From 702d8b0c5bbbe5b02f5bc5ff9637009afbd70399 Mon Sep 17 00:00:00 2001
From: "Nicholas J. Kain" <nicholas@kain.us>
Date: Fri, 13 Feb 2015 23:14:08 -0500
Subject: [PATCH] Mark pointer arguments that cannot ever be null as [static
 1].

Also constify some cases, too.
---
 src/arp.c          | 28 +++++++++++++--------
 src/arp.h          |  3 ++-
 src/cfg.rl         |  2 +-
 src/dhcp.c         | 17 +++++++------
 src/duiaid.c       | 22 ++++++++--------
 src/duiaid.h       |  3 ++-
 src/ifchange.c     | 37 +++++++++++++++++----------
 src/ifchange.h     |  3 ++-
 src/ifchd-parse.h  |  2 +-
 src/ifchd-parse.rl |  2 +-
 src/ifchd.c        | 22 ++++++++--------
 src/ifchd.h        | 16 ++++++------
 src/ndhc.c         |  6 ++---
 src/ndhc.h         |  4 +--
 src/options.c      | 62 ++++++++++++++++++++++++----------------------
 src/options.h      | 51 +++++++++++++++++++-------------------
 src/state.c        | 17 +++++++------
 src/state.h        |  5 ++--
 src/sys.c          |  2 +-
 src/sys.h          |  2 +-
 20 files changed, 169 insertions(+), 137 deletions(-)

diff --git a/src/arp.c b/src/arp.c
index 3754797..db32c64 100644
--- a/src/arp.c
+++ b/src/arp.c
@@ -209,7 +209,8 @@ static void arp_min_close_fd(struct client_state_t cs[static 1])
     garp.state = AS_NONE;
 }
 
-static void arp_switch_state(struct client_state_t cs[static 1], arp_state_t state)
+static void arp_switch_state(struct client_state_t cs[static 1],
+                             arp_state_t state)
 {
     if (garp.state == state || garp.state >= AS_MAX)
         return;
@@ -242,7 +243,8 @@ static void arp_reopen_fd(struct client_state_t cs[static 1])
     arp_switch_state(cs, prev_state);
 }
 
-static int arp_send(struct client_state_t cs[static 1], struct arpMsg *arp)
+static int arp_send(struct client_state_t cs[static 1],
+                    struct arpMsg arp[static 1])
 {
     struct sockaddr_ll addr = {
         .sll_family = AF_PACKET,
@@ -305,7 +307,8 @@ static int arp_ping(struct client_state_t cs[static 1], uint32_t test_ip)
 }
 
 // Returns 0 on success, -1 on failure.
-static int arp_ip_anon_ping(struct client_state_t cs[static 1], uint32_t test_ip)
+static int arp_ip_anon_ping(struct client_state_t cs[static 1],
+                            uint32_t test_ip)
 {
     BASE_ARPMSG();
     memcpy(arp.dip4, &test_ip, sizeof test_ip);
@@ -332,7 +335,8 @@ static int arp_announcement(struct client_state_t cs[static 1])
 #undef BASE_ARPMSG
 
 // Callable from DS_REQUESTING, DS_RENEWING, or DS_REBINDING via an_packet()
-int arp_check(struct client_state_t cs[static 1], struct dhcpmsg *packet)
+int arp_check(struct client_state_t cs[static 1],
+              struct dhcpmsg packet[static 1])
 {
     memcpy(&garp.dhcp_packet, packet, sizeof (struct dhcpmsg));
     arp_switch_state(cs, AS_COLLISION_CHECK);
@@ -509,7 +513,7 @@ static int arp_validate_bpf(struct arpMsg *am)
 // ARP validation functions that will be performed by the BPF if it is
 // installed.
 static int arp_validate_bpf_defense(struct client_state_t cs[static 1],
-                                    struct arpMsg *am)
+                                    struct arpMsg am[static 1])
 {
     if (memcmp(am->sip4, &cs->clientAddr, 4))
         return 0;
@@ -518,7 +522,7 @@ static int arp_validate_bpf_defense(struct client_state_t cs[static 1],
     return 1;
 }
 
-static int arp_is_query_reply(struct arpMsg *am)
+static int arp_is_query_reply(struct arpMsg am[static 1])
 {
     if (am->operation != htons(ARPOP_REPLY))
         return 0;
@@ -536,7 +540,8 @@ static int arp_gen_probe_wait(struct client_state_t cs[static 1])
         % (arp_probe_max - arp_probe_min);
 }
 
-static void arp_defense_timeout(struct client_state_t cs[static 1], long long nowts)
+static void arp_defense_timeout(struct client_state_t cs[static 1],
+                                long long nowts)
 {
     (void)nowts; // Suppress warning; parameter necessary but unused.
     if (garp.wake_ts[AS_DEFENSE] != -1) {
@@ -546,7 +551,8 @@ static void arp_defense_timeout(struct client_state_t cs[static 1], long long no
     }
 }
 
-static void arp_gw_check_timeout(struct client_state_t cs[static 1], long long nowts)
+static void arp_gw_check_timeout(struct client_state_t cs[static 1],
+                                 long long nowts)
 {
     arp_defense_timeout(cs, nowts);
 
@@ -582,7 +588,8 @@ static void arp_do_gw_query_done(struct client_state_t cs[static 1])
     arp_announcement(cs);  // Do a second announcement.
 }
 
-static void arp_gw_query_timeout(struct client_state_t cs[static 1], long long nowts)
+static void arp_gw_query_timeout(struct client_state_t cs[static 1],
+                                 long long nowts)
 {
     arp_defense_timeout(cs, nowts);
 
@@ -609,7 +616,8 @@ static void arp_gw_query_timeout(struct client_state_t cs[static 1], long long n
         garp.send_stats[ASEND_GW_PING].ts + ARP_RETRANS_DELAY;
 }
 
