ftp: code shrink
[oweals/busybox.git] / networking / traceroute.c
index 577738a97959d59c1dd624e56e985ad588d3c456..7284f0022d51facd417c4cd71db3ed07d2b603f8 100644 (file)
@@ -22,9 +22,6 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-//#define version "1.4a12"
-
-
 /*
  * traceroute host  - trace the route ip packets follow going to "host".
  *
 #include "libbb.h"
 #include "inet_common.h"
 
-
-/*
- * Definitions for internet protocol version 4.
- * Per RFC 791, September 1981.
- */
-#define IPVERSION 4
-
 #ifndef IPPROTO_ICMP
-/* Grrrr.... */
-#define IPPROTO_ICMP 1
+# define IPPROTO_ICMP 1
 #endif
 #ifndef IPPROTO_IP
-#define IPPROTO_IP 0
+# define IPPROTO_IP 0
 #endif
 
-/*
- * Overlay for ip header used by other protocols (tcp, udp).
- */
-struct ipovly {
-       unsigned char  ih_x1[9];               /* (unused) */
-       unsigned char  ih_pr;                  /* protocol */
-       short   ih_len;                 /* protocol length */
-       struct  in_addr ih_src;         /* source internet address */
-       struct  in_addr ih_dst;         /* destination internet address */
+/* Keep in sync with getopt32 call! */
+enum {
+       OPT_DONT_FRAGMNT = (1 << 0),    /* F */
+       OPT_USE_ICMP     = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
+       OPT_TTL_FLAG     = (1 << 2),    /* l */
+       OPT_ADDR_NUM     = (1 << 3),    /* n */
+       OPT_BYPASS_ROUTE = (1 << 4),    /* r */
+       OPT_DEBUG        = (1 << 5),    /* d */
+       OPT_VERBOSE      = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
+       OPT_IP_CHKSUM    = (1 << 7),    /* x */
+       OPT_TOS          = (1 << 8),    /* t */
+       OPT_DEVICE       = (1 << 9),    /* i */
+       OPT_MAX_TTL      = (1 << 10),   /* m */
+       OPT_PORT         = (1 << 11),   /* p */
+       OPT_NPROBES      = (1 << 12),   /* q */
+       OPT_SOURCE       = (1 << 13),   /* s */
+       OPT_WAITTIME     = (1 << 14),   /* w */
+       OPT_PAUSE_MS     = (1 << 15),   /* z */
+       OPT_FIRST_TTL    = (1 << 16),   /* f */
 };
+#define verbose (option_mask32 & OPT_VERBOSE)
 
-/*
- * UDP kernel structures and variables.
- */
-struct udpiphdr {
-       struct  ipovly ui_i;            /* overlaid ip structure */
-       struct  udphdr ui_u;            /* udp header */
-};
-#define ui_next         ui_i.ih_next
-#define ui_prev         ui_i.ih_prev
-#define ui_x1           ui_i.ih_x1
-#define ui_pr           ui_i.ih_pr
-#define ui_len          ui_i.ih_len
-#define ui_src          ui_i.ih_src
-#define ui_dst          ui_i.ih_dst
-#define ui_sport        ui_u.uh_sport
-#define ui_dport        ui_u.uh_dport
-#define ui_ulen         ui_u.uh_ulen
-#define ui_sum          ui_u.uh_sum
-
-
-/* Host name and address list */
-struct hostinfo {
-       char *name;
-       int n;
-       uint32_t *addrs;
+enum {
+       SIZEOF_ICMP_HDR = 8,
+       rcvsock = 3, /* receive (icmp) socket file descriptor */
+       sndsock = 4, /* send (udp/icmp) socket file descriptor */
 };
 
 /* Data section of the probe packet */
-struct outdata {
+struct outdata_t {
        unsigned char seq;             /* sequence number of this packet */
        unsigned char ttl;             /* ttl packet left with */
 // UNUSED. Retaining to have the same packet size.
-       struct timeval tv_UNUSED ATTRIBUTE_PACKED; /* time packet left */
-};
-
-struct IFADDRLIST {
-       uint32_t addr;
-       char device[sizeof(struct ifreq)];
+       struct timeval tv_UNUSED PACKED; /* time packet left */
 };
 
