Mark a couple of parameters as const in the public API

docs/ares_init_options.3

@@ -48,7 +48,7 @@ struct ares_options {
 };
 
 int ares_init_options(ares_channel_t **\fIchannelptr\fP,
-                      struct ares_options *\fIoptions\fP,
+                      const struct ares_options *\fIoptions\fP,
                       int \fIoptmask\fP)
 .fi
 .SH DESCRIPTION

docs/ares_set_servers.3

@@ -24,10 +24,10 @@ for an ares channel.
 #include <ares.h>
 
 int ares_set_servers(ares_channel_t *\fIchannel\fP,
-                     struct ares_addr_node *\fIservers\fP)
+                     const struct ares_addr_node *\fIservers\fP)
 
 int ares_set_servers_ports(ares_channel_t *\fIchannel\fP,
-                           struct ares_addr_port_node *\fIservers\fP)
+                           const struct ares_addr_port_node *\fIservers\fP)
 .fi
 .SH DESCRIPTION
 The \fBares_set_servers(3)\fP function initializes name servers configuration

include/ares.h

@@ -360,7 +360,8 @@ CARES_EXTERN const char *ares_version(int *version);
 CARES_EXTERN int         ares_init(ares_channel_t **channelptr);
 
 CARES_EXTERN int         ares_init_options(ares_channel_t     **channelptr,
-                                           struct ares_options *options, int optmask);
+                                           const struct ares_options *options,
+                                           int optmask);
 
 CARES_EXTERN int         ares_save_options(ares_channel_t      *channel,
                                            struct ares_options *options, int *optmask);
@@ -702,10 +703,10 @@ struct ares_addr_port_node {
   int tcp_port;
 };
 
-CARES_EXTERN int         ares_set_servers(ares_channel_t        *channel,
-                                          struct ares_addr_node *servers);
+CARES_EXTERN int         ares_set_servers(ares_channel_t *channel,
+                                          const struct ares_addr_node *servers);
 CARES_EXTERN int         ares_set_servers_ports(ares_channel_t             *channel,
-                                                struct ares_addr_port_node *servers);
+                                                const struct ares_addr_port_node *servers);
 
 /* Incomming string format: host[:port][,host[:port]]... */
 CARES_EXTERN int         ares_set_servers_csv(ares_channel_t *channel,

src/lib/ares_init.c

@@ -286,8 +286,8 @@ error:
   return rc;
 }
 
-int ares_init_options(ares_channel_t **channelptr, struct ares_options *options,
-                      int optmask)
+int ares_init_options(ares_channel_t **channelptr,
+                      const struct ares_options *options, int optmask)
 {
   ares_channel_t *channel;
   ares_status_t   status = ARES_SUCCESS;

src/lib/ares_update_servers.c

@@ -832,7 +832,8 @@ int ares_get_servers_ports(ares_channel_t              *channel,
   return (int)status;
 }
 
-int ares_set_servers(ares_channel_t *channel, struct ares_addr_node *servers)
+int ares_set_servers(ares_channel_t              *channel,
+                     const struct ares_addr_node *servers)
 {
   ares__llist_t *slist;
   ares_status_t  status;
@@ -853,8 +854,8 @@ int ares_set_servers(ares_channel_t *channel, struct ares_addr_node *servers)
   return (int)status;
 }
 
-int ares_set_servers_ports(ares_channel_t             *channel,
-                           struct ares_addr_port_node *servers)
+int ares_set_servers_ports(ares_channel_t                   *channel,
+                           const struct ares_addr_port_node *servers)
 {
   ares__llist_t *slist;
   ares_status_t  status;