1 files changed, 166 insertions, 559 deletions

diff --git a/networking/traceroute.c b/networking/traceroute.c
index 958299aaa..244a74d6d 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -215,13 +215,6 @@
 #include "libbb.h"
 #include "inet_common.h"
 
-
-/*
- * Definitions for internet protocol version 4.
- * Per RFC 791, September 1981.
- */
-#define IPVERSION 4
-
 #ifndef IPPROTO_ICMP
 # define IPPROTO_ICMP 1
 #endif
@@ -229,122 +222,57 @@
 # 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 */
-typedef 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 PACKED; /* time packet left */
-} outdata_t;
-
-struct IFADDRLIST {
-        uint32_t addr;
-        char device[sizeof(struct ifreq)];
 };
 
-
-/* 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 {
-        struct ip *outip;               /* last output (udp) packet */
-        struct udphdr *outudp;          /* last output (udp) packet */
-        struct outdata *outdata;        /* last output (udp) packet */
-
-#if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
-        struct icmp *outicmp;           /* last output (icmp) packet */
-#endif
-
-        int rcvsock;                    /* receive (icmp) socket file descriptor */
-        int sndsock;                    /* send (udp/icmp) socket file descriptor */
-
+        struct ip *outip;
+        struct outdata_t *outdata;
+        len_and_sockaddr *dest_lsa;
         int packlen;                    /* total length of packet */
-        int minpacket;                  /* min ip packet size */
-        int maxpacket; // 32 * 1024;    /* max ip packet size */
         int pmtu;                       /* Path MTU Discovery (RFC1191) */
-
-        char *hostname;
-
         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) */
-        int doipcksum; // 1;            /* calculate ip checksums by default */
-
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
         int optlen;                     /* length of ip options */
 #else
 #define optlen 0
 #endif
-
-        struct sockaddr_storage whereto;        /* Who to try to reach */
-        struct sockaddr_storage wherefrom;      /* Who we are */
-        /* last inbound (icmp) packet */
-        unsigned char packet[512];
+        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)))
@@ -355,206 +283,39 @@ struct globals {
 
 #define G (*ptr_to_globals)
 #define outip     (G.outip    )
-#define outudp    (G.outudp   )
 #define outdata   (G.outdata  )
-#define outicmp   (G.outicmp  )
-#define rcvsock   (G.rcvsock  )
-#define sndsock   (G.sndsock  )
+#define dest_lsa  (G.dest_lsa )
 #define packlen   (G.packlen  )
-#define minpacket (G.minpacket)
-#define maxpacket (G.maxpacket)
 #define pmtu      (G.pmtu     )
-#define hostname  (G.hostname )
 #define ident     (G.ident    )
 #define port      (G.port     )
 #define waittime  (G.waittime )
-#define doipcksum (G.doipcksum)
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
-#define optlen    (G.optlen   )
+# define optlen   (G.optlen   )
 #endif
-#define packet    (G.packet   )
-#define whereto   (G.whereto  )
-#define wherefrom (G.wherefrom)
+#define recv_pkt  (G.recv_pkt )
 #define gwlist    (G.gwlist   )
 #define INIT_G() do { \
         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
-        maxpacket = 32 * 1024; \
         port = 32768 + 666; \
         waittime = 5; \
-        doipcksum = 1; \
 } while (0)
 
+#define outicmp ((struct icmp *)(outip + 1))
+#define outudp  ((struct udphdr *)(outip + 1))
 
-/*
- * 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 < (int)sizeof(struct ifreq)
-        ) {
-                if (errno == EINVAL)
-                        bb_error_msg_and_die(
-                            "SIOCGIFCONF: ifreq struct too small (%u bytes)",
-                            (unsigned)(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_IFNAMSIZ(ifr.ifr_name, ifrp->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
-                ioctl_or_perror_and_die(fd, SIOCGIFADDR, (char *)&ifr,
-                                "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);
-#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_for_read("/proc/net/route");
-
-        /* 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);
-}
 
 static int
-wait_for_reply(int sock, struct sockaddr_in *fromp)
+wait_for_reply(struct sockaddr_in *fromp)
 {
         struct pollfd pfd[1];
         int cc = 0;
         socklen_t fromlen = sizeof(*fromp);
 
-        pfd[0].fd = sock;
+        pfd[0].fd = rcvsock;
         pfd[0].events = POLLIN;
         if (safe_poll(pfd, 1, waittime * 1000) > 0)
-                cc = recvfrom(sock, packet, sizeof(packet), 0,
+                cc = recvfrom(rcvsock, recv_pkt, sizeof(recv_pkt), 0,
                             (struct sockaddr *)fromp, &fromlen);
         return cc;
 }
@@ -595,22 +356,8 @@ in_cksum(uint16_t *addr, int len)
 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;
@@ -618,39 +365,15 @@ 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));
                 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(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;
         }
 