-static void arp_collision_timeout(struct client_state_t cs[static 1], long long nowts)
+static void arp_collision_timeout(struct client_state_t cs[static 1],
+                                  long long nowts)
 {
     arp_defense_timeout(cs, nowts);
 
diff --git a/src/arp.h b/src/arp.h
index 7754c81..38de05a 100644
--- a/src/arp.h
+++ b/src/arp.h
@@ -61,7 +61,8 @@ extern int arp_probe_max;
 void set_arp_relentless_def(bool v);
 void arp_reset_send_stats(void);
 void arp_close_fd(struct client_state_t cs[static 1]);
-int arp_check(struct client_state_t cs[static 1], struct dhcpmsg *packet);
+int arp_check(struct client_state_t cs[static 1],
+              struct dhcpmsg packet[static 1]);
 int arp_gw_check(struct client_state_t cs[static 1]);
 void arp_set_defense_mode(struct client_state_t cs[static 1]);
 void arp_success(struct client_state_t cs[static 1]);
diff --git a/src/cfg.rl b/src/cfg.rl
index d83b495..f3fa1b1 100644
--- a/src/cfg.rl
+++ b/src/cfg.rl
@@ -224,7 +224,7 @@ struct cfgparse {
 
 %% write data;
 
-static void parse_cfgfile(const char *fname)
+static void parse_cfgfile(const char fname[static 1])
 {
     struct cfgparse ccfg;
     memset(&ccfg, 0, sizeof ccfg);
diff --git a/src/dhcp.c b/src/dhcp.c
index 6a5d9eb..2c4dff6 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -78,7 +78,7 @@ static int get_raw_listen_socket(struct client_state_t cs[static 1])
 
 // Unicast a DHCP message using a UDP socket.
 static ssize_t send_dhcp_unicast(struct client_state_t cs[static 1],
-                                 struct dhcpmsg *payload)
+                                 struct dhcpmsg payload[static 1])
 {
     ssize_t ret = -1;
     int fd = get_udp_unicast_socket(cs);
@@ -124,13 +124,13 @@ static ssize_t send_dhcp_unicast(struct client_state_t cs[static 1],
 }
 
 // Returns 1 if IP checksum is correct, otherwise 0.
-static int ip_checksum(struct ip_udp_dhcp_packet *packet)
+static int ip_checksum(struct ip_udp_dhcp_packet packet[static 1])
 {
     return net_checksum161c(&packet->ip, sizeof packet->ip) == 0;
 }
 
 // Returns 1 if UDP checksum is correct, otherwise 0.
-static int udp_checksum(struct ip_udp_dhcp_packet *packet)
+static int udp_checksum(struct ip_udp_dhcp_packet packet[static 1])
 {
     struct iphdr ph = {
         .saddr = packet->ip.saddr,
@@ -147,7 +147,7 @@ static int udp_checksum(struct ip_udp_dhcp_packet *packet)
     return cs == 0;
 }
 
-static int get_raw_packet_validate_bpf(struct ip_udp_dhcp_packet *packet)
+static int get_raw_packet_validate_bpf(struct ip_udp_dhcp_packet packet[static 1])
 {
     if (packet->ip.version != IPVERSION) {
         log_warning("%s: IP version is not IPv4.", client_config.interface);
@@ -180,7 +180,7 @@ static int get_raw_packet_validate_bpf(struct ip_udp_dhcp_packet *packet)
 // Read a packet from a raw socket.  Returns -1 on fatal error, -2 on
 // transient error.
 static ssize_t get_raw_packet(struct client_state_t cs[static 1],
-                              struct dhcpmsg *payload,
+                              struct dhcpmsg payload[static 1],
                               uint32_t *srcaddr)
 {
     struct ip_udp_dhcp_packet packet;
@@ -244,7 +244,7 @@ int check_carrier(int fd)
 }
 
 // Broadcast a DHCP message using a raw socket.
-static ssize_t send_dhcp_raw(struct dhcpmsg *payload)
+static ssize_t send_dhcp_raw(struct dhcpmsg payload[static 1])
 {
     ssize_t ret = -1;
     int fd = get_raw_broadcast_socket();
@@ -341,8 +341,9 @@ void stop_dhcp_listen(struct client_state_t cs[static 1])
     cs->listenFd = -1;
 }
 
-static int validate_dhcp_packet(struct client_state_t cs[static 1], size_t len,
-                                struct dhcpmsg *packet, uint8_t *msgtype)
+static int validate_dhcp_packet(struct client_state_t cs[static 1],
+                                size_t len, struct dhcpmsg packet[static 1],
+                                uint8_t *msgtype)
 {
     if (len < offsetof(struct dhcpmsg, options)) {
         log_warning("%s: Packet is too short to contain magic cookie.  Ignoring.",
diff --git a/src/duiaid.c b/src/duiaid.c
index e7d2d89..d1ed3af 100644
--- a/src/duiaid.c
+++ b/src/duiaid.c
@@ -41,7 +41,7 @@
 #include "duiaid.h"
 #include "ndhc.h"
 
-static void get_duid_path(char *duidfile, size_t dlen)
+static void get_duid_path(char duidfile[static 1], size_t dlen)
 {
     int splen = snprintf(duidfile, dlen, "%s/DUID", state_dir);
     if (splen < 0)
@@ -51,8 +51,8 @@ static void get_duid_path(char *duidfile, size_t dlen)
                 __func__, splen, sizeof dlen);
 }
 
-static void get_iaid_path(char *iaidfile, size_t ilen, uint8_t *hwaddr,
-                          size_t hwaddrlen)
+static void get_iaid_path(char iaidfile[static 1], size_t ilen,
+                          const uint8_t hwaddr[static 6], size_t hwaddrlen)
 {
     if (hwaddrlen != 6)
         suicide("%s: Hardware address length=%u != 6 bytes",
@@ -92,7 +92,7 @@ static int open_duidfile_write(void)
     return fd;
 }
 