-
-static struct ip *outip;               /* last output (udp) packet */
-static struct udphdr *outudp;          /* last output (udp) packet */
-static struct outdata *outdata;        /* last output (udp) packet */
-
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-static struct icmp *outicmp;           /* last output (icmp) packet */
-#endif
-
-static int s;                          /* receive (icmp) socket file descriptor */
-static int sndsock;                    /* send (udp/icmp) socket file descriptor */
-
-static int packlen;                    /* total length of packet */
-static int minpacket;                  /* min ip packet size */
-static int maxpacket = 32 * 1024;      /* max ip packet size */
-static int pmtu;                       /* Path MTU Discovery (RFC1191) */
-
-static char *hostname;
-
-static uint16_t ident;
-static uint16_t port = 32768 + 666;     /* start udp dest port # for probe packets */
-
-static int waittime = 5;               /* time to wait for response (in seconds) */
-static int doipcksum = 1;              /* calculate ip checksums by default */
-
+struct globals {
+       struct ip *outip;
+       struct outdata_t *outdata;
+       len_and_sockaddr *dest_lsa;
+       int packlen;                    /* total length of packet */
+       int pmtu;                       /* Path MTU Discovery (RFC1191) */
+       uint16_t ident;
+       uint16_t port; // 32768 + 666;  /* start udp dest port # for probe packets */
+       int waittime; // 5;             /* time to wait for response (in seconds) */
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
-static int optlen;                     /* length of ip options */
+       int optlen;                     /* length of ip options */
 #else
 #define optlen 0
 #endif
-
-
-/* Keep in sync with getopt32 call! */
-#define OPT_DONT_FRAGMNT (1<<0)    /* F */
-#define OPT_USE_ICMP     (1<<1)    /* I */
-#define OPT_TTL_FLAG     (1<<2)    /* l */
-#define OPT_ADDR_NUM     (1<<3)    /* n */
-#define OPT_BYPASS_ROUTE (1<<4)    /* r */
-#define OPT_DEBUG        (1<<5)    /* d */
-#define OPT_VERBOSE      (1<<6)    /* v */
-#define OPT_IP_CHKSUM    (1<<7)    /* x */
-#define OPT_TOS          (1<<8)    /* t */
-#define OPT_DEVICE       (1<<9)    /* i */
-#define OPT_MAX_TTL      (1<<10)   /* m */
-#define OPT_PORT         (1<<11)   /* p */
-#define OPT_NPROBES      (1<<12)   /* q */
-#define OPT_SOURCE       (1<<13)   /* s */
-#define OPT_WAITTIME     (1<<14)   /* w */
-#define OPT_PAUSE_MS     (1<<15)   /* z */
-#define OPT_FIRST_TTL    (1<<16)   /* f */
-
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-/* use icmp echo instead of udp packets */
-#define useicmp (option_mask32 & OPT_USE_ICMP)
-#endif
-#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
-#define verbose (option_mask32 & OPT_VERBOSE)
-#endif
-#define nflag   (option_mask32 & OPT_ADDR_NUM)
-
-
-struct globals {
-       /* last inbound (icmp) packet */
-       unsigned char packet[512];
-       struct sockaddr_storage whereto;        /* Who to try to reach */
-       struct sockaddr_storage wherefrom;      /* Who we are */
+       unsigned char recv_pkt[512];    /* last inbound (icmp) packet */
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
        /* Maximum number of gateways (include room for one noop) */
 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
@@ -359,199 +282,41 @@ struct globals {
 };
 
 #define G (*ptr_to_globals)
-
-#define packet    (G.packet   )
-#define whereto   (G.whereto  )
-#define wherefrom (G.wherefrom)
-#define gwlist    (G.gwlist   )
-
-
-/*
- * Return the interface list
- */
-static int
-ifaddrlist(struct IFADDRLIST **ipaddrp)
-{
-       enum { IFREQ_BUFSIZE = (32 * 1024) / sizeof(struct ifreq) };
-
-       int fd, nipaddr;
-#ifdef HAVE_SOCKADDR_SA_LEN
-       int n;
-#endif
-       struct ifreq *ifrp, *ifend, *ifnext;
-       struct sockaddr_in *addr_sin;
-       struct IFADDRLIST *al;
-       struct ifconf ifc;
-       struct ifreq ifr;
-       /* Was on stack, but 32k is a bit too much: */
-       struct ifreq *ibuf = xmalloc(IFREQ_BUFSIZE * sizeof(ibuf[0]));
-       struct IFADDRLIST *st_ifaddrlist;
-
-       fd = xsocket(AF_INET, SOCK_DGRAM, 0);
-
-       ifc.ifc_len = IFREQ_BUFSIZE * sizeof(ibuf[0]);
-       ifc.ifc_buf = (caddr_t)ibuf;
-
-       if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
-        || ifc.ifc_len < sizeof(struct ifreq)
-       ) {
-               if (errno == EINVAL)
-                       bb_error_msg_and_die(
-                           "SIOCGIFCONF: ifreq struct too small (%d bytes)",
-                           IFREQ_BUFSIZE * sizeof(ibuf[0]));
-               bb_perror_msg_and_die("SIOCGIFCONF");
-       }
-       ifrp = ibuf;
-       ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
-
-       nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
-       st_ifaddrlist = xzalloc(nipaddr * sizeof(struct IFADDRLIST));
-       al = st_ifaddrlist;
-       nipaddr = 0;
-
-       for (; ifrp < ifend; ifrp = ifnext) {
-#ifdef HAVE_SOCKADDR_SA_LEN
-               n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
-               if (n < sizeof(*ifrp))
-                       ifnext = ifrp + 1;
-               else
-                       ifnext = (struct ifreq *)((char *)ifrp + n);
-               if (ifrp->ifr_addr.sa_family != AF_INET)
-                       continue;
-#else
-               ifnext = ifrp + 1;
-#endif
-               /*
-                * Need a template to preserve address info that is
-                * used below to locate the next entry.  (Otherwise,
-                * SIOCGIFFLAGS stomps over it because the requests
-                * are returned in a union.)
-                */
-               strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
-               if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
-                       if (errno == ENXIO)
-                               continue;
-                       bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
-                           (int)sizeof(ifr.ifr_name), ifr.ifr_name);
-               }
-
-               /* Must be up */
-               if ((ifr.ifr_flags & IFF_UP) == 0)
-                       continue;
-
-               safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
-#ifdef sun
-               /* Ignore sun virtual interfaces */
-               if (strchr(al->device, ':') != NULL)
-                       continue;
-#endif
-               if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
-                       bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
-
-               addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
-               al->addr = addr_sin->sin_addr.s_addr;
-               ++al;
-               ++nipaddr;
-       }
-       if (nipaddr == 0)
-               bb_error_msg_and_die("can't find any network interfaces");
-
-       free(ibuf);
-       close(fd);
-       *ipaddrp = st_ifaddrlist;
-       return nipaddr;
-}
-
-
-static void
-setsin(struct sockaddr_in *addr_sin, uint32_t addr)
-{
-       memset(addr_sin, 0, sizeof(*addr_sin));
-#ifdef HAVE_SOCKADDR_SA_LEN
-       addr_sin->sin_len = sizeof(*addr_sin);
+#define outip     (G.outip    )
+#define outdata   (G.outdata  )
+#define dest_lsa  (G.dest_lsa )
+#define packlen   (G.packlen  )
+#define pmtu      (G.pmtu     )
+#define ident     (G.ident    )
+#define port      (G.port     )
+#define waittime  (G.waittime )
+#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
+# define optlen   (G.optlen   )
 #endif
-       addr_sin->sin_family = AF_INET;
-       addr_sin->sin_addr.s_addr = addr;
-}
-
-
-/*
- * Return the source address for the given destination address
- */
-static void
-findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
-{
-       int i, n;
-       FILE *f;
-       uint32_t mask;
-       uint32_t dest, tmask;
-       struct IFADDRLIST *al;
-       char buf[256], tdevice[256], device[256];
-
-       f = xfopen("/proc/net/route", "r");
-
-       /* Find the appropriate interface */
-       n = 0;
-       mask = 0;
-       device[0] = '\0';
-       while (fgets(buf, sizeof(buf), f) != NULL) {
-               ++n;
-               if (n == 1 && strncmp(buf, "Iface", 5) == 0)
-                       continue;
-               i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
-                                       tdevice, &dest, &tmask);
-               if (i != 3)
-                       bb_error_msg_and_die("junk in buffer");
-               if ((to->sin_addr.s_addr & tmask) == dest
-                && (tmask > mask || mask == 0)
-               ) {
-                       mask = tmask;
-                       strcpy(device, tdevice);
-               }
-       }
-       fclose(f);
-
-       if (device[0] == '\0')
-               bb_error_msg_and_die("can't find interface");
-
-       /* Get the interface address list */
-       n = ifaddrlist(&al);
-
-       /* Find our appropriate source address */
-       for (i = n; i > 0; --i, ++al)
-               if (strcmp(device, al->device) == 0)
-                       break;
-       if (i <= 0)
-               bb_error_msg_and_die("can't find interface %s", device);
-
-       setsin(from, al->addr);
-}
+#define recv_pkt  (G.recv_pkt )
+#define gwlist    (G.gwlist   )
+#define INIT_G() do { \
+       SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+       port = 32768 + 666; \
+       waittime = 5; \
+} while (0)
 
