]> The Tcpdump Group git mirrors - libpcap/blobdiff - rpcapd/daemon.c
Update config.{guess,sub}, timestamps 2023-01-01,2023-01-21
[libpcap] / rpcapd / daemon.c
index 55e3fa309242469440b5cb2e04c323fad9f731d7..9b0f828515267822a9712fd7d09a0d28070cd2c4 100644 (file)
@@ -197,6 +197,19 @@ struct tls_alert {
 #define TLS_ALERT_LEVEL_FATAL          2
 #define TLS_ALERT_HANDSHAKE_FAILURE    40
 
+static int is_url(const char *source);
+
+/*
+ * Maximum sizes for fixed-bit-width values.
+ */
+#ifndef UINT16_MAX
+#define UINT16_MAX     65535U
+#endif
+
+#ifndef UINT32_MAX
+#define UINT32_MAX     4294967295U
+#endif
+
 int
 daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
     int nullAuthAllowed, int uses_ssl)
@@ -362,7 +375,7 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                                // Immediate EOF
                                goto end;
                        }
-                       plen = (tls_header.length_hi << 8) | tls_header.length_lo;
+                       plen = (tls_header.length_hi << 8U) | tls_header.length_lo;
 
                        // Discard the rest of the message.
                        if (rpcapd_discard(sockctrl, NULL, plen) == -1)
@@ -382,7 +395,7 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                        if (sock_send(sockctrl, NULL, (char *) &tls_header,
                            TLS_RECORD_HEADER_LEN, errbuf, PCAP_ERRBUF_SIZE) == -1)
                        {
-                               // That failed; log a messsage and give up.
+                               // That failed; log a message and give up.
                                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                                goto end;
                        }
@@ -392,7 +405,7 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                        if (sock_send(sockctrl, NULL, (char *) &tls_alert,
                            TLS_ALERT_LEN, errbuf, PCAP_ERRBUF_SIZE) == -1)
                        {
-                               // That failed; log a messsage and give up.
+                               // That failed; log a message and give up.
                                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                                goto end;
                        }
@@ -436,7 +449,8 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                if (getpeername(pars.sockctrl, (struct sockaddr *)&from,
                    &fromlen) == -1)
                {
-                       sock_geterror("getpeername()", errmsgbuf, PCAP_ERRBUF_SIZE);
+                       sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                           "getpeername() failed");
                        if (rpcap_senderror(pars.sockctrl, pars.ssl, 0, PCAP_ERR_NETW, errmsgbuf, errbuf) == -1)
                                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                        goto end;
@@ -510,7 +524,8 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                        retval = select((int)pars.sockctrl + 1, &rfds, NULL, NULL, &tv);
                        if (retval == -1)
                        {
-                               sock_geterror("select() failed", errmsgbuf, PCAP_ERRBUF_SIZE);
+                               sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                                   "select() failed");
                                if (rpcap_senderror(pars.sockctrl, pars.ssl, 0, PCAP_ERR_NETW, errmsgbuf, errbuf) == -1)
                                        rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                                goto end;
@@ -734,7 +749,7 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                //
                // Be carefully: the capture can have been started, but an error occurred (so session != NULL, but
                //  sockdata is 0
-               if ((!pars.isactive) &&  ((session == NULL) || ((session != NULL) && (session->sockdata == 0))))
+               if ((!pars.isactive) && (session == NULL || session->sockdata == 0))
                {
                        // Check for the initial timeout
                        FD_ZERO(&rfds);
@@ -743,11 +758,15 @@ daemon_serviceloop(SOCKET sockctrl, int isactive, char *passiveClients,
                        tv.tv_usec = 0;
 
                        FD_SET(pars.sockctrl, &rfds);
-
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+                       retval = 1;
+#else
                        retval = select((int)pars.sockctrl + 1, &rfds, NULL, NULL, &tv);
+#endif
                        if (retval == -1)
                        {
-                               sock_geterror("select() failed", errmsgbuf, PCAP_ERRBUF_SIZE);
+                               sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                                   "select() failed");
                                if (rpcap_senderror(pars.sockctrl, pars.ssl,
                                    0, PCAP_ERR_NETW,
                                    errmsgbuf, errbuf) == -1)
@@ -1092,6 +1111,9 @@ end:
                session = NULL;
        }
 
