Index: uspace/lib/c/include/inet/addr.h
===================================================================
--- uspace/lib/c/include/inet/addr.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/addr.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -112,9 +112,9 @@
 extern int inet_naddr_compare_mask(const inet_naddr_t *, const inet_addr_t *);
 
-extern int inet_addr_parse(const char *, inet_addr_t *, char **);
-extern int inet_naddr_parse(const char *, inet_naddr_t *, char **);
+extern errno_t inet_addr_parse(const char *, inet_addr_t *, char **);
+extern errno_t inet_naddr_parse(const char *, inet_naddr_t *, char **);
 
-extern int inet_addr_format(const inet_addr_t *, char **);
-extern int inet_naddr_format(const inet_naddr_t *, char **);
+extern errno_t inet_addr_format(const inet_addr_t *, char **);
+extern errno_t inet_naddr_format(const inet_naddr_t *, char **);
 
 extern ip_ver_t inet_addr_get(const inet_addr_t *, addr32_t *, addr128_t *);
Index: uspace/lib/c/include/inet/dhcp.h
===================================================================
--- uspace/lib/c/include/inet/dhcp.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/dhcp.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -38,8 +38,8 @@
 #include <types/common.h>
 
-extern int dhcp_init(void);
-extern int dhcp_link_add(sysarg_t);
-extern int dhcp_link_remove(sysarg_t);
-extern int dhcp_discover(sysarg_t);
+extern errno_t dhcp_init(void);
+extern errno_t dhcp_link_add(sysarg_t);
+extern errno_t dhcp_link_remove(sysarg_t);
+extern errno_t dhcp_discover(sysarg_t);
 
 #endif
Index: uspace/lib/c/include/inet/dnsr.h
===================================================================
--- uspace/lib/c/include/inet/dnsr.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/dnsr.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -50,9 +50,9 @@
 } dnsr_hostinfo_t;
 
-extern int dnsr_init(void);
-extern int dnsr_name2host(const char *, dnsr_hostinfo_t **, ip_ver_t);
+extern errno_t dnsr_init(void);
+extern errno_t dnsr_name2host(const char *, dnsr_hostinfo_t **, ip_ver_t);
 extern void dnsr_hostinfo_destroy(dnsr_hostinfo_t *);
-extern int dnsr_get_srvaddr(inet_addr_t *);
-extern int dnsr_set_srvaddr(inet_addr_t *);
+extern errno_t dnsr_get_srvaddr(inet_addr_t *);
+extern errno_t dnsr_set_srvaddr(inet_addr_t *);
 
 #endif
Index: uspace/lib/c/include/inet/host.h
===================================================================
--- uspace/lib/c/include/inet/host.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/host.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -40,9 +40,9 @@
 #include <types/inet/hostport.h>
 
-extern int inet_host_parse(const char *, inet_host_t **, char **);
-extern int inet_host_format(inet_host_t *, char **);
+extern errno_t inet_host_parse(const char *, inet_host_t **, char **);
+extern errno_t inet_host_format(inet_host_t *, char **);
 extern void inet_host_destroy(inet_host_t *);
-extern int inet_host_lookup_one(inet_host_t *, ip_ver_t, inet_addr_t *);
-extern int inet_host_plookup_one(const char *, ip_ver_t, inet_addr_t *,
+extern errno_t inet_host_lookup_one(inet_host_t *, ip_ver_t, inet_addr_t *);
+extern errno_t inet_host_plookup_one(const char *, ip_ver_t, inet_addr_t *,
     char **, const char **);
 
Index: uspace/lib/c/include/inet/hostname.h
===================================================================
--- uspace/lib/c/include/inet/hostname.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/hostname.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -36,5 +36,5 @@
 #define LIBC_INET_HOSTNAME_H_
 
-extern int inet_hostname_parse(const char *, char **, char **);
+extern errno_t inet_hostname_parse(const char *, char **, char **);
 
 #endif
Index: uspace/lib/c/include/inet/hostport.h
===================================================================
--- uspace/lib/c/include/inet/hostport.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/hostport.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -40,9 +40,9 @@
 #include <types/inet/hostport.h>
 