-/*
-"Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
-"\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
-"\t[-w waittime] [-z pausemsecs] host [packetlen]"
+#define outicmp ((struct icmp *)(outip + 1))
+#define outudp  ((struct udphdr *)(outip + 1))
 
-*/
 
 static int
-wait_for_reply(int sock, struct sockaddr_in *fromp)
+wait_for_reply(struct sockaddr_in *fromp)
 {
-       fd_set fds;
-       struct timeval tvwait;
+       struct pollfd pfd[1];
        int cc = 0;
        socklen_t fromlen = sizeof(*fromp);
 
-       FD_ZERO(&fds);
-       FD_SET(sock, &fds);
-
-       tvwait.tv_sec = waittime;
-       tvwait.tv_usec = 0;
-
-       if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
-               cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
+       pfd[0].fd = rcvsock;
+       pfd[0].events = POLLIN;
+       if (safe_poll(pfd, 1, waittime * 1000) > 0)
+               cc = recvfrom(rcvsock, recv_pkt, sizeof(recv_pkt), 0,
                            (struct sockaddr *)fromp, &fromlen);
-
        return cc;
 }
 
@@ -567,12 +332,12 @@ in_cksum(uint16_t *addr, int len)
        int sum = 0;
 
        /*
-        *  Our algorithm is simple, using a 32 bit accumulator (sum),
-        *  we add sequential 16 bit words to it, and at the end, fold
-        *  back all the carry bits from the top 16 bits into the lower
-        *  16 bits.
+        * Our algorithm is simple, using a 32 bit accumulator (sum),
+        * we add sequential 16 bit words to it, and at the end, fold
+        * back all the carry bits from the top 16 bits into the lower
+        * 16 bits.
         */
-       while (nleft > 1)  {
+       while (nleft > 1) {
                sum += *w++;
                nleft -= 2;
        }
@@ -581,37 +346,18 @@ in_cksum(uint16_t *addr, int len)
        if (nleft == 1)
                sum += *(unsigned char *)w;
 
-       /*
-        * add back carry outs from top 16 bits to low 16 bits
-        */
+       /* add back carry outs from top 16 bits to low 16 bits */
        sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
        sum += (sum >> 16);                     /* add carry */
        answer = ~sum;                          /* truncate to 16 bits */
        return answer;
 }
 
-
 static void
 send_probe(int seq, int ttl)
 {
-       int cc;
-       struct udpiphdr *ui, *oui;
-       struct ip tip;
-
-       outip->ip_ttl = ttl;
-       outip->ip_id = htons(ident + seq);
-
-       /*
-        * In most cases, the kernel will recalculate the ip checksum.
-        * But we must do it anyway so that the udp checksum comes out
-        * right.
-        */
-       if (doipcksum) {
-               outip->ip_sum =
-                   in_cksum((uint16_t *)outip, sizeof(*outip) + optlen);
-               if (outip->ip_sum == 0)
-                       outip->ip_sum = 0xffff;
-       }
+       int len, res;
+       void *out;
 
