Fix constness warnings

Fix the following GCC warnings:

  src/ncsi.c: In function ‘ncsi_input’:
  src/ncsi.c:139:31: error: cast discards ‘const’ qualifier from pointer target type [-Werror=cast-qual]
    139 |     struct ncsi_pkt_hdr *nh = (struct ncsi_pkt_hdr *)(pkt + ETH_HLEN);
        |                               ^
  src/dnssearch.c: In function ‘translate_dnssearch’:
  src/dnssearch.c:242:33: error: cast discards ‘const’ qualifier from pointer target type [-Werror=cast-qual]
    242 |     num_domains = g_strv_length((GStrv)names);
        |                                 ^
  src/slirp.c: In function ‘arp_input’:
  src/slirp.c:747:31: error: cast discards ‘const’ qualifier from pointer target type [-Werror=cast-qual]
    747 |     struct slirp_arphdr *ah = (struct slirp_arphdr *)(pkt + ETH_HLEN);
        |                               ^
  src/dnssearch.c: In function ‘translate_dnssearch’:
  src/dnssearch.c:242:33: error: cast discards ‘const’ qualifier from pointer target type [-Werror=cast-qual]
    242 |     num_domains = g_strv_length((const GStrv)names);
        |                                 ^
  src/slirp.c: In function ‘arp_input’:
  src/slirp.c:764:48: error: passing argument 3 of ‘arp_table_add’ discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
    764 |             arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
        |                                              ~~^~~~~~~~
  In file included from src/slirp.c:25:
  src/slirp.h:101:60: note: expected ‘uint8_t *’ {aka ‘unsigned char *’} but argument is of type ‘const unsigned char *’
    101 | void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN]);
        |                                                    ~~~~~~~~^~~~~~~~~~~~~~~~~
  src/slirp.c:783:48: error: passing argument 3 of ‘arp_table_add’ discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
    783 |             arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
        |                                              ~~^~~~~~~~
  In file included from src/slirp.c:25:
  src/slirp.h:101:60: note: expected ‘uint8_t *’ {aka ‘unsigned char *’} but argument is of type ‘const unsigned char *’
    101 | void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN]);
        |                                                    ~~~~~~~~^~~~~~~~~~~~~~~~~
  src/slirp.c:804:44: error: passing argument 3 of ‘arp_table_add’ discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
    804 |         arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
        |                                          ~~^~~~~~~~
  In file included from src/slirp.c:25:
  src/slirp.h:101:60: note: expected ‘uint8_t *’ {aka ‘unsigned char *’} but argument is of type ‘const unsigned char *’
    101 | void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN]);
        |                                                    ~~~~~~~~^~~~~~~~~~~~~~~~~

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

5 files changed, 9 insertions, 5 deletions

diff --git a/src/arp_table.c b/src/arp_table.c
index 054fbf5..959e5b9 100644
--- a/src/arp_table.c
+++ b/src/arp_table.c
@@ -27,7 +27,8 @@
 
 #include <string.h>
 
-void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN])
+void arp_table_add(Slirp *slirp, uint32_t ip_addr,
+                   const uint8_t ethaddr[ETH_ALEN])
 {
     const uint32_t broadcast_addr =
         ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
diff --git a/src/dnssearch.c b/src/dnssearch.c
index e8f14e3..55497e8 100644
--- a/src/dnssearch.c
+++ b/src/dnssearch.c
@@ -239,7 +239,7 @@ int translate_dnssearch(Slirp *s, const char **names)
     uint8_t *result = NULL, *outptr;
     CompactDomain *domains = NULL;
 
-    num_domains = g_strv_length((GStrv)names);
+    num_domains = g_strv_length((GStrv)(void *)names);
     if (num_domains == 0) {
         return -2;
     }
diff --git a/src/ncsi.c b/src/ncsi.c
index ddd980d..3c1dfef 100644
--- a/src/ncsi.c
+++ b/src/ncsi.c
@@ -136,7 +136,8 @@ static const struct ncsi_rsp_handler {
 
 void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
 {
-    struct ncsi_pkt_hdr *nh = (struct ncsi_pkt_hdr *)(pkt + ETH_HLEN);
+    const struct ncsi_pkt_hdr *nh =
+        (const struct ncsi_pkt_hdr *)(pkt + ETH_HLEN);
     uint8_t ncsi_reply[ETH_HLEN + NCSI_MAX_LEN];
     struct ethhdr *reh = (struct ethhdr *)ncsi_reply;
     struct ncsi_rsp_pkt_hdr *rnh =
diff --git a/src/slirp.c b/src/slirp.c
index 4053d34..aa1b74d 100644
--- a/src/slirp.c
+++ b/src/slirp.c
@@ -751,7 +751,8 @@ void slirp_pollfds_poll(Slirp *slirp, int select_error,
 
 static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
 {
-    struct slirp_arphdr *ah = (struct slirp_arphdr *)(pkt + ETH_HLEN);
+    const struct slirp_arphdr *ah =
+        (const struct slirp_arphdr *)(pkt + ETH_HLEN);
     uint8_t arp_reply[MAX(ETH_HLEN + sizeof(struct slirp_arphdr), 64)];
     struct ethhdr *reh = (struct ethhdr *)arp_reply;
     struct slirp_arphdr *rah = (struct slirp_arphdr *)(arp_reply + ETH_HLEN);
diff --git a/src/slirp.h b/src/slirp.h
index 47d861b..4f8b133 100644
--- a/src/slirp.h
+++ b/src/slirp.h
@@ -98,7 +98,8 @@ typedef struct ArpTable {
     int next_victim;
 } ArpTable;
 
-void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN]);
+void arp_table_add(Slirp *slirp, uint32_t ip_addr,
+                   const uint8_t ethaddr[ETH_ALEN]);
 
 bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
                       uint8_t out_ethaddr[ETH_ALEN]);