-static int open_iaidfile_read(uint8_t *hwaddr, size_t hwaddrlen)
+static int open_iaidfile_read(const uint8_t hwaddr[static 6], size_t hwaddrlen)
 {
     char iaidfile[PATH_MAX];
     get_iaid_path(iaidfile, sizeof iaidfile, hwaddr, hwaddrlen);
@@ -104,7 +104,8 @@ static int open_iaidfile_read(uint8_t *hwaddr, size_t hwaddrlen)
     return fd;
 }
 
-static int open_iaidfile_write(uint8_t *hwaddr, size_t hwaddrlen)
+static int open_iaidfile_write(const uint8_t hwaddr[static 6],
+                               size_t hwaddrlen)
 {
     char iaidfile[PATH_MAX];
     get_iaid_path(iaidfile, sizeof iaidfile, hwaddr, hwaddrlen);
@@ -120,8 +121,8 @@ static int open_iaidfile_write(uint8_t *hwaddr, size_t hwaddrlen)
 // RFC6355 specifies a RFC4122 UUID, but I simply use a 128-byte random
 // value, as the complexity of RFC4122 UUID generation is completely
 // unwarranted for DHCPv4.
-static size_t generate_duid(struct nk_random_state_u32 *s, char *dest,
-                            size_t dlen)
+static size_t generate_duid(struct nk_random_state_u32 s[static 1],
+                            char dest[static 1], size_t dlen)
 {
     const size_t tlen = sizeof(uint16_t) + 4 * sizeof(uint32_t);
     if (dlen < tlen)
@@ -142,8 +143,8 @@ static size_t generate_duid(struct nk_random_state_u32 *s, char *dest,
 
 // RFC6355 specifies the IAID as a 32-bit value that uniquely identifies
 // a hardware link for a given host.
-static size_t generate_iaid(struct nk_random_state_u32 *s, char *dest,
-                            size_t dlen)
+static size_t generate_iaid(struct nk_random_state_u32 s[static 1],
+                            char dest[static 1], size_t dlen)
 {
     if (dlen < sizeof(uint32_t))
         suicide("%s: dlen < %u", __func__, sizeof(uint32_t));
@@ -156,7 +157,8 @@ static size_t generate_iaid(struct nk_random_state_u32 *s, char *dest,
 }
 
 // Failures are all fatal.
-void get_clientid(struct client_state_t cs[static 1], struct client_config_t cc[static 1])
+void get_clientid(struct client_state_t cs[static 1],
+                  struct client_config_t cc[static 1])
 {
     if (cc->clientid_len > 0)
         return;
diff --git a/src/duiaid.h b/src/duiaid.h
index ccfc074..4ba5f96 100644
--- a/src/duiaid.h
+++ b/src/duiaid.h
@@ -30,6 +30,7 @@
 
 #include "ndhc.h"
 
-void get_clientid(struct client_state_t cs[static 1], struct client_config_t cc[static 1]);
+void get_clientid(struct client_state_t cs[static 1],
+                  struct client_config_t cc[static 1]);
 
 #endif /* NJK_NDHC_DUIAID_H_ */
diff --git a/src/ifchange.c b/src/ifchange.c
index a5d23bf..abd1390 100644
--- a/src/ifchange.c
+++ b/src/ifchange.c
@@ -47,7 +47,8 @@
 
 static struct dhcpmsg cfg_packet; // Copy of the current configuration packet.
 
-static int ifcmd_raw(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_raw(char buf[static 1], size_t buflen,
+                     const char optname[static 1],
                      char *optdata, ssize_t optlen)
 {
     if (!optdata) {
@@ -77,13 +78,15 @@ static int ifcmd_raw(char buf[static 1], size_t buflen, char *optname,
     return olen;
 }
 
-static int ifcmd_bytes(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_bytes(char buf[static 1], size_t buflen,
+                       const char optname[static 1],
                        uint8_t *optdata, ssize_t optlen)
 {
     return ifcmd_raw(buf, buflen, optname, (char *)optdata, optlen);
 }
 
-static int ifcmd_u8(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_u8(char buf[static 1], size_t buflen,
+                    const char optname[static 1],
                     uint8_t *optdata, ssize_t optlen)
 {
     if (!optdata || optlen < 1)
@@ -96,7 +99,8 @@ static int ifcmd_u8(char buf[static 1], size_t buflen, char *optname,
     return ifcmd_raw(buf, buflen, optname, numbuf, strlen(numbuf));
 }
 
-static int ifcmd_u16(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_u16(char buf[static 1], size_t buflen,
+                     const char optname[static 1],
                      uint8_t *optdata, ssize_t optlen)
 {
     if (!optdata || optlen < 2)
@@ -111,7 +115,8 @@ static int ifcmd_u16(char buf[static 1], size_t buflen, char *optname,
     return ifcmd_raw(buf, buflen, optname, numbuf, strlen(numbuf));
 }
 
-static int ifcmd_s32(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_s32(char buf[static 1], size_t buflen,
+                     const char optname[static 1],
                      uint8_t *optdata, ssize_t optlen)
 {
     if (!optdata || optlen < 4)
@@ -126,7 +131,8 @@ static int ifcmd_s32(char buf[static 1], size_t buflen, char *optname,
     return ifcmd_raw(buf, buflen, optname, numbuf, strlen(numbuf));
 }
 
-static int ifcmd_ip(char buf[static 1], size_t buflen, char *optname,
+static int ifcmd_ip(char buf[static 1], size_t buflen,
+                    const char optname[static 1],
                     uint8_t *optdata, ssize_t optlen)
 {
     if (!optdata || optlen < 4)
@@ -136,7 +142,8 @@ static int ifcmd_ip(char buf[static 1], size_t buflen, char *optname,
     return ifcmd_raw(buf, buflen, optname, ipbuf, strlen(ipbuf));
 }
 