+       if (passiveClients) {
+               free(passiveClients);
+       }
        //
        // Finish using the SSL handle for the control socket, if we
        // have an SSL connection, and close the control socket.
@@ -1349,16 +1371,21 @@ daemon_msg_auth_req(struct daemon_slpars *pars, uint32 plen)
                goto error;
 
        //
-       // Indicate to our peer what versions we support.
+       // Indicate to our peer what versions we support and what our
+       // version of the byte-order magic is (which will tell the
+       // client whether our byte order differs from theirs, in which
+       // case they will need to byte-swap some fields in some
+       // link-layer types' headers).
        //
        memset(authreply, 0, sizeof(struct rpcap_authreply));
        authreply->minvers = RPCAP_MIN_VERSION;
        authreply->maxvers = RPCAP_MAX_VERSION;
+       authreply->byte_order_magic = RPCAP_BYTE_ORDER_MAGIC;
 
        // Send the reply.
        if (sock_send(pars->sockctrl, pars->ssl, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) == -1)
        {
-               // That failed; log a messsage and give up.
+               // That failed; log a message and give up.
                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                return -1;
        }
@@ -1412,11 +1439,22 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
         * stop trying to log in with a given user name and move on
         * to another user name.
         */
+       DWORD error;
        HANDLE Token;
+       char errmsgbuf[PCAP_ERRBUF_SIZE];       // buffer for errors to log
+
        if (LogonUser(username, ".", password, LOGON32_LOGON_NETWORK, LOGON32_PROVIDER_DEFAULT, &Token) == 0)
        {
-               pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
-                   GetLastError(), "LogonUser() failed");
+               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
+               error = GetLastError();
+               if (error != ERROR_LOGON_FAILURE)
+               {
+                       // Some error other than an authentication error;
+                       // log it.
+                       pcap_fmt_errmsg_for_win32_err(errmsgbuf,
+                           PCAP_ERRBUF_SIZE, error, "LogonUser() failed");
+                       rpcapd_log(LOGPRIO_ERROR, "%s", errmsgbuf);
+               }
                return -1;
        }
 
@@ -1424,8 +1462,10 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
        // I didn't test it.
        if (ImpersonateLoggedOnUser(Token) == 0)
        {
-               pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
+               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
+               pcap_fmt_errmsg_for_win32_err(errmsgbuf, PCAP_ERRBUF_SIZE,
                    GetLastError(), "ImpersonateLoggedOnUser() failed");
+               rpcapd_log(LOGPRIO_ERROR, "%s", errmsgbuf);
                CloseHandle(Token);
                return -1;
        }
@@ -1437,7 +1477,7 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
        /*
         * See
         *
-        *      http://www.unixpapa.com/incnote/passwd.html
+        *      https://www.unixpapa.com/incnote/passwd.html
         *
         * We use the Solaris/Linux shadow password authentication if
         * we have getspnam(), otherwise we just do traditional
@@ -1453,6 +1493,7 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
         * only password database or some other authentication mechanism,
         * behind its API.
         */
+       int error;
        struct passwd *user;
        char *user_password;
 #ifdef HAVE_GETSPNAM
@@ -1463,7 +1504,7 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
        // This call is needed to get the uid
        if ((user = getpwnam(username)) == NULL)
        {
-               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: user name or password incorrect");
+               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
                return -1;
        }
 
@@ -1471,7 +1512,7 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
        // This call is needed to get the password; otherwise 'x' is returned
        if ((usersp = getspnam(username)) == NULL)
        {
-               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: user name or password incorrect");
+               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
                return -1;
        }
        user_password = usersp->sp_pwdp;
@@ -1489,29 +1530,52 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
        user_password = user->pw_passwd;
 #endif
 
+       //
+       // The Single UNIX Specification says that if crypt() fails it
+       // sets errno, but some implementatons that haven't been run
+       // through the SUS test suite might not do so.
+       //
+       errno = 0;
        crypt_password = crypt(password, user_password);
        if (crypt_password == NULL)
        {
+               error = errno;
                snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
+               if (error == 0)
+               {
+                       // It didn't set errno.
+                       rpcapd_log(LOGPRIO_ERROR, "crypt() failed");
+               }
+               else
+               {
+                       rpcapd_log(LOGPRIO_ERROR, "crypt() failed: %s",
+                           strerror(error));
+               }
                return -1;
        }
        if (strcmp(user_password, crypt_password) != 0)
        {
-               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: user name or password incorrect");
+               snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed");
                return -1;
        }
 
        if (setuid(user->pw_uid))
        {
+               error = errno;
                pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
-                   errno, "setuid");
+                   error, "setuid");
+               rpcapd_log(LOGPRIO_ERROR, "setuid() failed: %s",
+                   strerror(error));
                return -1;
        }
 
