zcip: convert lots of zero-initialized locals

      in zcip_main() to statics in bss.

1 files changed, 43 insertions, 41 deletions

diff --git a/networking/zcip.c b/networking/zcip.c
index 176bc0101..e781a5882 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -72,11 +72,6 @@ enum {
         DEFEND
 };
 
-/* Implicitly zero-initialized */
-static const struct in_addr null_ip;
-static const struct ether_addr null_addr;
-static int verbose;
-
 #define DBG(fmt,args...) \
         do { } while (0)
 #define VDBG    DBG
@@ -188,28 +183,35 @@ static unsigned ATTRIBUTE_ALWAYS_INLINE ms_rdelay(unsigned secs)
  * main program
  */
 
+/* Used to be auto variables on main() stack, but
+ * most of them were zero-inited. Moving them to bss
+ * is more space-efficient.
+ */
+static  const struct in_addr null_ip; // = { 0 };
+static  const struct ether_addr null_addr; // = { {0, 0, 0, 0, 0, 0} };
+
+static  struct sockaddr saddr; // memset(0);
+static  struct in_addr ip; // = { 0 };
+static  struct ifreq ifr; //memset(0);
+
+static  char *intf; // = NULL;
+static  char *script; // = NULL;
+static  suseconds_t timeout; // = 0;    // milliseconds
+static  unsigned conflicts; // = 0;
+static  unsigned nprobes; // = 0;
+static  unsigned nclaims; // = 0;
+static  int ready; // = 0;
+static  int quit; // = 0;
+static  int foreground; // = 0;
+static  int verbose; // = 0;
+static  int state = PROBE;
+
 int zcip_main(int argc, char *argv[])
 {
-        char *intf = NULL;
-        char *script = NULL;
-        int quit = 0;
-        int foreground = 0;
-
+        struct ether_addr eth_addr;
         char *why;
-        struct sockaddr saddr;
-        struct ether_addr addr;
-        struct in_addr ip = { 0 };
         int fd;
-        int ready = 0;
-        suseconds_t timeout = 0;        // milliseconds
-        unsigned conflicts = 0;
-        unsigned nprobes = 0;
-        unsigned nclaims = 0;
         int t;
-        int state = PROBE;
-
-        struct ifreq ifr;
-        unsigned short seed[3];
 
         // parse commandline: prog [options] ifname script
         while ((t = getopt(argc, argv, "fqr:v")) != EOF) {
@@ -249,7 +251,7 @@ int zcip_main(int argc, char *argv[])
                 return EXIT_FAILURE;
 
         // initialize saddr
-        memset(&saddr, 0, sizeof (saddr));
+        //memset(&saddr, 0, sizeof (saddr));
         safe_strncpy(saddr.sa_data, intf, sizeof (saddr.sa_data));
 
         // open an ARP socket
@@ -258,21 +260,21 @@ int zcip_main(int argc, char *argv[])
         xbind(fd, &saddr, sizeof (saddr);
 
         // get the interface's ethernet address
-        memset(&ifr, 0, sizeof (ifr));
+        //memset(&ifr, 0, sizeof (ifr));
         strncpy(ifr.ifr_name, intf, sizeof (ifr.ifr_name));
         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
                 foreground = 1;
                 why = "get ethernet address";
                 goto bad;
         }
-        memcpy(&addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
+        memcpy(&eth_addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 
         // start with some stable ip address, either a function of
         // the hardware address or else the last address we used.
         // NOTE: the sequence of addresses we try changes only
         // depending on when we detect conflicts.
-        memcpy(seed, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
-        seed48(seed);
+        // (SVID 3 bogon: who says that "short" is always 16 bits?)
+        seed48( (unsigned short*)&ifr.ifr_hwaddr.sa_data );
         if (ip.s_addr == 0)
                 pick(&ip);
 
@@ -299,13 +301,13 @@ int zcip_main(int argc, char *argv[])
                 struct timeval tv1;
                 struct arp_packet p;
 