-static int ifcmd_iplist(char *out, size_t outlen, char *optname,
+static int ifcmd_iplist(char out[static 1], size_t outlen,
+                        const char optname[static 1],
                         uint8_t *optdata, ssize_t optlen)
 {
     char buf[2048];
@@ -164,7 +171,8 @@ static int ifcmd_iplist(char *out, size_t outlen, char *optname,
     return ifcmd_raw(out, outlen, optname, buf, strlen(buf));
 }
 
-static int ifchd_cmd(char *b, size_t bl, uint8_t *od, ssize_t ol, uint8_t code)
+static int ifchd_cmd(char b[static 1], size_t bl, uint8_t *od,
+                     ssize_t ol, uint8_t code)
 {
     switch (code) {
     case DCODE_ROUTER: return ifcmd_ip(b, bl, "routr", od, ol);
@@ -184,7 +192,8 @@ static int ifchd_cmd(char *b, size_t bl, uint8_t *od, ssize_t ol, uint8_t code)
     return -1;
 }
 
-static void ifchwrite(struct client_state_t cs[static 1], const char buf[static 1], size_t count)
+static void ifchwrite(struct client_state_t cs[static 1],
+                      const char buf[static 1], size_t count)
 {
     cs->ifchWorking = 1;
     ssize_t r = safe_write(ifchSock[0], buf, count);
@@ -210,7 +219,8 @@ void ifchange_deconfig(struct client_state_t cs[static 1])
     memset(&cfg_packet, 0, sizeof cfg_packet);
 }
 
-static size_t send_client_ip(char *out, size_t olen, struct dhcpmsg *packet)
+static size_t send_client_ip(char out[static 1], size_t olen,
+                             struct dhcpmsg packet[static 1])
 {
     uint8_t optdata[MAX_DOPT_SIZE], olddata[MAX_DOPT_SIZE];
     char ip[INET_ADDRSTRLEN], sn[INET_ADDRSTRLEN], bc[INET_ADDRSTRLEN];
@@ -271,8 +281,8 @@ static size_t send_client_ip(char *out, size_t olen, struct dhcpmsg *packet)
     return snlen;
 }
 
-static size_t send_cmd(char *out, size_t olen, struct dhcpmsg *packet,
-                       uint8_t code)
+static size_t send_cmd(char out[static 1], size_t olen,
+                       struct dhcpmsg packet[static 1], uint8_t code)
 {
     uint8_t optdata[MAX_DOPT_SIZE], olddata[MAX_DOPT_SIZE];
     ssize_t optlen, oldlen;
@@ -290,7 +300,8 @@ static size_t send_cmd(char *out, size_t olen, struct dhcpmsg *packet,
     return r > 0 ? r : 0;
 }
 
-void ifchange_bind(struct client_state_t cs[static 1], struct dhcpmsg *packet)
+void ifchange_bind(struct client_state_t cs[static 1],
+                   struct dhcpmsg packet[static 1])
 {
     char buf[2048];
     size_t bo;
diff --git a/src/ifchange.h b/src/ifchange.h
index c4b2701..f3952b9 100644
--- a/src/ifchange.h
+++ b/src/ifchange.h
@@ -29,7 +29,8 @@
 #ifndef IFCHANGE_H_
 #define IFCHANGE_H_
 
-void ifchange_bind(struct client_state_t cs[static 1], struct dhcpmsg *packet);
+void ifchange_bind(struct client_state_t cs[static 1],
+                   struct dhcpmsg packet[static 1]);
 void ifchange_deconfig(struct client_state_t cs[static 1]);
 
 #endif
diff --git a/src/ifchd-parse.h b/src/ifchd-parse.h
index 58f1626..82d26a6 100644
--- a/src/ifchd-parse.h
+++ b/src/ifchd-parse.h
@@ -29,6 +29,6 @@
 #ifndef _NJK_NDHC_IFCHD_PARSE_H_
 #define _NJK_NDHC_IFCHD_PARSE_H_
 
-int execute_buffer(char *newbuf);
+int execute_buffer(const char newbuf[static 1]);
 
 #endif /* _NJK_NDHC_IFCHD_PARSE_H_ */
diff --git a/src/ifchd-parse.rl b/src/ifchd-parse.rl
index d9b48ae..9c10eb3 100644
--- a/src/ifchd-parse.rl
+++ b/src/ifchd-parse.rl
@@ -180,7 +180,7 @@ static void perform_ip4set(const char buf[static 1], size_t len)
 /*
  * Returns -1 on fatal error; that leads to peer connection being closed.
  */
-int execute_buffer(char *newbuf)
+int execute_buffer(const char newbuf[static 1])
 {
     char buf[MAX_BUF * 2];
     char tb[MAX_BUF];
diff --git a/src/ifchd.c b/src/ifchd.c
index 1608717..0174bce 100644
--- a/src/ifchd.c
+++ b/src/ifchd.c
@@ -172,16 +172,16 @@ static void write_resolve_conf(void)
 }
 
 /* XXX: addme */
-void perform_timezone(const char *str, size_t len)
+void perform_timezone(const char str[static 1], size_t len)
 {
     (void)len;
     log_line("Timezone setting NYI: '%s'", str);
 }
 
 /* Add a dns server to the /etc/resolv.conf -- we already have a fd. */
-void perform_dns(const char *str, size_t len)
+void perform_dns(const char str[static 1], size_t len)
 {
-    if (!str || resolv_conf_fd < 0)
+    if (resolv_conf_fd < 0)
         return;
     if (len > sizeof cl.namesvrs) {
         log_line("DNS server list is too long: %zu > %zu", len, cl.namesvrs);
@@ -197,16 +197,16 @@ void perform_dns(const char *str, size_t len)
 }
 