 /*     if (setgid(user->pw_gid))
        {
+               error = errno;
                pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
                    errno, "setgid");
+               rpcapd_log(LOGPRIO_ERROR, "setgid() failed: %s",
+                   strerror(error));
                return -1;
        }
 */
@@ -1521,6 +1585,21 @@ daemon_AuthUserPwd(char *username, char *password, char *errbuf)
 
 }
 
+/*
+ * Make sure that the reply length won't overflow 32 bits if we add the
+ * specified amount to it.  If it won't, add that amount to it.
+ *
+ * We check whether replylen + itemlen > UINT32_MAX, but subtract itemlen
+ * from both sides, to prevent overflow.
+ */
+#define CHECK_AND_INCREASE_REPLY_LEN(itemlen) \
+       if (replylen > UINT32_MAX - (itemlen)) { \
+               pcap_strlcpy(errmsgbuf, "Reply length doesn't fit in 32 bits", \
+                   sizeof (errmsgbuf)); \
+               goto error; \
+       } \
+       replylen += (uint32)(itemlen)
+
 static int
 daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
 {
@@ -1531,7 +1610,7 @@ daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
        pcap_if_t *alldevs = NULL;              // pointer to the header of the interface chain
        pcap_if_t *d;                           // temp pointer needed to scan the interface chain
        struct pcap_addr *address;              // pcap structure that keeps a network address of an interface
-       struct rpcap_findalldevs_if *findalldevs_if;// rpcap structure that packet all the data of an interface together
+       uint32 replylen;                        // length of reply payload
        uint16 nif = 0;                         // counts the number of interface listed
 
        // Discard the rest of the message; there shouldn't be any payload.
@@ -1559,18 +1638,37 @@ daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
                return 0;
        }
 
-       // checks the number of interfaces and it computes the total length of the payload
+       // This checks the number of interfaces and computes the total
+       // length of the payload.
+       replylen = 0;
        for (d = alldevs; d != NULL; d = d->next)
        {
                nif++;
 
-               if (d->description)
-                       plen+= strlen(d->description);
-               if (d->name)
-                       plen+= strlen(d->name);
+               if (d->description) {
+                       size_t stringlen = strlen(d->description);
+                       if (stringlen > UINT16_MAX) {
+                               pcap_strlcpy(errmsgbuf,
+                                   "Description length doesn't fit in 16 bits",
+                                   sizeof (errmsgbuf));
+                               goto error;
+                       }
+                       CHECK_AND_INCREASE_REPLY_LEN(stringlen);
+               }
+               if (d->name) {
+                       size_t stringlen = strlen(d->name);
+                       if (stringlen > UINT16_MAX) {
+                               pcap_strlcpy(errmsgbuf,
+                                   "Name length doesn't fit in 16 bits",
+                                   sizeof (errmsgbuf));
+                               goto error;
+                       }
+                       CHECK_AND_INCREASE_REPLY_LEN(stringlen);
+               }
 
-               plen+= sizeof(struct rpcap_findalldevs_if);
+               CHECK_AND_INCREASE_REPLY_LEN(sizeof(struct rpcap_findalldevs_if));
 
+               uint16_t naddrs = 0;
                for (address = d->addresses; address != NULL; address = address->next)
                {
                        /*
@@ -1582,7 +1680,14 @@ daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
 #ifdef AF_INET6
                        case AF_INET6:
 #endif
-                               plen+= (sizeof(struct rpcap_sockaddr) * 4);
+                               CHECK_AND_INCREASE_REPLY_LEN(sizeof(struct rpcap_sockaddr) * 4);
+                               if (naddrs == UINT16_MAX) {
+                                       pcap_strlcpy(errmsgbuf,
+                                           "Number of interfaces doesn't fit in 16 bits",
+                                           sizeof (errmsgbuf));
+                                       goto error;
+                               }
+                               naddrs++;
                                break;
 