-extern int inet_hostport_parse(const char *, inet_hostport_t **, char **);
-extern int inet_hostport_format(inet_hostport_t *, char **);
+extern errno_t inet_hostport_parse(const char *, inet_hostport_t **, char **);
+extern errno_t inet_hostport_format(inet_hostport_t *, char **);
 extern void inet_hostport_destroy(inet_hostport_t *);
-extern int inet_hostport_lookup_one(inet_hostport_t *, ip_ver_t, inet_ep_t *);
-extern int inet_hostport_plookup_one(const char *, ip_ver_t, inet_ep_t *,
+extern errno_t inet_hostport_lookup_one(inet_hostport_t *, ip_ver_t, inet_ep_t *);
+extern errno_t inet_hostport_plookup_one(const char *, ip_ver_t, inet_ep_t *,
     char **, const char **);
 
Index: uspace/lib/c/include/inet/inet.h
===================================================================
--- uspace/lib/c/include/inet/inet.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/inet.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -41,7 +41,7 @@
 #include <types/inet.h>
 
-extern int inet_init(uint8_t, inet_ev_ops_t *);
-extern int inet_send(inet_dgram_t *, uint8_t, inet_df_t);
-extern int inet_get_srcaddr(inet_addr_t *, uint8_t, inet_addr_t *);
+extern errno_t inet_init(uint8_t, inet_ev_ops_t *);
+extern errno_t inet_send(inet_dgram_t *, uint8_t, inet_df_t);
+extern errno_t inet_get_srcaddr(inet_addr_t *, uint8_t, inet_addr_t *);
 
 #endif
Index: uspace/lib/c/include/inet/inetcfg.h
===================================================================
--- uspace/lib/c/include/inet/inetcfg.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/inetcfg.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -40,20 +40,20 @@
 #include <types/inetcfg.h>
 
-extern int inetcfg_init(void);
-extern int inetcfg_addr_create_static(const char *, inet_naddr_t *, sysarg_t, sysarg_t *);
-extern int inetcfg_addr_delete(sysarg_t);
-extern int inetcfg_addr_get(sysarg_t, inet_addr_info_t *);
-extern int inetcfg_addr_get_id(const char *, sysarg_t, sysarg_t *);
-extern int inetcfg_get_addr_list(sysarg_t **, size_t *);
-extern int inetcfg_get_link_list(sysarg_t **, size_t *);
-extern int inetcfg_get_sroute_list(sysarg_t **, size_t *);
-extern int inetcfg_link_add(sysarg_t);
-extern int inetcfg_link_get(sysarg_t, inet_link_info_t *);
-extern int inetcfg_link_remove(sysarg_t);
-extern int inetcfg_sroute_get(sysarg_t, inet_sroute_info_t *);
-extern int inetcfg_sroute_get_id(const char *, sysarg_t *);
-extern int inetcfg_sroute_create(const char *, inet_naddr_t *, inet_addr_t *,
+extern errno_t inetcfg_init(void);
+extern errno_t inetcfg_addr_create_static(const char *, inet_naddr_t *, sysarg_t, sysarg_t *);
+extern errno_t inetcfg_addr_delete(sysarg_t);
+extern errno_t inetcfg_addr_get(sysarg_t, inet_addr_info_t *);
+extern errno_t inetcfg_addr_get_id(const char *, sysarg_t, sysarg_t *);
+extern errno_t inetcfg_get_addr_list(sysarg_t **, size_t *);
+extern errno_t inetcfg_get_link_list(sysarg_t **, size_t *);
+extern errno_t inetcfg_get_sroute_list(sysarg_t **, size_t *);
+extern errno_t inetcfg_link_add(sysarg_t);
+extern errno_t inetcfg_link_get(sysarg_t, inet_link_info_t *);
+extern errno_t inetcfg_link_remove(sysarg_t);
+extern errno_t inetcfg_sroute_get(sysarg_t, inet_sroute_info_t *);
+extern errno_t inetcfg_sroute_get_id(const char *, sysarg_t *);
+extern errno_t inetcfg_sroute_create(const char *, inet_naddr_t *, inet_addr_t *,
     sysarg_t *);
-extern int inetcfg_sroute_delete(sysarg_t);
+extern errno_t inetcfg_sroute_delete(sysarg_t);
 
 #endif
Index: uspace/lib/c/include/inet/inetping.h
===================================================================
--- uspace/lib/c/include/inet/inetping.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/inetping.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -40,10 +40,10 @@
 
 typedef struct inetping_ev_ops {
-	int (*recv)(inetping_sdu_t *);
+	errno_t (*recv)(inetping_sdu_t *);
 } inetping_ev_ops_t;
 