 /* Updates for print daemons are too non-standard to be useful. */
-void perform_lprsvr(const char *str, size_t len)
+void perform_lprsvr(const char str[static 1], size_t len)
 {
     (void)len;
     log_line("Line printer server setting NYI: '%s'", str);
 }
 
 /* Sets machine hostname. */
-void perform_hostname(const char *str, size_t len)
+void perform_hostname(const char str[static 1], size_t len)
 {
-    if (!allow_hostname || !str)
+    if (!allow_hostname)
         return;
     if (sethostname(str, len) < 0)
         log_line("sethostname returned %s", strerror(errno));
@@ -215,9 +215,9 @@ void perform_hostname(const char *str, size_t len)
 }
 
 /* update "domain" and "search" in /etc/resolv.conf */
-void perform_domain(const char *str, size_t len)
+void perform_domain(const char str[static 1], size_t len)
 {
-    if (!str || resolv_conf_fd < 0)
+    if (resolv_conf_fd < 0)
         return;
     if (len > sizeof cl.domains) {
         log_line("DNS domain list is too long: %zu > %zu", len, cl.namesvrs);
@@ -234,21 +234,21 @@ void perform_domain(const char *str, size_t len)
 
 /* I don't think this can be done without a netfilter extension
  * that isn't in the mainline kernels. */
-void perform_ipttl(const char *str, size_t len)
+void perform_ipttl(const char str[static 1], size_t len)
 {
     (void)len;
     log_line("TTL setting NYI: '%s'", str);
 }
 
 /* XXX: addme */
-void perform_ntpsrv(const char *str, size_t len)
+void perform_ntpsrv(const char str[static 1], size_t len)
 {
     (void)len;
     log_line("NTP server setting NYI: '%s'", str);
 }
 
 /* Maybe Samba cares about this feature?  I don't know. */
-void perform_wins(const char *str, size_t len)
+void perform_wins(const char str[static 1], size_t len)
 {
     (void)str;
     (void)len;
diff --git a/src/ifchd.h b/src/ifchd.h
index b6a545e..5feb0e7 100644
--- a/src/ifchd.h
+++ b/src/ifchd.h
@@ -36,14 +36,14 @@ extern int allow_hostname;
 extern uid_t ifch_uid;
 extern gid_t ifch_gid;
 
-void perform_timezone(const char *str, size_t len);
-void perform_dns(const char *str, size_t len);
-void perform_lprsvr(const char *str, size_t len);
-void perform_hostname(const char *str, size_t len);
-void perform_domain(const char *str, size_t len);
-void perform_ipttl(const char *str, size_t len);
-void perform_ntpsrv(const char *str, size_t len);
-void perform_wins(const char *str, size_t len);
+void perform_timezone(const char str[static 1], size_t len);
+void perform_dns(const char str[static 1], size_t len);
+void perform_lprsvr(const char str[static 1], size_t len);
+void perform_hostname(const char str[static 1], size_t len);
+void perform_domain(const char str[static 1], size_t len);
+void perform_ipttl(const char str[static 1], size_t len);
+void perform_ntpsrv(const char str[static 1], size_t len);
+void perform_wins(const char str[static 1], size_t len);
 
 void ifch_main(void);
 
diff --git a/src/ndhc.c b/src/ndhc.c
index fcbc778..dc342d8 100644
--- a/src/ndhc.c
+++ b/src/ndhc.c
@@ -96,7 +96,7 @@ struct client_config_t client_config = {
     .foreground = 1,
 };
 
-void set_client_addr(const char *v) { cs.clientAddr = inet_addr(v); }
+void set_client_addr(const char v[static 1]) { cs.clientAddr = inet_addr(v); }
 
 void print_version(void)
 {
@@ -212,7 +212,7 @@ static void signal_dispatch(void)
     }
 }
 
-static int is_string_hwaddr(char *str, size_t slen)
+static int is_string_hwaddr(const char str[static 1], size_t slen)
 {
     if (slen == 17 && str[2] == ':' && str[5] == ':' && str[8] == ':' &&
         str[11] == ':' && str[14] == ':' &&
@@ -225,7 +225,7 @@ static int is_string_hwaddr(char *str, size_t slen)
     return 0;
 }
 
-int get_clientid_string(char *str, size_t slen)
+int get_clientid_string(const char str[static 1], size_t slen)
 {
     if (!slen)
         return -1;
diff --git a/src/ndhc.h b/src/ndhc.h
index bb20992..17b95ed 100644
--- a/src/ndhc.h
+++ b/src/ndhc.h
@@ -80,9 +80,9 @@ extern char pidfile[PATH_MAX];
 extern uid_t ndhc_uid;
 extern gid_t ndhc_gid;
 
-void set_client_addr(const char *v);
+void set_client_addr(const char v[static 1]);
 void show_usage(void);
-int get_clientid_string(char *str, size_t slen);
+int get_clientid_string(const char str[static 1], size_t slen);
 void background(void);
 void print_version(void);
 
diff --git a/src/options.c b/src/options.c
index 589e44b..1fbeec3 100644
--- a/src/options.c
+++ b/src/options.c
@@ -34,7 +34,8 @@
 
 #include "options.h"
 
-static int do_overload_value(const uint8_t buf[static 1], ssize_t blen, int overload)
+static int do_overload_value(const uint8_t buf[static 1], ssize_t blen,
+                             int overload)
 {
     ssize_t i = 0;
     while (i < blen) {
@@ -58,7 +59,7 @@ static int do_overload_value(const uint8_t buf[static 1], ssize_t blen, int over
     return overload;
 }
 
-static int overload_value(const struct dhcpmsg *packet)
+static int overload_value(const struct dhcpmsg packet[static 1])
 {
     int ol = do_overload_value(packet->options, sizeof packet->options, 0);
     if (ol & 1 && ol & 2)
@@ -100,8 +101,8 @@ static void do_get_dhcp_opt(const uint8_t *sbuf, ssize_t slen, uint8_t code,
     }
 }
 