                        default:
@@ -1591,37 +1696,50 @@ daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
                }
        }
 
-       // RPCAP findalldevs command
+       // RPCAP findalldevs reply
        if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL,
            &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf,
            PCAP_ERRBUF_SIZE) == -1)
                goto error;
 
        rpcap_createhdr((struct rpcap_header *) sendbuf, ver,
-           RPCAP_MSG_FINDALLIF_REPLY, nif, plen);
+           RPCAP_MSG_FINDALLIF_REPLY, nif, replylen);
 
        // send the interface list
        for (d = alldevs; d != NULL; d = d->next)
        {
                uint16 lname, ldescr;
 
-               findalldevs_if = (struct rpcap_findalldevs_if *) &sendbuf[sendbufidx];
-
-               if (sock_bufferize(NULL, sizeof(struct rpcap_findalldevs_if), NULL,
-                   &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1)
-                       goto error;
-
-               memset(findalldevs_if, 0, sizeof(struct rpcap_findalldevs_if));
+               // Note: the findalldevs_if entries are *not* neatly
+               // aligned on 4-byte boundaries, because they're
+               // preceded by strings that aren't padded to 4-byte
+               // boundaries, so we cannot just cast output buffer
+               // boundaries to struct rpcap_findalldevs_if pointers
+               // and store into them - we must fill in a structure and
+               // then copy the structure to the buffer, as not all
+               // systems support unaligned access (some, such as
+               // SPARC, crash; others, such as Arm, may just ignore
+               // the lower-order bits).
+               struct rpcap_findalldevs_if findalldevs_if;
 
-               if (d->description) ldescr = (short) strlen(d->description);
-               else ldescr = 0;
-               if (d->name) lname = (short) strlen(d->name);
-               else lname = 0;
+               /*
+                * We've already established that the string lengths
+                * fit in 16 bits.
+                */
+               if (d->description)
+                       ldescr = (uint16) strlen(d->description);
+               else
+                       ldescr = 0;
+               if (d->name)
+                       lname = (uint16) strlen(d->name);
+               else
+                       lname = 0;
 
-               findalldevs_if->desclen = htons(ldescr);
-               findalldevs_if->namelen = htons(lname);
-               findalldevs_if->flags = htonl(d->flags);
+               findalldevs_if.desclen = htons(ldescr);
+               findalldevs_if.namelen = htons(lname);
+               findalldevs_if.flags = htonl(d->flags);
 
+               uint16_t naddrs = 0;
                for (address = d->addresses; address != NULL; address = address->next)
                {
                        /*
@@ -1633,14 +1751,20 @@ daemon_msg_findallif_req(uint8 ver, struct daemon_slpars *pars, uint32 plen)
 #ifdef AF_INET6
                        case AF_INET6:
 #endif
-                               findalldevs_if->naddr++;
+                               naddrs++;
                                break;
 
                        default:
                                break;
                        }
                }
-               findalldevs_if->naddr = htons(findalldevs_if->naddr);
+               findalldevs_if.naddr = htons(naddrs);
+               findalldevs_if.dummy = 0;
+
+               if (sock_bufferize(&findalldevs_if, sizeof(struct rpcap_findalldevs_if), sendbuf,
+                   &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errmsgbuf,
+                   PCAP_ERRBUF_SIZE) == -1)
+                       goto error;
 
                if (sock_bufferize(d->name, lname, sendbuf, &sendbufidx,
                    RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errmsgbuf,
@@ -1754,14 +1878,19 @@ daemon_msg_open_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
        source[nread] = '\0';
        plen -= nread;
 
-       // XXX - make sure it's *not* a URL; we don't support opening
-       // remote devices here.
+       // Is this a URL rather than a device?
+       // If so, reject it.
+       if (is_url(source))
+       {
+               snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Source string refers to a remote device");
+               goto error;
+       }
 