+                int source_ip_conflict = 0;
+                int target_ip_conflict = 0;
+
                 fds[0].fd = fd;
                 fds[0].events = POLLIN;
                 fds[0].revents = 0;
 
-                int source_ip_conflict = 0;
-                int target_ip_conflict = 0;
-
                 // poll, being ready to adjust current timeout
                 if (!timeout) {
                         timeout = ms_rdelay(PROBE_WAIT);
@@ -338,7 +340,7 @@ int zcip_main(int argc, char *argv[])
                                         VDBG("probe/%d %s@%s\n",
                                                         nprobes, intf, inet_ntoa(ip));
                                         (void)arp(fd, &saddr, ARPOP_REQUEST,
-                                                        &addr, null_ip,
+                                                        &eth_addr, null_ip,
                                                         &null_addr, ip);
                                         timeout = PROBE_MIN * 1000;
                                         timeout += ms_rdelay(PROBE_MAX
@@ -351,8 +353,8 @@ int zcip_main(int argc, char *argv[])
                                         VDBG("announce/%d %s@%s\n",
                                                         nclaims, intf, inet_ntoa(ip));
                                         (void)arp(fd, &saddr, ARPOP_REQUEST,
-                                                        &addr, ip,
-                                                        &addr, ip);
+                                                        &eth_addr, ip,
+                                                        &eth_addr, ip);
                                         timeout = ANNOUNCE_INTERVAL * 1000;
                                 }
                                 break;
@@ -364,8 +366,8 @@ int zcip_main(int argc, char *argv[])
                                 VDBG("announce/%d %s@%s\n",
                                                 nclaims, intf, inet_ntoa(ip));
                                 (void)arp(fd, &saddr, ARPOP_REQUEST,
-                                                &addr, ip,
-                                                &addr, ip);
+                                                &eth_addr, ip,
+                                                &eth_addr, ip);
                                 timeout = ANNOUNCE_INTERVAL * 1000;
                                 break;
                         case ANNOUNCE:
@@ -376,8 +378,8 @@ int zcip_main(int argc, char *argv[])
                                         VDBG("announce/%d %s@%s\n",
                                                         nclaims, intf, inet_ntoa(ip));
                                         (void)arp(fd, &saddr, ARPOP_REQUEST,
-                                                        &addr, ip,
-                                                        &addr, ip);
+                                                        &eth_addr, ip,
+                                                        &eth_addr, ip);
                                         timeout = ANNOUNCE_INTERVAL * 1000;
                                 }
                                 else {
@@ -477,12 +479,12 @@ int zcip_main(int argc, char *argv[])
                                 continue;
 
                         if (memcmp(p.arp.arp_spa, &ip.s_addr, sizeof(struct in_addr)) == 0 &&
-                                memcmp(&addr, &p.arp.arp_sha, ETH_ALEN) != 0) {
+                                memcmp(&eth_addr, &p.arp.arp_sha, ETH_ALEN) != 0) {
                                 source_ip_conflict = 1;
                         }
                         if (memcmp(p.arp.arp_tpa, &ip.s_addr, sizeof(struct in_addr)) == 0 &&
                                 p.arp.arp_op == htons(ARPOP_REQUEST) &&
-                                memcmp(&addr, &p.arp.arp_tha, ETH_ALEN) != 0) {
+                                memcmp(&eth_addr, &p.arp.arp_tha, ETH_ALEN) != 0) {
                                 target_ip_conflict = 1;
                         }
 
@@ -516,8 +518,8 @@ int zcip_main(int argc, char *argv[])
                                         timeout = DEFEND_INTERVAL * 1000;
                                         (void)arp(fd, &saddr,
                                                         ARPOP_REQUEST,
-                                                        &addr, ip,
-                                                        &addr, ip);
+                                                        &eth_addr, ip,
+                                                        &eth_addr, ip);
                                 }
                                 break;
                         case DEFEND: