         return -errno;
                         }