-ssize_t get_dhcp_opt(const struct dhcpmsg *packet, uint8_t code, uint8_t *dbuf,
-                     ssize_t dlen)
+ssize_t get_dhcp_opt(const struct dhcpmsg packet[static 1], uint8_t code,
+                     uint8_t *dbuf, ssize_t dlen)
 {
     int ol = overload_value(packet);
     ssize_t didx = 0;
@@ -117,7 +118,7 @@ ssize_t get_dhcp_opt(const struct dhcpmsg *packet, uint8_t code, uint8_t *dbuf,
 }
 
 // return the position of the 'end' option
-ssize_t get_end_option_idx(const struct dhcpmsg *packet)
+ssize_t get_end_option_idx(const struct dhcpmsg packet[static 1])
 {
     for (size_t i = 0; i < sizeof packet->options; ++i) {
         if (packet->options[i] == DCODE_END)
@@ -142,8 +143,8 @@ static inline size_t sizeof_option_str(uint8_t code, size_t datalen)
 // Add a raw data string to the options.  It will take a binary string suitable
 // for use with eg memcpy() and will append it to the options[] field of
 // a dhcp packet with the requested option code and proper length specifier.
-size_t add_option_string(struct dhcpmsg *packet, uint8_t code, const char *str,
-                         size_t slen)
+size_t add_option_string(struct dhcpmsg packet[static 1], uint8_t code,
+                         const char str[static 1], size_t slen)
 {
     size_t len = sizeof_option_str(code, slen);
     if (slen > 255 || len != slen + 2) {
@@ -167,7 +168,7 @@ size_t add_option_string(struct dhcpmsg *packet, uint8_t code, const char *str,
     return len;
 }
 
-static ssize_t add_option_check(struct dhcpmsg *packet, uint8_t code,
+static ssize_t add_option_check(struct dhcpmsg packet[static 1], uint8_t code,
                                 uint8_t rlen)
 {
     ssize_t end = get_end_option_idx(packet);
@@ -183,7 +184,8 @@ static ssize_t add_option_check(struct dhcpmsg *packet, uint8_t code,
     return end;
 }
 
-static size_t add_u8_option(struct dhcpmsg *packet, uint8_t code, uint8_t data)
+static size_t add_u8_option(struct dhcpmsg packet[static 1], uint8_t code,
+                            uint8_t data)
 {
     ssize_t end = add_option_check(packet, code, 1);
     if (end < 0)
@@ -197,7 +199,7 @@ static size_t add_u8_option(struct dhcpmsg *packet, uint8_t code, uint8_t data)
 
 #ifndef NDHS_BUILD
 // Data should be in network byte order.
-static size_t add_u16_option(struct dhcpmsg *packet, uint8_t code,
+static size_t add_u16_option(struct dhcpmsg packet[static 1], uint8_t code,
                              uint16_t data)
 {
     ssize_t end = add_option_check(packet, code, 2);
@@ -214,7 +216,8 @@ static size_t add_u16_option(struct dhcpmsg *packet, uint8_t code,
 #endif
 
 // Data should be in network byte order.
-size_t add_u32_option(struct dhcpmsg *packet, uint8_t code, uint32_t data)
+size_t add_u32_option(struct dhcpmsg packet[static 1], uint8_t code,
+                      uint32_t data)
 {
     ssize_t end = add_option_check(packet, code, 4);
     if (end < 0)
@@ -231,7 +234,7 @@ size_t add_u32_option(struct dhcpmsg *packet, uint8_t code, uint32_t data)
 }
 
 // Add a parameter request list for stubborn DHCP servers
-size_t add_option_request_list(struct dhcpmsg *packet)
+size_t add_option_request_list(struct dhcpmsg packet[static 1])
 {
     static const uint8_t reqdata[] = {
         DCODE_SUBNET, DCODE_ROUTER, DCODE_DNS, DCODE_HOSTNAME, DCODE_DOMAIN,
@@ -242,52 +245,53 @@ size_t add_option_request_list(struct dhcpmsg *packet)
 }
 
 #ifdef NDHS_BUILD
-size_t add_option_domain_name(struct dhcpmsg *packet, const char *dom,
-                              size_t domlen)
+size_t add_option_domain_name(struct dhcpmsg packet[static 1],
+                              const char dom[static 1], size_t domlen)
 {
     return add_option_string(packet, DCODE_DOMAIN, dom, domlen);
 }
 
-void add_option_subnet_mask(struct dhcpmsg *packet, uint32_t subnet)
+void add_option_subnet_mask(struct dhcpmsg packet[static 1], uint32_t subnet)
 {
     add_u32_option(packet, DCODE_SUBNET, subnet);
 }
 
-void add_option_broadcast(struct dhcpmsg *packet, uint32_t bc)
+void add_option_broadcast(struct dhcpmsg packet[static 1], uint32_t bc)
 {
     add_u32_option(packet, DCODE_BROADCAST, bc);
 }
 #endif
 
-void add_option_msgtype(struct dhcpmsg *packet, uint8_t type)
+void add_option_msgtype(struct dhcpmsg packet[static 1], uint8_t type)
 {
     add_u8_option(packet, DCODE_MSGTYPE, type);
 }
 
-void add_option_reqip(struct dhcpmsg *packet, uint32_t ip)
+void add_option_reqip(struct dhcpmsg packet[static 1], uint32_t ip)
 {
     add_u32_option(packet, DCODE_REQIP, ip);
 }
 
-void add_option_serverid(struct dhcpmsg *packet, uint32_t sid)
+void add_option_serverid(struct dhcpmsg packet[static 1], uint32_t sid)
 {
     add_u32_option(packet, DCODE_SERVER_ID, sid);
 }
 