        /* Payload */
        outdata->seq = seq;
@@ -619,42 +365,19 @@ send_probe(int seq, int ttl)
 // UNUSED: was storing gettimeofday's result there, but never ever checked it
        /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
 
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-       if (useicmp)
+       if (option_mask32 & OPT_USE_ICMP) {
                outicmp->icmp_seq = htons(seq);
-       else
-#endif
-               outudp->dest = htons(port + seq);
 
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-       if (useicmp) {
                /* Always calculate checksum for icmp packets */
                outicmp->icmp_cksum = 0;
                outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
-                   packlen - (sizeof(*outip) + optlen));
+                                       packlen - (sizeof(*outip) + optlen));
                if (outicmp->icmp_cksum == 0)
                        outicmp->icmp_cksum = 0xffff;
-       } else
-#endif
-       if (doipcksum) {
-               /* Checksum (we must save and restore ip header) */
-               tip = *outip;
-               ui = (struct udpiphdr *)outip;
-               oui = (struct udpiphdr *)&tip;
-               /* Easier to zero and put back things that are ok */
-               memset((char *)ui, 0, sizeof(ui->ui_i));
-               ui->ui_src = oui->ui_src;
-               ui->ui_dst = oui->ui_dst;
-               ui->ui_pr = oui->ui_pr;
-               ui->ui_len = outudp->len;
-               outudp->check = 0;
-               outudp->check = in_cksum((uint16_t *)ui, packlen);
-               if (outudp->check == 0)
-                       outudp->check = 0xffff;
-               *outip = tip;
        }
 
-#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
+//BUG! verbose is (x & OPT_VERBOSE), not a counter!
+#if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
        /* XXX undocumented debugging hack */
        if (verbose > 1) {
                const uint16_t *sp;
@@ -679,17 +402,25 @@ send_probe(int seq, int ttl)
        }
 #endif
 
-#if !defined(IP_HDRINCL) && defined(IP_TTL)
+#if defined(IP_TTL)
        if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
-           (char *)&ttl, sizeof(ttl)) < 0) {
+                               (char *)&ttl, sizeof(ttl)) < 0) {
                bb_perror_msg_and_die("setsockopt ttl %d", ttl);
        }
 #endif
 
-       cc = xsendto(sndsock, (char *)outip,
-           packlen, (struct sockaddr *)&whereto, sizeof(whereto));
-       if (cc != packlen)  {
-               bb_info_msg("wrote %s %d chars, ret=%d", hostname, packlen, cc);
+       len = packlen - sizeof(*outip);
+       if (option_mask32 & OPT_USE_ICMP)
+               out = outicmp;
+       else {
+               out = outdata;
+               len -= sizeof(*outudp);
+               set_nport(dest_lsa, htons(port + seq));
+       }
+       res = xsendto(sndsock, out, len,
+                       (struct sockaddr *)&dest_lsa->u.sa, dest_lsa->len);
+       if (res != len) {
+               bb_info_msg("sent %d octets, ret=%d", len, res);
        }
 }
 
@@ -700,7 +431,7 @@ send_probe(int seq, int ttl)
 static inline const char *
 pr_type(unsigned char t)
 {
-       static const char * const ttab[] = {
+       static const char *const ttab[] = {
        "Echo Reply",   "ICMP 1",       "ICMP 2",       "Dest Unreachable",
        "Source Quench", "Redirect",    "ICMP 6",       "ICMP 7",
        "Echo",         "Router Advert", "Router Solicit", "Time Exceeded",
@@ -708,22 +439,26 @@ pr_type(unsigned char t)
        "Info Reply",   "Mask Request", "Mask Reply"
        };
 
-       if (t > 18)
+       if (t >= ARRAY_SIZE(ttab))
                return "OUT-OF-RANGE";
 
        return ttab[t];
 }
 #endif
 
+#if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
+#define packet_ok(cc, from, seq) \
+       packet_ok(cc, seq)
+#endif
 static int
-packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
+packet_ok(int cc, const struct sockaddr_in *from, int seq)
 {
-       struct icmp *icp;
+       const struct icmp *icp;
        unsigned char type, code;
        int hlen;
-       struct ip *ip;
+       const struct ip *ip;
 
-       ip = (struct ip *) buf;
+       ip = (struct ip *) recv_pkt;
        hlen = ip->ip_hl << 2;
        if (cc < hlen + ICMP_MINLEN) {
 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
@@ -734,49 +469,54 @@ packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
                return 0;
        }
        cc -= hlen;
-       icp = (struct icmp *)(buf + hlen);
+       icp = (struct icmp *)(recv_pkt + hlen);
        type = icp->icmp_type;
        code = icp->icmp_code;
        /* Path MTU Discovery (RFC1191) */
-       if (code != ICMP_UNREACH_NEEDFRAG)
-               pmtu = 0;
-       else {
+       pmtu = 0;
+       if (code == ICMP_UNREACH_NEEDFRAG)
                pmtu = ntohs(icp->icmp_nextmtu);
-       }
-       if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
-           type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
-               struct ip *hip;
-               struct udphdr *up;
+
+       if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
+        || type == ICMP_UNREACH
+        || type == ICMP_ECHOREPLY
+       ) {
+               const struct ip *hip;
+               const struct udphdr *up;
 
                hip = &icp->icmp_ip;
                hlen = hip->ip_hl << 2;
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-               if (useicmp) {
+               if (option_mask32 & OPT_USE_ICMP) {
                        struct icmp *hicmp;
 