 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
@@ -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) {
                 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
         }
 #endif
 
-        cc = xsendto(sndsock, outip, packlen,
-                        (struct sockaddr *)&whereto, sizeof(whereto));
-        if (cc != packlen) {
-                bb_info_msg("sent %s %d octets, 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);
         }
 }
 
@@ -716,18 +447,18 @@ pr_type(unsigned char t)
 #endif
 
 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
-#define packet_ok(buf, cc, from, seq) \
-        packet_ok(buf, cc, seq)
+#define packet_ok(cc, from, seq) \
+        packet_ok(cc, seq)
 #endif
 static int
-packet_ok(const unsigned char *buf, int cc, const struct sockaddr_in *from, int seq)
+packet_ok(int cc, const struct sockaddr_in *from, int seq)
 {
         const struct icmp *icp;
         unsigned char type, code;
         int hlen;
         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
@@ -738,7 +469,7 @@ packet_ok(const unsigned char *buf, int cc, const struct sockaddr_in *from, int
                 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) */
@@ -755,33 +486,37 @@ packet_ok(const unsigned char *buf, int cc, const struct sockaddr_in *from, int
 
                 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
@@ -812,85 +547,31 @@ 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);
-                printf(" %s (%s)", (n ? n : ina), ina);
+                printf("  %s (%s)", (n ? n : ina), ina);
                 free(n);
         }
 }
 
 static void
-print(const unsigned char *buf, int cc, const struct sockaddr_in *from)
+print(int cc, const struct sockaddr_in *from)
 {
-        const 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)
@@ -900,46 +581,38 @@ print_delta_ms(unsigned t1p, unsigned t2p)
 }
 
 /*
-"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]"
+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)
 {
-        unsigned char *outp;
-        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
-        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
 
         INIT_G();
-        from = (struct sockaddr_in *)&wherefrom;
-        to = (struct sockaddr_in *)&whereto;
 
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
         opt_complementary = "x-x:g::";
@@ -958,10 +631,10 @@ int traceroute_main(int argc, char **argv)
 #endif
         );
 
-        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)
@@ -988,42 +661,33 @@ int traceroute_main(int argc, char **argv)
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
         if (source_route_list) {
                 while (source_route_list) {
+                        len_and_sockaddr *lsa;
+
                         if (lsrr >= NGATEWAYS)
                                 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
-                        getaddr(gwlist + lsrr, llist_pop(&source_route_list));
+                        lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
+                        gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
+                        free(lsa);
                         ++lsrr;
                 }
                 optlen = (lsrr + 1) * sizeof(gwlist[0]);
         }
 #endif
 
-        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 */
         argv += optind;
         argc -= optind;
         switch (argc) {
         case 2:
-                packlen = xatoul_range(argv[1], minpacket, maxpacket);
+                packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
                 /* Fall through */
         case 1:
-                hostname = argv[0];
-                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();
@@ -1032,8 +696,7 @@ int traceroute_main(int argc, char **argv)
         /* Ensure the socket fds won't be 0, 1 or 2 */
         bb_sanitize_stdio();
 
-        rcvsock = 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(rcvsock, SOL_SOCKET, SO_DEBUG,
@@ -1043,15 +706,17 @@ int traceroute_main(int argc, char **argv)
                 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 */
@@ -1071,24 +736,20 @@ int traceroute_main(int argc, char **argv)
         }
 #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 ((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)
@@ -1099,136 +760,82 @@ 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 (op & OPT_TOS)
-                outip->ip_tos = tos;
-        outip->ip_len = htons(packlen);
-        if (op & OPT_DONT_FRAGMNT)
-                outip->ip_off = htons(IP_DF);
-        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 = (outdata_t *)(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 = (outdata_t *)(outudp + 1);
+                outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
+        } else {
+                outdata = (struct outdata_t *)(outudp + 1);
         }
 
-        /* Look for a specific device */
-        if (op & OPT_DEVICE) {
-                /* Get the interface address list */
-                int n = ifaddrlist(&al);
-                for (; n > 0; --n, ++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) {
-                        uint32_t *ap;
-                        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);
 
         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;
+                        first = 0;
 
-                        while ((cc = wait_for_reply(rcvsock, from)) != 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
+                                 || from.sin_addr.s_addr != lastaddr
                                 ) {
-                                        print(packet, cc, from);
-                                        lastaddr = from->sin_addr.s_addr;
-                                        ++gotlastaddr;
+                                        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) {