        // Open the selected device
        // This is a fake open, since we do that only to get the needed parameters, then we close the device again
        if ((fp = pcap_open_live(source,
                        1500 /* fake snaplen */,
-                       0 /* no promis */,
+                       0 /* no promisc */,
                        1000 /* fake timeout */,
                        errmsgbuf)) == NULL)
                goto error;
@@ -1933,7 +2062,8 @@ daemon_msg_startcap_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
        saddrlen = sizeof(struct sockaddr_storage);
        if (getpeername(pars->sockctrl, (struct sockaddr *) &saddr, &saddrlen) == -1)
        {
-               sock_geterror("getpeername()", errmsgbuf, PCAP_ERRBUF_SIZE);
+               sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                   "getpeername() failed");
                goto error;
        }
 
@@ -1950,32 +2080,34 @@ daemon_msg_startcap_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
                if (getnameinfo((struct sockaddr *) &saddr, saddrlen, peerhost,
                                sizeof(peerhost), NULL, 0, NI_NUMERICHOST))
                {
-                       sock_geterror("getnameinfo()", errmsgbuf, PCAP_ERRBUF_SIZE);
+                       sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                           "getnameinfo() failed");
                        goto error;
                }
 
                if (sock_initaddress(peerhost, portdata, &hints, &addrinfo, errmsgbuf, PCAP_ERRBUF_SIZE) == -1)
                        goto error;
 
-               if ((session->sockdata = sock_open(addrinfo, SOCKOPEN_CLIENT, 0, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET)
+               if ((session->sockdata = sock_open(peerhost, addrinfo, SOCKOPEN_CLIENT, 0, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET)
                        goto error;
        }
        else            // Data connection is opened by the client toward the server
        {
                hints.ai_flags = AI_PASSIVE;
 
-               // Let's the server socket pick up a free network port for us
-               if (sock_initaddress(NULL, "0", &hints, &addrinfo, errmsgbuf, PCAP_ERRBUF_SIZE) == -1)
+               // Make the server socket pick up a free network port for us
+               if (sock_initaddress(NULL, NULL, &hints, &addrinfo, errmsgbuf, PCAP_ERRBUF_SIZE) == -1)
                        goto error;
 
-               if ((session->sockdata = sock_open(addrinfo, SOCKOPEN_SERVER, 1 /* max 1 connection in queue */, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET)
+               if ((session->sockdata = sock_open(NULL, addrinfo, SOCKOPEN_SERVER, 1 /* max 1 connection in queue */, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET)
                        goto error;
 
                // get the complete sockaddr structure used in the data connection
                saddrlen = sizeof(struct sockaddr_storage);
                if (getsockname(session->sockdata, (struct sockaddr *) &saddr, &saddrlen) == -1)
                {
-                       sock_geterror("getsockname()", errmsgbuf, PCAP_ERRBUF_SIZE);
+                       sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                           "getsockname() failed");
                        goto error;
                }
 
@@ -1983,7 +2115,8 @@ daemon_msg_startcap_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
                if (getnameinfo((struct sockaddr *) &saddr, saddrlen, NULL,
                                0, portdata, sizeof(portdata), NI_NUMERICSERV))
                {
-                       sock_geterror("getnameinfo()", errmsgbuf, PCAP_ERRBUF_SIZE);
+                       sock_geterrmsg(errmsgbuf, PCAP_ERRBUF_SIZE,
+                           "getnameinfo() failed");
                        goto error;
                }
        }
@@ -2051,7 +2184,8 @@ daemon_msg_startcap_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
 
                if (socktemp == INVALID_SOCKET)
                {
-                       sock_geterror("accept()", errbuf, PCAP_ERRBUF_SIZE);
+                       sock_geterrmsg(errbuf, PCAP_ERRBUF_SIZE,
+                          "accept() failed");
                        rpcapd_log(LOGPRIO_ERROR, "Accept of data connection failed: %s",
                            errbuf);
                        goto error;
@@ -2177,6 +2311,23 @@ daemon_msg_endcap_req(uint8 ver, struct daemon_slpars *pars,
        return 0;
 }
 
+//
+// We impose a limit on the filter program size, so that, on Windows,
+// where there's only one server process with multiple threads, it's
+// harder to eat all the server address space by sending larger filter
+// programs.  (This isn't an issue on UN*X, where there are multiple
+// server processes, one per client connection.)
+//
+// We pick a value that limits each filter to 64K; that value is twice
+// the in-kernel limit for Linux and 16 times the in-kernel limit for
+// *BSD and macOS.
+//
+// It also prevents an overflow on 32-bit platforms when calculating
+// the total size of the filter program.  (It's not an issue on 64-bit
+// platforms with a 64-bit size_t, as the filter size is 32 bits.)
+//
+#define RPCAP_BPF_MAXINSNS     8192
+
 static int
 daemon_unpackapplyfilter(SOCKET sockctrl, SSL *ctrl_ssl, struct session *session, uint32 *plenp, char *errmsgbuf)
 {
@@ -2206,6 +2357,13 @@ daemon_unpackapplyfilter(SOCKET sockctrl, SSL *ctrl_ssl, struct session *session
                return -2;
        }
 