                        /* XXX */
-                       if (type == ICMP_ECHOREPLY &&
-                           icp->icmp_id == htons(ident) &&
-                           icp->icmp_seq == htons(seq))
+                       if (type == ICMP_ECHOREPLY
+                        && icp->icmp_id == htons(ident)
+                        && icp->icmp_seq == htons(seq)
+                       ) {
                                return -2;
+                       }
 
                        hicmp = (struct icmp *)((unsigned char *)hip + hlen);
-                       /* XXX 8 is a magic number */
-                       if (hlen + 8 <= cc &&
-                           hip->ip_p == IPPROTO_ICMP &&
-                           hicmp->icmp_id == htons(ident) &&
-                           hicmp->icmp_seq == htons(seq))
+                       if (hlen + SIZEOF_ICMP_HDR <= cc
+                        && hip->ip_p == IPPROTO_ICMP
+                        && hicmp->icmp_id == htons(ident)
+                        && hicmp->icmp_seq == htons(seq)
+                       ) {
                                return (type == ICMP_TIMXCEED ? -1 : code + 1);
-               } else
-#endif
-               {
-                       up = (struct udphdr *)((unsigned char *)hip + hlen);
-                       /* XXX 8 is a magic number */
-                       if (hlen + 12 <= cc &&
-                           hip->ip_p == IPPROTO_UDP &&
-                           up->source == htons(ident) &&
-                           up->dest == htons(port + seq))
+                       }
+               } else {
+                       up = (struct udphdr *)((char *)hip + hlen);
+                       if (hlen + 12 <= cc
+                        && hip->ip_p == IPPROTO_UDP
+// Off: since we do not form the entire IP packet,
+// but defer it to kernel, we can't set source port,
+// and thus can't check it here in the reply
+                       /* && up->source == htons(ident) */
+                        && up->dest == htons(port + seq)
+                       ) {
                                return (type == ICMP_TIMXCEED ? -1 : code + 1);
+                       }
                }
        }
 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
@@ -786,8 +526,9 @@ packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
 
                printf("\n%d bytes from %s to "
                       "%s: icmp type %d (%s) code %d\n",
-                   cc, inet_ntoa(from->sin_addr),
-                   inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
+                       cc, inet_ntoa(from->sin_addr),
+                       inet_ntoa(ip->ip_dst),
+                       type, pr_type(type), icp->icmp_code);
                for (i = 4; i < cc; i += sizeof(*lp))
                        printf("%2d: x%8.8x\n", i, *lp++);
        }
@@ -795,153 +536,91 @@ packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
        return 0;
 }
 
-
 /*
  * Construct an Internet address representation.
- * If the nflag has been supplied, give
+ * If the -n flag has been supplied, give
  * numeric value, otherwise try for symbolic name.
  */
-static inline void
-print_inetname(struct sockaddr_in *from)
+static void
+print_inetname(const struct sockaddr_in *from)
 {
        const char *ina;
 
        ina = inet_ntoa(from->sin_addr);
-       if (nflag)
-               printf(" %s", ina);
+       if (option_mask32 & OPT_ADDR_NUM)
+               printf("  %s", ina);
        else {
                char *n = NULL;
                if (from->sin_addr.s_addr != INADDR_ANY)
-                       n = xmalloc_sockaddr2host_noport((struct sockaddr*)from, sizeof(*from));
-               printf(" %s (%s)", (n ? n : ina), ina);
+                       n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
+               printf("  %s (%s)", (n ? n : ina), ina);
                free(n);
        }
 }
 
-static inline void
-print(unsigned char *buf, int cc, struct sockaddr_in *from)
+static void
+print(int cc, const struct sockaddr_in *from)
 {
-       struct ip *ip;
-       int hlen;
-
-       ip = (struct ip *) buf;
-       hlen = ip->ip_hl << 2;
-       cc -= hlen;
-
        print_inetname(from);
-#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
-       if (verbose)
-               printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
-#endif
-}
-
+       if (verbose) {
+               const struct ip *ip;
+               int hlen;
 
-static struct hostinfo *
-gethostinfo(const char *host)
-{
-       int n;
-       struct hostent *hp;
-       struct hostinfo *hi;
-       char **p;
-       uint32_t addr, *ap;
-
-       hi = xzalloc(sizeof(*hi));
-       addr = inet_addr(host);
-       if (addr != 0xffffffff) {
-               hi->name = xstrdup(host);
-               hi->n = 1;
-               hi->addrs = xzalloc(sizeof(hi->addrs[0]));
-               hi->addrs[0] = addr;
-               return hi;
+               ip = (struct ip *) recv_pkt;
+               hlen = ip->ip_hl << 2;
+               cc -= hlen;
+               printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
        }
-
-       hp = xgethostbyname(host);
-       if (hp->h_addrtype != AF_INET || hp->h_length != 4)
-               bb_perror_msg_and_die("bad host %s", host);
-       hi->name = xstrdup(hp->h_name);
-       for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
-               continue;
-       hi->n = n;
-       hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
-       for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
-               memcpy(ap, *p, sizeof(*ap));
-       return hi;
-}
-
-static void
-freehostinfo(struct hostinfo *hi)
-{
-       free(hi->name);
-       free(hi->addrs);
-       free(hi);
-}
-
-#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
-static void
-getaddr(uint32_t *ap, const char *host)
-{
-       struct hostinfo *hi;
-
-       hi = gethostinfo(host);
-       *ap = hi->addrs[0];
-       freehostinfo(hi);
 }
-#endif
 
 static void
 print_delta_ms(unsigned t1p, unsigned t2p)
 {
        unsigned tt = t2p - t1p;
-       printf("  %u.%03u ms", tt/1000, tt%1000);
+       printf("  %u.%03u ms", tt / 1000, tt % 1000);
 }
 