-void add_option_clientid(struct dhcpmsg *packet, const char *clientid,
+void add_option_clientid(struct dhcpmsg packet[static 1],
+                         const char clientid[static 1],
                          size_t clen)
 {
     add_option_string(packet, DCODE_CLIENT_ID, clientid, clen);
 }
 
 #ifndef NDHS_BUILD
-void add_option_maxsize(struct dhcpmsg *packet)
+void add_option_maxsize(struct dhcpmsg packet[static 1])
 {
     add_u16_option(packet, DCODE_MAX_SIZE,
                    htons(sizeof(struct ip_udp_dhcp_packet)));
 }
 
-void add_option_vendor(struct dhcpmsg *packet)
+void add_option_vendor(struct dhcpmsg packet[static 1])
 {
     size_t len = strlen(client_config.vendor);
     if (len)
@@ -296,7 +300,7 @@ void add_option_vendor(struct dhcpmsg *packet)
         add_option_string(packet, DCODE_VENDOR, "ndhc", sizeof "ndhc" - 1);
 }
 
-void add_option_hostname(struct dhcpmsg *packet)
+void add_option_hostname(struct dhcpmsg packet[static 1])
 {
     size_t len = strlen(client_config.hostname);
     if (len)
@@ -304,7 +308,7 @@ void add_option_hostname(struct dhcpmsg *packet)
 }
 #endif
 
-uint32_t get_option_router(const struct dhcpmsg *packet)
+uint32_t get_option_router(const struct dhcpmsg packet[static 1])
 {
     ssize_t ol;
     uint32_t ret = 0;
@@ -315,7 +319,7 @@ uint32_t get_option_router(const struct dhcpmsg *packet)
     return ret;
 }
 
-uint8_t get_option_msgtype(const struct dhcpmsg *packet)
+uint8_t get_option_msgtype(const struct dhcpmsg packet[static 1])
 {
     ssize_t ol;
     uint8_t ret = 0;
@@ -326,7 +330,7 @@ uint8_t get_option_msgtype(const struct dhcpmsg *packet)
     return ret;
 }
 
-uint32_t get_option_serverid(const struct dhcpmsg *packet, int *found)
+uint32_t get_option_serverid(const struct dhcpmsg packet[static 1], int *found)
 {
     ssize_t ol;
     uint32_t ret = 0;
@@ -340,7 +344,7 @@ uint32_t get_option_serverid(const struct dhcpmsg *packet, int *found)
     return ret;
 }
 
-uint32_t get_option_leasetime(const struct dhcpmsg *packet)
+uint32_t get_option_leasetime(const struct dhcpmsg packet[static 1])
 {
     ssize_t ol;
     uint32_t ret = 0;
@@ -354,8 +358,8 @@ uint32_t get_option_leasetime(const struct dhcpmsg *packet)
 }
 
 // Returned buffer is not nul-terminated.
-size_t get_option_clientid(const struct dhcpmsg *packet, const char *cbuf,
-                           size_t clen)
+size_t get_option_clientid(const struct dhcpmsg packet[static 1],
+                           char cbuf[static 1], size_t clen)
 {
     if (clen < 1)
         return 0;
diff --git a/src/options.h b/src/options.h
index c13e28b..57b293b 100644
--- a/src/options.h
+++ b/src/options.h
@@ -56,36 +56,37 @@
 
 #define MAX_DOPT_SIZE 500
 
-ssize_t get_dhcp_opt(const struct dhcpmsg *packet, uint8_t code, uint8_t *dbuf,
-                     ssize_t dlen);
-ssize_t get_end_option_idx(const struct dhcpmsg *packet);
+ssize_t get_dhcp_opt(const struct dhcpmsg packet[static 1], uint8_t code,
+                     uint8_t *dbuf, ssize_t dlen);
+ssize_t get_end_option_idx(const struct dhcpmsg packet[static 1]);
 
-size_t add_option_string(struct dhcpmsg *packet, uint8_t code, const char *str,
-                         size_t slen);
-size_t add_u32_option(struct dhcpmsg *packet, uint8_t code, uint32_t data);
+size_t add_option_string(struct dhcpmsg packet[static 1], uint8_t code,
+                         const char str[static 1], size_t slen);
+size_t add_u32_option(struct dhcpmsg packet[static 1], uint8_t code,
+                      uint32_t data);
 
-size_t add_option_request_list(struct dhcpmsg *packet);
+size_t add_option_request_list(struct dhcpmsg packet[static 1]);
 #ifdef NDHS_BUILD
-size_t add_option_domain_name(struct dhcpmsg *packet, const char *dom,
-                              size_t domlen);
-void add_option_subnet_mask(struct dhcpmsg *packet, uint32_t subnet);
-void add_option_broadcast(struct dhcpmsg *packet, uint32_t bc);
+size_t add_option_domain_name(struct dhcpmsg packet[static 1],
+                              const char dom[static 1], size_t domlen);
+void add_option_subnet_mask(struct dhcpmsg packet[static 1], uint32_t subnet);
+void add_option_broadcast(struct dhcpmsg packet[static 1], uint32_t bc);
 #endif
-void add_option_msgtype(struct dhcpmsg *packet, uint8_t type);
-void add_option_reqip(struct dhcpmsg *packet, uint32_t ip);
-void add_option_serverid(struct dhcpmsg *packet, uint32_t sid);
-void add_option_clientid(struct dhcpmsg *packet, const char *clientid,
-                         size_t clen);
+void add_option_msgtype(struct dhcpmsg packet[static 1], uint8_t type);
+void add_option_reqip(struct dhcpmsg packet[static 1], uint32_t ip);
+void add_option_serverid(struct dhcpmsg packet[static 1], uint32_t sid);
+void add_option_clientid(struct dhcpmsg packet[static 1],
+                         const char clientid[static 1], size_t clen);
 #ifndef NDHS_BUILD
-void add_option_maxsize(struct dhcpmsg *packet);
-void add_option_vendor(struct dhcpmsg *packet);
-void add_option_hostname(struct dhcpmsg *packet);
+void add_option_maxsize(struct dhcpmsg packet[static 1]);
+void add_option_vendor(struct dhcpmsg packet[static 1]);
+void add_option_hostname(struct dhcpmsg packet[static 1]);
 #endif
-uint32_t get_option_router(const struct dhcpmsg *packet);
-uint8_t get_option_msgtype(const struct dhcpmsg *packet);
-uint32_t get_option_serverid(const struct dhcpmsg *packet, int *found);
-uint32_t get_option_leasetime(const struct dhcpmsg *packet);
-size_t get_option_clientid(const struct dhcpmsg *packet, const char *cbuf,
-                           size_t clen);
+uint32_t get_option_router(const struct dhcpmsg packet[static 1]);
+uint8_t get_option_msgtype(const struct dhcpmsg packet[static 1]);
+uint32_t get_option_serverid(const struct dhcpmsg packet[static 1], int *found);
+uint32_t get_option_leasetime(const struct dhcpmsg packet[static 1]);
+size_t get_option_clientid(const struct dhcpmsg packet[static 1],
+                           char cbuf[static 1], size_t clen);
 