+       if (bf_prog.bf_len > RPCAP_BPF_MAXINSNS)
+       {
+               snprintf(errmsgbuf, PCAP_ERRBUF_SIZE,
+                   "Filter program is larger than the maximum size of %d instructions",
+                   RPCAP_BPF_MAXINSNS);
+               return -2;
+       }
        bf_insn = (struct bpf_insn *) malloc (sizeof(struct bpf_insn) * bf_prog.bf_len);
        if (bf_insn == NULL)
        {
@@ -2286,9 +2444,9 @@ daemon_msg_updatefilter_req(uint8 ver, struct daemon_slpars *pars,
        // A response is needed, otherwise the other host does not know that everything went well
        rpcap_createhdr(&header, ver, RPCAP_MSG_UPDATEFILTER_REPLY, 0, 0);
 
-       if (sock_send(pars->sockctrl, pars->ssl, (char *) &header, sizeof (struct rpcap_header), pcap_geterr(session->fp), PCAP_ERRBUF_SIZE))
+       if (sock_send(pars->sockctrl, pars->ssl, (char *) &header, sizeof (struct rpcap_header), errbuf, PCAP_ERRBUF_SIZE))
        {
-               // That failed; log a messsage and give up.
+               // That failed; log a message and give up.
                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                return -1;
        }
@@ -2338,7 +2496,7 @@ daemon_msg_setsampling_req(uint8 ver, struct daemon_slpars *pars, uint32 plen,
 
        if (sock_send(pars->sockctrl, pars->ssl, (char *) &header, sizeof (struct rpcap_header), errbuf, PCAP_ERRBUF_SIZE) == -1)
        {
-               // That failed; log a messsage and give up.
+               // That failed; log a message and give up.
                rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf);
                return -1;
        }
@@ -2683,19 +2841,25 @@ daemon_seraddr(struct sockaddr_storage *sockaddrin, struct rpcap_sockaddr *socka
        if (sockaddrin == NULL) return;
 
        // Warning: we support only AF_INET and AF_INET6
+       //
+       // Note: as noted above, the output structures are not
+       // neatly aligned on 4-byte boundaries, so we must fill
+       // in an aligned structure and then copy it to the output
+       // buffer with memcpy().
        switch (sockaddrin->ss_family)
        {
        case AF_INET:
                {
                struct sockaddr_in *sockaddrin_ipv4;
-               struct rpcap_sockaddr_in *sockaddrout_ipv4;
+               struct rpcap_sockaddr_in sockaddrout_ipv4;
 
                sockaddrin_ipv4 = (struct sockaddr_in *) sockaddrin;
-               sockaddrout_ipv4 = (struct rpcap_sockaddr_in *) sockaddrout;
-               sockaddrout_ipv4->family = htons(RPCAP_AF_INET);
-               sockaddrout_ipv4->port = htons(sockaddrin_ipv4->sin_port);
-               memcpy(&sockaddrout_ipv4->addr, &sockaddrin_ipv4->sin_addr, sizeof(sockaddrout_ipv4->addr));
-               memset(sockaddrout_ipv4->zero, 0, sizeof(sockaddrout_ipv4->zero));
+
+               sockaddrout_ipv4.family = htons(RPCAP_AF_INET);
+               sockaddrout_ipv4.port = htons(sockaddrin_ipv4->sin_port);
+               memcpy(&sockaddrout_ipv4.addr, &sockaddrin_ipv4->sin_addr, sizeof(sockaddrout_ipv4.addr));
+               memset(sockaddrout_ipv4.zero, 0, sizeof(sockaddrout_ipv4.zero));
+               memcpy(sockaddrout, &sockaddrout_ipv4, sizeof(struct rpcap_sockaddr_in));
                break;
                }
 