-int traceroute_main(int argc, char **argv);
+/*
+Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
+[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
+[-w waittime] [-z pausemsecs] host [packetlen]"
+*/
+
+int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int traceroute_main(int argc, char **argv)
 {
-       int code, n;
-       unsigned char *outp;
-       uint32_t *ap;
-       struct sockaddr_in *from;
-       struct sockaddr_in *to;
-       struct hostinfo *hi;
-       int ttl, probe, i;
+       int minpacket;
+       int ttl, i;
        int seq = 0;
        int tos = 0;
-       char *tos_str;
-       char *source;
+       int max_ttl = 30;
+       int nprobes = 3;
+       int first_ttl = 1;
+       unsigned pausemsecs = 0;
        unsigned op;
-#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
-       int lsrr = 0;
-#endif
-       uint16_t off = 0;
-       struct IFADDRLIST *al;
+       char *source;
        char *device;
-       int max_ttl = 30;
+       char *tos_str;
        char *max_ttl_str;
        char *port_str;
-       int nprobes = 3;
        char *nprobes_str;
        char *waittime_str;
-       unsigned pausemsecs = 0;
        char *pausemsecs_str;
-       int first_ttl = 1;
        char *first_ttl_str;
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
        llist_t *source_route_list = NULL;
+       int lsrr = 0;
 #endif
 
-       PTR_TO_GLOBALS = xzalloc(sizeof(G));
-       from = (struct sockaddr_in *)&wherefrom;
-       to = (struct sockaddr_in *)&whereto;
+       INIT_G();
 
-       //opterr = 0;
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
        opt_complementary = "x-x:g::";
 #else
        opt_complementary = "x-x";
 #endif
 
-       op = getopt32(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
+       op = getopt32(argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
                                        "g:"
 #endif
@@ -952,12 +631,10 @@ int traceroute_main(int argc, char **argv)
 #endif
        );
 
-       if (op & OPT_DONT_FRAGMNT)
-               off = IP_DF;
-       if (op & OPT_IP_CHKSUM) {
-               doipcksum = 0;
+#if 0 /* IGNORED */
+       if (op & OPT_IP_CHKSUM)
                bb_error_msg("warning: ip checksums disabled");
-       }
+#endif
        if (op & OPT_TOS)
                tos = xatou_range(tos_str, 0, 255);
        if (op & OPT_MAX_TTL)
@@ -971,69 +648,47 @@ int traceroute_main(int argc, char **argv)
                 * set the ip source address of the outbound
                 * probe (e.g., on a multi-homed host).
                 */
-               if (getuid())
-                       bb_error_msg_and_die("-s %s: permission denied", source);
+               if (getuid() != 0)
+                       bb_error_msg_and_die("you must be root to use -s");
        }
        if (op & OPT_WAITTIME)
-               waittime = xatou_range(waittime_str, 2, 24 * 60 * 60);
+               waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
        if (op & OPT_PAUSE_MS)
                pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
        if (op & OPT_FIRST_TTL)
-               first_ttl = xatou_range(first_ttl_str, 1, 255);
+               first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
 
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
        if (source_route_list) {
-               llist_t *l_sr;
+               while (source_route_list) {
+                       len_and_sockaddr *lsa;
 
-               l_sr = source_route_list;
-               while (l_sr) {
                        if (lsrr >= NGATEWAYS)
                                bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
-                       getaddr(gwlist + lsrr, l_sr->data);
+                       lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
+                       gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
+                       free(lsa);
                        ++lsrr;
-                       l_sr = l_sr->link;
-                       free(source_route_list);
-                       source_route_list = l_sr;
                }
                optlen = (lsrr + 1) * sizeof(gwlist[0]);
        }
 #endif
 
-       if (first_ttl > max_ttl) {
-               bb_error_msg_and_die(
-                   "first ttl (%d) may not be greater than max ttl (%d)",
-                   first_ttl, max_ttl);
-       }
-
-       minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
-
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-       if (useicmp)
-               minpacket += 8;                 /* XXX magic number */
-       else
-#endif
-               minpacket += sizeof(*outudp);
-       packlen = minpacket;                    /* minimum sized packet */
+       minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
+       if (!(op & OPT_USE_ICMP))
+               minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
+       packlen = minpacket;
 
        /* Process destination and optional packet size */
-       switch (argc - optind) {
-
+       argv += optind;
+       argc -= optind;
+       switch (argc) {
        case 2:
-               packlen = xatoul_range(argv[optind + 1], minpacket, maxpacket);
+               packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
                /* Fall through */
-
        case 1:
-               hostname = argv[optind];
-               hi = gethostinfo(hostname);
-               setsin(to, hi->addrs[0]);
-               if (hi->n > 1)
-                       bb_error_msg("warning: %s has multiple addresses; using %s",
-                               hostname, inet_ntoa(to->sin_addr));
-               hostname = hi->name;
-               hi->name = NULL;
-               freehostinfo(hi);
+               dest_lsa = xhost2sockaddr(argv[0], port);
                break;
-
        default:
                bb_show_usage();
        }
@@ -1041,26 +696,27 @@ int traceroute_main(int argc, char **argv)
        /* Ensure the socket fds won't be 0, 1 or 2 */
        bb_sanitize_stdio();
 
