zcip: convert lots of zero-initialized locals

      in zcip_main() to statics in bss.

diff --git a/networking/zcip.c b/networking/zcip.c
index 176bc01..e781a58 100644 (file)
--- 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: