464xlat: rework process id write logic

[feed/routing.git] / nat46 / src / 464xlatcfg.c

diff --git a/nat46/src/464xlatcfg.c b/nat46/src/464xlatcfg.c
index 1d9466ed98681bcdb4cdc6d5f07eeb157ff273ba..0f9ad318126e39a7121e24a71c94b3779433e2a6 100644 (file)
--- a/nat46/src/464xlatcfg.c
+++ b/nat46/src/464xlatcfg.c
@@ -1,6 +1,7 @@
 /* 464xlatcfg.c
  *
  * Copyright (c) 2015 Steven Barth <cyrus@openwrt.org>
+ * Copyright (c) 2017 Hans Dedecker <dedeckeh@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2
@@ -40,8 +41,9 @@ int main(int argc, const char *argv[])
        snprintf(buf, sizeof(buf), "/var/run/%s.pid", argv[1]);
        FILE *fp = fopen(buf, "r");
        if (fp) {
-               fscanf(fp, "%d", &pid);
-               kill(pid, SIGTERM);
+               if (fscanf(fp, "%d", &pid) == 1)
+                       kill(pid, SIGTERM);
+
                unlink(buf);
                fclose(fp);
        }
@@ -52,7 +54,9 @@ int main(int argc, const char *argv[])
        if (!argv[3] || !argv[4] || !(fp = fopen(buf, "wx")))
                return 1;
 
-       signal(SIGTERM, sighandler);
+       signal(SIGTERM, SIG_DFL);
+       setvbuf(fp, NULL, _IOLBF, 0);
+       fprintf(fp, "%d\n", getpid());
 
        prefix[sizeof(prefix) - 1] = 0;
        strncpy(prefix, argv[3], sizeof(prefix) - 1);
@@ -71,19 +75,39 @@ int main(int argc, const char *argv[])
                freeaddrinfo(res);
        }
                
-       struct sockaddr_in6 saddr = {.sin6_family = AF_INET6, .sin6_addr = {{{0x20, 0x01, 0x0d, 0xb8}}}};
-       socklen_t saddrlen = sizeof(saddr);
-       int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
-       struct icmp6_filter filt;
-       ICMP6_FILTER_SETBLOCKALL(&filt);
-       setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
-       setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, argv[2], strlen(argv[2]));
-       if (connect(sock, (struct sockaddr*)&saddr, sizeof(saddr)) ||
-                       getsockname(sock, (struct sockaddr*)&saddr, &saddrlen))
-               return 3;
+       int i = 0;
+       int sock;
+       struct sockaddr_in6 saddr;
+
+       do {
+               socklen_t saddrlen = sizeof(saddr);
+               struct icmp6_filter filt;
+
+               sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
+               ICMP6_FILTER_SETBLOCKALL(&filt);
+               setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
+               setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, argv[2], strlen(argv[2]));
+               memset(&saddr, 0, sizeof(saddr));
+               saddr.sin6_family = AF_INET6;
+               saddr.sin6_addr.s6_addr32[0] = htonl(0x2001);
+               saddr.sin6_addr.s6_addr32[1] = htonl(0xdb8);
+               if (connect(sock, (struct sockaddr*)&saddr, sizeof(saddr)) ||
+                               getsockname(sock, (struct sockaddr*)&saddr, &saddrlen))
+                       return 3;
+
+               if (!IN6_IS_ADDR_LINKLOCAL(&saddr.sin6_addr) || argv[5])
+                       break;
+
+               close(sock);
+               sleep(3);
+               i++;
+       } while (i < 3);
        
        struct ipv6_mreq mreq = {saddr.sin6_addr, if_nametoindex(argv[2])};
        if (!argv[5]) {
+               if (IN6_IS_ADDR_LINKLOCAL(&mreq.ipv6mr_multiaddr))
+                       return 5;
+
                srandom(mreq.ipv6mr_multiaddr.s6_addr32[0] ^ mreq.ipv6mr_multiaddr.s6_addr32[1] ^
                                mreq.ipv6mr_multiaddr.s6_addr32[2] ^ mreq.ipv6mr_multiaddr.s6_addr32[3]);
                mreq.ipv6mr_multiaddr.s6_addr32[2] = random();
@@ -113,6 +137,7 @@ int main(int argc, const char *argv[])
                fclose(stderr);
                chdir("/");
                setsid();
+               signal(SIGTERM, sighandler);
                pause();
 
                nat46 = fopen("/proc/net/nat46/control", "w");
@@ -121,6 +146,7 @@ int main(int argc, const char *argv[])
                        fclose(nat46);
                }
        } else {
+               rewind(fp);
                fprintf(fp, "%d\n", pid);
        }