-       s = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
-
+       xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
 #if TRACEROUTE_SO_DEBUG
        if (op & OPT_DEBUG)
-               setsockopt(s, SOL_SOCKET, SO_DEBUG,
+               setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
                                &const_int_1, sizeof(const_int_1));
 #endif
        if (op & OPT_BYPASS_ROUTE)
-               setsockopt(s, SOL_SOCKET, SO_DONTROUTE,
+               setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
                                &const_int_1, sizeof(const_int_1));
 
-       sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
-
+       if (op & OPT_USE_ICMP)
+               xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
+       else
+               xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
 #if defined(IP_OPTIONS)
        if (lsrr > 0) {
                unsigned char optlist[MAX_IPOPTLEN];
 
                /* final hop */
-               gwlist[lsrr] = to->sin_addr.s_addr;
+               gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
                ++lsrr;
 
                /* force 4 byte alignment */
@@ -1069,35 +725,31 @@ int traceroute_main(int argc, char **argv)
                optlist[1] = IPOPT_LSRR;
                i = lsrr * sizeof(gwlist[0]);
                optlist[2] = i + 3;
-               /* Pointer to LSRR addresses */
+               /* pointer to LSRR addresses */
                optlist[3] = IPOPT_MINOFF;
                memcpy(optlist + 4, gwlist, i);
 
-               if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
-                   (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
+               if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
+                               (char *)optlist, i + sizeof(gwlist[0])) < 0) {
                        bb_perror_msg_and_die("IP_OPTIONS");
                }
        }
 #endif /* IP_OPTIONS */
 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
-
 #ifdef SO_SNDBUF
        if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
                bb_perror_msg_and_die("SO_SNDBUF");
        }
 #endif
-#ifdef IP_HDRINCL
-       if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, &const_int_1, sizeof(const_int_1)) < 0
-        && errno != ENOPROTOOPT
-       ) {
-               bb_perror_msg_and_die("IP_HDRINCL");
-       }
-#else
 #ifdef IP_TOS
-       if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
+       if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
                bb_perror_msg_and_die("setsockopt tos %d", tos);
        }
 #endif
+#ifdef IP_DONTFRAG
+       if (op & OPT_DONT_FRAGMNT)
+               setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
+                               &const_int_1, sizeof(const_int_1));
 #endif
 #if TRACEROUTE_SO_DEBUG
        if (op & OPT_DEBUG)
@@ -1108,230 +760,167 @@ int traceroute_main(int argc, char **argv)
                setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
                                &const_int_1, sizeof(const_int_1));
 
-       /* Revert to non-privileged user after opening sockets */
-       xsetgid(getgid());
-       xsetuid(getuid());
-
        outip = xzalloc(packlen);
 
-       outip->ip_v = IPVERSION;
-       if (tos_str)
-               outip->ip_tos = tos;
-       outip->ip_len = htons(packlen);
-       outip->ip_off = htons(off);
-       outp = (unsigned char *)(outip + 1);
-       outip->ip_dst = to->sin_addr;
-
-       outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
-       ident = (getpid() & 0xffff) | 0x8000;
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-       if (useicmp) {
-               outip->ip_p = IPPROTO_ICMP;
-               outicmp = (struct icmp *)outp;
+       if (op & OPT_USE_ICMP) {
+               ident = getpid() | 0x8000;
                outicmp->icmp_type = ICMP_ECHO;
                outicmp->icmp_id = htons(ident);
-               outdata = (struct outdata *)(outp + 8); /* XXX magic number */
-       } else
-#endif
-       {
-               outip->ip_p = IPPROTO_UDP;
-               outudp = (struct udphdr *)outp;
-               outudp->source = htons(ident);
-               outudp->len = htons((uint16_t)(packlen - (sizeof(*outip) + optlen)));
-               outdata = (struct outdata *)(outudp + 1);
+               outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
+       } else {
+               outdata = (struct outdata_t *)(outudp + 1);
        }
 
-       /* Get the interface address list */
-       n = ifaddrlist(&al);
-
-       /* Look for a specific device */
-       if (op & OPT_DEVICE) {
-               for (i = n; i > 0; --i, ++al)
-                       if (strcmp(device, al->device) == 0)
-                               goto found_dev;
-               bb_error_msg_and_die("can't find interface %s", device);
-       }
- found_dev:
+       if (op & OPT_DEVICE) /* hmm, do we need error check? */
+               setsockopt_bindtodevice(sndsock, device);
 
-       /* Determine our source address */
-       if (!(op & OPT_SOURCE)) {
-               /*
-                * If a device was specified, use the interface address.
-                * Otherwise, try to determine our source address.
-                */
-               if (op & OPT_DEVICE)
-                       setsin(from, al->addr);
-               findsaddr(to, from);
-       } else {
-               hi = gethostinfo(source);
-               source = hi->name;
-               hi->name = NULL;
-               /*
-                * If the device was specified make sure it
-                * corresponds to the source address specified.
-                * Otherwise, use the first address (and warn if
-                * there are more than one).
-                */
-               if (op & OPT_DEVICE) {
-                       for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
-                               if (*ap == al->addr)
-                                       goto found_dev2;
-                       bb_error_msg_and_die("%s is not on interface %s",
-                                       source, device);
- found_dev2:
-                       setsin(from, *ap);
-               } else {
-                       setsin(from, hi->addrs[0]);
-                       if (hi->n > 1)
-                               bb_error_msg(
-                       "warning: %s has multiple addresses; using %s",
-                                   source, inet_ntoa(from->sin_addr));
-               }
-               freehostinfo(hi);
+       if (op & OPT_SOURCE) {
+               len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
+               /* Ping does this (why?) */
+               if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
+                               &source_lsa->u.sa, source_lsa->len))
+                       bb_error_msg_and_die("can't set multicast source interface");
+//TODO: we can query source port we bound to,
+// and check it in replies... if we care enough
+               xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
+               free(source_lsa);
        }
 