 #endif
diff --git a/src/state.c b/src/state.c
index a0055e0..ae64552 100644
--- a/src/state.c
+++ b/src/state.c
@@ -41,9 +41,9 @@
 #include "ndhc.h"
 #include "sys.h"
 
-static void selecting_packet(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+static void selecting_packet(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                              uint8_t msgtype, uint32_t srcaddr);
-static void an_packet(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+static void an_packet(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                       uint8_t msgtype, uint32_t srcaddr);
 static void selecting_timeout(struct client_state_t cs[static 1], long long nowts);
 static void requesting_timeout(struct client_state_t cs[static 1], long long nowts);
@@ -56,7 +56,7 @@ static void print_release(struct client_state_t cs[static 1]);
 static void frenew(struct client_state_t cs[static 1]);
 
 typedef struct {
-    void (*packet_fn)(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+    void (*packet_fn)(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                       uint8_t msgtype, uint32_t srcaddr);
     void (*timeout_fn)(struct client_state_t cs[static 1], long long nowts);
     void (*force_renew_fn)(struct client_state_t cs[static 1]);
@@ -201,7 +201,7 @@ static void released_timeout(struct client_state_t cs[static 1], long long nowts
     dhcp_wake_ts = -1;
 }
 
-static int validate_serverid(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+static int validate_serverid(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                              char *typemsg)
 {
     int found;
@@ -223,7 +223,7 @@ static int validate_serverid(struct client_state_t cs[static 1], struct dhcpmsg
 }
 
 // Can transition to DS_BOUND or DS_SELECTING.
-static void an_packet(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+static void an_packet(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                       uint8_t msgtype, uint32_t srcaddr)
 {
     (void)srcaddr;
@@ -280,7 +280,7 @@ static void an_packet(struct client_state_t cs[static 1], struct dhcpmsg *packet
     }
 }
 
-static void selecting_packet(struct client_state_t cs[static 1], struct dhcpmsg *packet,
+static void selecting_packet(struct client_state_t cs[static 1], struct dhcpmsg packet[static 1],
                              uint8_t msgtype, uint32_t srcaddr)
 {
     if (msgtype == DHCPOFFER) {
@@ -405,8 +405,9 @@ void ifnocarrier_action(struct client_state_t cs[static 1])
     log_line("%s: Carrier down.", client_config.interface);
 }
 
-void packet_action(struct client_state_t cs[static 1], struct dhcpmsg *packet,
-                   uint8_t msgtype, uint32_t srcaddr)
+void packet_action(struct client_state_t cs[static 1],
+                   struct dhcpmsg packet[static 1], uint8_t msgtype,
+                   uint32_t srcaddr)
 {
     if (dhcp_states[cs->dhcpState].packet_fn)
         dhcp_states[cs->dhcpState].packet_fn(cs, packet, msgtype, srcaddr);
diff --git a/src/state.h b/src/state.h
index aab52b2..b196a0e 100644
--- a/src/state.h
+++ b/src/state.h
@@ -45,8 +45,9 @@ typedef enum {
 
 void reinit_selecting(struct client_state_t cs[static 1], int timeout);
 
-void packet_action(struct client_state_t cs[static 1], struct dhcpmsg *packet,
-                   uint8_t msgtype, uint32_t srcaddr);
+void packet_action(struct client_state_t cs[static 1],
+                   struct dhcpmsg packet[static 1], uint8_t msgtype,
+                   uint32_t srcaddr);
 void timeout_action(struct client_state_t cs[static 1], long long nowts);
 void force_renew_action(struct client_state_t cs[static 1]);
 void force_release_action(struct client_state_t cs[static 1]);
diff --git a/src/sys.c b/src/sys.c
index c9d74e1..3d6ab9d 100644
--- a/src/sys.c
+++ b/src/sys.c
@@ -75,7 +75,7 @@ int setup_signals_subprocess(void)
     return sfd;
 }
 
-void signal_dispatch_subprocess(int sfd, const char *pname)
+void signal_dispatch_subprocess(int sfd, const char pname[static 1])
 {
     struct signalfd_siginfo si = {0};
     ssize_t r = safe_read(sfd, (char *)&si, sizeof si);
diff --git a/src/sys.h b/src/sys.h
index b88cdbc..598bc8a 100644
--- a/src/sys.h
+++ b/src/sys.h
@@ -47,7 +47,7 @@ void epoll_add(int epfd, int fd);
 void epoll_del(int epfd, int fd);
 
 int setup_signals_subprocess(void);
-void signal_dispatch_subprocess(int sfd, const char *pname);
+void signal_dispatch_subprocess(int sfd, const char pname[static 1]);
 
 #endif /* SYS_H_ */