-extern int inetping_init(inetping_ev_ops_t *);
-extern int inetping_send(inetping_sdu_t *);
-extern int inetping_get_srcaddr(const inet_addr_t *, inet_addr_t *);
+extern errno_t inetping_init(inetping_ev_ops_t *);
+extern errno_t inetping_send(inetping_sdu_t *);
+extern errno_t inetping_get_srcaddr(const inet_addr_t *, inet_addr_t *);
 
 #endif
Index: uspace/lib/c/include/inet/iplink.h
===================================================================
--- uspace/lib/c/include/inet/iplink.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/iplink.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -78,17 +78,17 @@
 
 typedef struct iplink_ev_ops {
-	int (*recv)(iplink_t *, iplink_recv_sdu_t *, ip_ver_t);
-	int (*change_addr)(iplink_t *, addr48_t);
+	errno_t (*recv)(iplink_t *, iplink_recv_sdu_t *, ip_ver_t);
+	errno_t (*change_addr)(iplink_t *, addr48_t);
 } iplink_ev_ops_t;
 
-extern int iplink_open(async_sess_t *, iplink_ev_ops_t *, void *, iplink_t **);
+extern errno_t iplink_open(async_sess_t *, iplink_ev_ops_t *, void *, iplink_t **);
 extern void iplink_close(iplink_t *);
-extern int iplink_send(iplink_t *, iplink_sdu_t *);
-extern int iplink_send6(iplink_t *, iplink_sdu6_t *);
-extern int iplink_addr_add(iplink_t *, inet_addr_t *);
-extern int iplink_addr_remove(iplink_t *, inet_addr_t *);
-extern int iplink_get_mtu(iplink_t *, size_t *);
-extern int iplink_get_mac48(iplink_t *, addr48_t *);
-extern int iplink_set_mac48(iplink_t *, addr48_t);
+extern errno_t iplink_send(iplink_t *, iplink_sdu_t *);
+extern errno_t iplink_send6(iplink_t *, iplink_sdu6_t *);
+extern errno_t iplink_addr_add(iplink_t *, inet_addr_t *);
+extern errno_t iplink_addr_remove(iplink_t *, inet_addr_t *);
+extern errno_t iplink_get_mtu(iplink_t *, size_t *);
+extern errno_t iplink_get_mac48(iplink_t *, addr48_t *);
+extern errno_t iplink_set_mac48(iplink_t *, addr48_t);
 extern void *iplink_get_userptr(iplink_t *);
 
Index: uspace/lib/c/include/inet/iplink_srv.h
===================================================================
--- uspace/lib/c/include/inet/iplink_srv.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/iplink_srv.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -53,20 +53,20 @@
 
 typedef struct iplink_ops {
-	int (*open)(iplink_srv_t *);
-	int (*close)(iplink_srv_t *);
-	int (*send)(iplink_srv_t *, iplink_sdu_t *);
-	int (*send6)(iplink_srv_t *, iplink_sdu6_t *);
-	int (*get_mtu)(iplink_srv_t *, size_t *);
-	int (*get_mac48)(iplink_srv_t *, addr48_t *);
-	int (*set_mac48)(iplink_srv_t *, addr48_t *);
-	int (*addr_add)(iplink_srv_t *, inet_addr_t *);
-	int (*addr_remove)(iplink_srv_t *, inet_addr_t *);
+	errno_t (*open)(iplink_srv_t *);
+	errno_t (*close)(iplink_srv_t *);
+	errno_t (*send)(iplink_srv_t *, iplink_sdu_t *);
+	errno_t (*send6)(iplink_srv_t *, iplink_sdu6_t *);
+	errno_t (*get_mtu)(iplink_srv_t *, size_t *);
+	errno_t (*get_mac48)(iplink_srv_t *, addr48_t *);
+	errno_t (*set_mac48)(iplink_srv_t *, addr48_t *);
+	errno_t (*addr_add)(iplink_srv_t *, inet_addr_t *);
+	errno_t (*addr_remove)(iplink_srv_t *, inet_addr_t *);
 } iplink_ops_t;
 
 extern void iplink_srv_init(iplink_srv_t *);
 