-       outip->ip_src = from->sin_addr;
-#ifndef IP_HDRINCL
-       xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
-#endif
+       /* Revert to non-privileged user after opening sockets */
+       xsetgid(getgid());
+       xsetuid(getuid());
 
-       printf("traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
+       printf("traceroute to %s (%s)", argv[0],
+                       xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
        if (op & OPT_SOURCE)
                printf(" from %s", source);
        printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
-       fflush(stdout);
 
        for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
+//TODO: make it protocol agnostic (get rid of sockaddr_in)
+               struct sockaddr_in from;
                uint32_t lastaddr = 0;
-               int gotlastaddr = 0;
+               int probe;
+               int unreachable = 0; /* counter */
+               int gotlastaddr = 0; /* flags */
                int got_there = 0;
-               int unreachable = 0;
-               int sentfirst = 0;
+               int first = 1;
 
-               printf("%2d ", ttl);
+               printf("%2d", ttl);
                for (probe = 0; probe < nprobes; ++probe) {
                        int cc;
                        unsigned t1;
                        unsigned t2;
                        struct ip *ip;
 
-                       if (sentfirst && pausemsecs > 0)
+                       if (!first && pausemsecs > 0)
                                usleep(pausemsecs * 1000);
+                       fflush(stdout);
+
                        t1 = monotonic_us();
                        send_probe(++seq, ttl);
-                       ++sentfirst;
-                       while ((cc = wait_for_reply(s, from)) != 0) {
+                       first = 0;
+
+                       while ((cc = wait_for_reply(&from)) != 0) {
                                t2 = monotonic_us();
-                               i = packet_ok(packet, cc, from, seq);
+                               i = packet_ok(cc, &from, seq);
                                /* Skip short packet */
                                if (i == 0)
                                        continue;
-                               if (!gotlastaddr ||
-                                   from->sin_addr.s_addr != lastaddr) {
-                                       print(packet, cc, from);
-                                       lastaddr = from->sin_addr.s_addr;
-                                       ++gotlastaddr;
+                               if (!gotlastaddr
+                                || from.sin_addr.s_addr != lastaddr
+                               ) {
+                                       print(cc, &from);
+                                       lastaddr = from.sin_addr.s_addr;
+                                       gotlastaddr = 1;
                                }
                                print_delta_ms(t1, t2);
-                               ip = (struct ip *)packet;
+                               ip = (struct ip *)recv_pkt;
                                if (op & OPT_TTL_FLAG)
                                        printf(" (%d)", ip->ip_ttl);
                                if (i == -2) {
                                        if (ip->ip_ttl <= 1)
                                                printf(" !");
-                                       ++got_there;
+                                       got_there = 1;
                                        break;
                                }
                                /* time exceeded in transit */
                                if (i == -1)
                                        break;
-                               code = i - 1;
-                               switch (code) {
-
+                               i--;
+                               switch (i) {
                                case ICMP_UNREACH_PORT:
                                        if (ip->ip_ttl <= 1)
                                                printf(" !");
-                                       ++got_there;
+                                       got_there = 1;
                                        break;
-
                                case ICMP_UNREACH_NET:
-                                       ++unreachable;
                                        printf(" !N");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_HOST:
-                                       ++unreachable;
                                        printf(" !H");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_PROTOCOL:
-                                       ++got_there;
                                        printf(" !P");
+                                       got_there = 1;
                                        break;
-
                                case ICMP_UNREACH_NEEDFRAG:
-                                       ++unreachable;
                                        printf(" !F-%d", pmtu);
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_SRCFAIL:
-                                       ++unreachable;
                                        printf(" !S");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_FILTER_PROHIB:
                                case ICMP_UNREACH_NET_PROHIB:   /* misuse */
-                                       ++unreachable;
                                        printf(" !A");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_HOST_PROHIB:
-                                       ++unreachable;
                                        printf(" !C");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_HOST_PRECEDENCE:
-                                       ++unreachable;
                                        printf(" !V");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_PRECEDENCE_CUTOFF:
-                                       ++unreachable;
                                        printf(" !C");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_NET_UNKNOWN:
                                case ICMP_UNREACH_HOST_UNKNOWN:
-                                       ++unreachable;
                                        printf(" !U");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_ISOLATED:
-                                       ++unreachable;
                                        printf(" !I");
+                                       ++unreachable;
                                        break;
-
                                case ICMP_UNREACH_TOSNET:
                                case ICMP_UNREACH_TOSHOST:
-                                       ++unreachable;
                                        printf(" !T");
+                                       ++unreachable;
                                        break;
-
                                default:
+                                       printf(" !<%d>", i);
                                        ++unreachable;
-                                       printf(" !<%d>", code);
                                        break;
                                }
                                break;
                        }
                        if (cc == 0)
-                               printf(" *");
-                       (void)fflush(stdout);
+                               printf("  *");
                }
-               putchar('\n');
-               if (got_there ||
-                   (unreachable > 0 && unreachable >= nprobes - 1))
+               bb_putchar('\n');
+               if (got_there
+                || (unreachable > 0 && unreachable >= nprobes - 1)
+               ) {
                        break;
+               }
        }
        return 0;
 }