@@ -2703,15 +2867,16 @@ daemon_seraddr(struct sockaddr_storage *sockaddrin, struct rpcap_sockaddr *socka
        case AF_INET6:
                {
                struct sockaddr_in6 *sockaddrin_ipv6;
-               struct rpcap_sockaddr_in6 *sockaddrout_ipv6;
+               struct rpcap_sockaddr_in6 sockaddrout_ipv6;
 
                sockaddrin_ipv6 = (struct sockaddr_in6 *) sockaddrin;
-               sockaddrout_ipv6 = (struct rpcap_sockaddr_in6 *) sockaddrout;
-               sockaddrout_ipv6->family = htons(RPCAP_AF_INET6);
-               sockaddrout_ipv6->port = htons(sockaddrin_ipv6->sin6_port);
-               sockaddrout_ipv6->flowinfo = htonl(sockaddrin_ipv6->sin6_flowinfo);
-               memcpy(&sockaddrout_ipv6->addr, &sockaddrin_ipv6->sin6_addr, sizeof(sockaddrout_ipv6->addr));
-               sockaddrout_ipv6->scope_id = htonl(sockaddrin_ipv6->sin6_scope_id);
+
+               sockaddrout_ipv6.family = htons(RPCAP_AF_INET6);
+               sockaddrout_ipv6.port = htons(sockaddrin_ipv6->sin6_port);
+               sockaddrout_ipv6.flowinfo = htonl(sockaddrin_ipv6->sin6_flowinfo);
+               memcpy(&sockaddrout_ipv6.addr, &sockaddrin_ipv6->sin6_addr, sizeof(sockaddrout_ipv6.addr));
+               sockaddrout_ipv6.scope_id = htonl(sockaddrin_ipv6->sin6_scope_id);
+               memcpy(sockaddrout, &sockaddrout_ipv6, sizeof(struct rpcap_sockaddr_in6));
                break;
                }
 #endif
@@ -2724,6 +2889,7 @@ daemon_seraddr(struct sockaddr_storage *sockaddrin, struct rpcap_sockaddr *socka
 */
 void sleep_secs(int secs)
 {
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 #ifdef _WIN32
        Sleep(secs*1000);
 #else
@@ -2735,6 +2901,7 @@ void sleep_secs(int secs)
        while (secs_remaining != 0)
                secs_remaining = sleep(secs_remaining);
 #endif
+#endif
 }
 
 /*
@@ -2913,3 +3080,67 @@ static void session_close(struct session *session)
                session->fp = NULL;
        }
 }
+
+//
+// Check whether a capture source string is a URL or not.
+// This includes URLs that refer to a local device; a scheme, followed
+// by ://, followed by *another* scheme and ://, is just silly, and
+// anybody who supplies that will get an error.
+//
+static int
+is_url(const char *source)
+{
+       char *colonp;
+
+       /*
+        * RFC 3986 says:
+        *
+        *   URI         = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
+        *
+        *   hier-part   = "//" authority path-abempty
+        *               / path-absolute
+        *               / path-rootless
+        *               / path-empty
+        *
+        *   authority   = [ userinfo "@" ] host [ ":" port ]
+        *
+        *   userinfo    = *( unreserved / pct-encoded / sub-delims / ":" )
+        *
+        * Step 1: look for the ":" at the end of the scheme.
+        * A colon in the source is *NOT* sufficient to indicate that
+        * this is a URL, as interface names on some platforms might
+        * include colons (e.g., I think some Solaris interfaces
+        * might).
+        */
+       colonp = strchr(source, ':');
+       if (colonp == NULL)
+       {
+               /*
+                * The source is the device to open.  It's not a URL.
+                */
+               return (0);
+       }
+
+       /*
+        * All schemes must have "//" after them, i.e. we only support
+        * hier-part   = "//" authority path-abempty, not
+        * hier-part   = path-absolute
+        * hier-part   = path-rootless
+        * hier-part   = path-empty
+        *
+        * We need that in order to distinguish between a local device
+        * name that happens to contain a colon and a URI.
+        */
+       if (strncmp(colonp + 1, "//", 2) != 0)
+       {
+               /*
+                * The source is the device to open.  It's not a URL.
+                */
+               return (0);
+       }
+
+       /*
+        * It's a URL.
+        */
+       return (1);
+}