-extern int iplink_conn(ipc_callid_t, ipc_call_t *, void *);
-extern int iplink_ev_recv(iplink_srv_t *, iplink_recv_sdu_t *, ip_ver_t);
-extern int iplink_ev_change_addr(iplink_srv_t *, addr48_t *);
+extern errno_t iplink_conn(ipc_callid_t, ipc_call_t *, void *);
+extern errno_t iplink_ev_recv(iplink_srv_t *, iplink_recv_sdu_t *, ip_ver_t);
+extern errno_t iplink_ev_change_addr(iplink_srv_t *, addr48_t *);
 
 #endif
Index: uspace/lib/c/include/inet/tcp.h
===================================================================
--- uspace/lib/c/include/inet/tcp.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/tcp.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -98,23 +98,23 @@
 } tcp_t;
 
-extern int tcp_create(tcp_t **);
+extern errno_t tcp_create(tcp_t **);
 extern void tcp_destroy(tcp_t *);
-extern int tcp_conn_create(tcp_t *, inet_ep2_t *, tcp_cb_t *, void *,
+extern errno_t tcp_conn_create(tcp_t *, inet_ep2_t *, tcp_cb_t *, void *,
     tcp_conn_t **);
 extern void tcp_conn_destroy(tcp_conn_t *);
 extern void *tcp_conn_userptr(tcp_conn_t *);
-extern int tcp_listener_create(tcp_t *, inet_ep_t *, tcp_listen_cb_t *, void *,
+extern errno_t tcp_listener_create(tcp_t *, inet_ep_t *, tcp_listen_cb_t *, void *,
     tcp_cb_t *, void *, tcp_listener_t **);
 extern void tcp_listener_destroy(tcp_listener_t *);
 extern void *tcp_listener_userptr(tcp_listener_t *);
 
-extern int tcp_conn_wait_connected(tcp_conn_t *);
-extern int tcp_conn_send(tcp_conn_t *, const void *, size_t);
-extern int tcp_conn_send_fin(tcp_conn_t *);
-extern int tcp_conn_push(tcp_conn_t *);
-extern int tcp_conn_reset(tcp_conn_t *);
+extern errno_t tcp_conn_wait_connected(tcp_conn_t *);
+extern errno_t tcp_conn_send(tcp_conn_t *, const void *, size_t);
+extern errno_t tcp_conn_send_fin(tcp_conn_t *);
+extern errno_t tcp_conn_push(tcp_conn_t *);
+extern errno_t tcp_conn_reset(tcp_conn_t *);
 
-extern int tcp_conn_recv(tcp_conn_t *, void *, size_t, size_t *);
-extern int tcp_conn_recv_wait(tcp_conn_t *, void *, size_t, size_t *);
+extern errno_t tcp_conn_recv(tcp_conn_t *, void *, size_t, size_t *);
+extern errno_t tcp_conn_recv_wait(tcp_conn_t *, void *, size_t, size_t *);
 
 
Index: uspace/lib/c/include/inet/udp.h
===================================================================
--- uspace/lib/c/include/inet/udp.h	(revision 36f0738ce13f32ad07d7932ca18f677cab815660)
+++ uspace/lib/c/include/inet/udp.h	(revision c718bdada0e16b36b6f0f68df54a3ee343f91e49)
@@ -91,14 +91,14 @@
 } udp_t;
 
-extern int udp_create(udp_t **);
+extern errno_t udp_create(udp_t **);
 extern void udp_destroy(udp_t *);
-extern int udp_assoc_create(udp_t *, inet_ep2_t *, udp_cb_t *, void *,
+extern errno_t udp_assoc_create(udp_t *, inet_ep2_t *, udp_cb_t *, void *,
     udp_assoc_t **);
-extern int udp_assoc_set_nolocal(udp_assoc_t *);
+extern errno_t udp_assoc_set_nolocal(udp_assoc_t *);
 extern void udp_assoc_destroy(udp_assoc_t *);
-extern int udp_assoc_send_msg(udp_assoc_t *, inet_ep_t *, void *, size_t);
+extern errno_t udp_assoc_send_msg(udp_assoc_t *, inet_ep_t *, void *, size_t);
 extern void *udp_assoc_userptr(udp_assoc_t *);
 extern size_t udp_rmsg_size(udp_rmsg_t *);
-extern int udp_rmsg_read(udp_rmsg_t *, size_t, void *, size_t);
+extern errno_t udp_rmsg_read(udp_rmsg_t *, size_t, void *, size_t);
 extern void udp_rmsg_remote_ep(udp_rmsg_t *, inet_ep_t *);
 extern uint8_t udp_rerr_type(udp_rerr_t *);