dnsbl: src/dnsbl.cpp comparison

comparison src/dnsbl.cpp @ 60:390ed250c5d2 stable-4-1

use local unix domain socket for resolver process communication

author	carl
date	Thu, 06 Jan 2005 11:35:38 -0800
parents	510a511ad554
children	7f44a4974bf6

comparison

equal deleted inserted replaced

-:510a511ad554
+:390ed250c5d2
 static pthread_mutex_t  resolve_mutex;
 static pthread_mutex_t  fd_pool_mutex;
 static std::set<int>    fd_pool;
 static int    NULL_SOCKET       = -1;
-static int    resolver_port     = 0;            // global port number to talk to the dns resolver process
+static char  *resolver_port     = NULL;         // unix domain socket to talk to the dns resolver process
 static int    resolver_socket   = NULL_SOCKET;  // socket used to listen for resolver requests
 static time_t ERROR_SOCKET_TIME = 60;           // number of seconds between attempts to open the spam filter socket
 static time_t last_error_time;
 #ifdef NS_PACKETSZ
 time_t now = time(NULL);
 if ((now - last_error_time) < ERROR_SOCKET_TIME) return NULL_SOCKET;
 // nothing recent, maybe this time it will work
 int sock = NULL_SOCKET;
-hostent *host = gethostbyname("localhost");
+sockaddr_un server;
-if (host) {
+memset(&server, '\0', sizeof(server));
-sockaddr_in server;
+server.sun_family = AF_UNIX;
-server.sin_family = host->h_addrtype;
+strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1);
-server.sin_port   = htons(resolver_port);
+sock = socket(AF_UNIX, SOCK_STREAM, 0);
-memcpy(&server.sin_addr, host->h_addr_list[0], host->h_length);
+if (sock != NULL_SOCKET) {
-sock = socket(PF_INET, SOCK_STREAM, 0);
+bool rc = (connect(sock, (sockaddr *)&server, sizeof(server)) == 0);
-if (sock != NULL_SOCKET) {
+if (!rc) {
-bool rc = (connect(sock, (sockaddr *)&server, sizeof(server)) == 0);
+int er = errno;
-if (!rc) {
+my_disconnect(sock);
-int er = errno;
+sock = NULL_SOCKET;
-my_disconnect(sock);
+last_error_time = now;
-sock = NULL_SOCKET;
+}
-last_error_time = now;
+}
-}
+else last_error_time = now;
-}
-else last_error_time = now;
-}
 return sock;
 }
 ////////////////////////////////////////////////
 break;
 }
 }
 else {
 // peer closed the socket
-//my_syslog("child worker process, peer closed socket while reading question");
+//my_syslog("!!child worker process, peer closed socket while reading question");
 shutdown(socket, SHUT_RDWR);
 close(socket);
 return;
 }
 }
 // find the answer
 //char text[1000];
-//snprintf(text, sizeof(text), "child worker process has a question %s", question);
+//snprintf(text, sizeof(text), "!!child worker process has a question %s", question);
 //my_syslog(text);
 glom.length = res_search(question, ns_c_in, ns_t_a, glom.answer, sizeof(glom.answer));
 if (glom.length < 0) glom.length = 0;   // represent all errors as zero length answers
 // write the answer
 char *buf = (char *)&glom;
 int   len = glom.length + sizeof(glom.length);
-//snprintf(text, sizeof(text), "child worker process writing answer length %d for total %d", glom.length, len);
+//snprintf(text, sizeof(text), "!!child worker process writing answer length %d for total %d", glom.length, len);
 //my_syslog(text);
 int    ws = 0;
 while (len > ws) {
 int ns = write(socket, buf+ws, len-ws);
 if (ns > 0) {
 ws += ns;
 }
 else {
 // peer closed the socket!
-//my_syslog("child worker process, peer closed socket while writing answer");
+//my_syslog("!!child worker process, peer closed socket while writing answer");
 shutdown(socket, SHUT_RDWR);
 close(socket);
 return;
 }
 }
 priv.my_write(question, strlen(question)+1);   // write the question including the null terminator
 glommer glom;
 char *buf = (char *)&glom;
 priv.my_read(buf, sizeof(glom.length));
 buf += sizeof(glom.length);
-//char text[1000];
+///char text[1000];
-//snprintf(text, sizeof(text), "milter thread wrote question %s and has answer length %d", question, glom.length);
+///snprintf(text, sizeof(text), "!!milter thread wrote question %s and has answer length %d", question, glom.length);
-//my_syslog(text);
+///my_syslog(text);
 if ((glom.length < 0) || (glom.length > sizeof(glom.answer))) {
 priv.err = true;
 return 0;  // cannot process overlarge answers
 }
 priv.my_read(buf, glom.length);
 static void usage(char *prog);
 static void usage(char *prog)
 {
 fprintf(stderr, "Usage: %s  [-d] [-c] -r port -p sm-sock-addr [-t timeout]\n", prog);
 fprintf(stderr, "where port is for the connection to our own dns resolver processes\n");
+fprintf(stderr, "    and should be local-domain-socket-file-name\n");
 fprintf(stderr, "where sm-sock-addr is for the connection to sendmail\n");
 fprintf(stderr, "    and should be one of\n");
 fprintf(stderr, "        inet:port@ip-address\n");
 fprintf(stderr, "        local:local-domain-socket-file-name\n");
 fprintf(stderr, "-c will load and dump the config to stdout\n");
 static void setup_socket(char *sock);
 static void setup_socket(char *sock) {
 unlink(sock);
-// sockaddr_un addr;
+//  sockaddr_un addr;
-// memset(&addr, '\0', sizeof addr);
+//  memset(&addr, '\0', sizeof addr);
-// addr.sun_family = AF_UNIX;
+//  addr.sun_family = AF_UNIX;
-// strncpy(addr.sun_path, sock, sizeof(addr.sun_path)-1);
+//  strncpy(addr.sun_path, sock, sizeof(addr.sun_path)-1);
-// int s = socket(AF_UNIX, SOCK_STREAM, 0);
+//  int s = socket(AF_UNIX, SOCK_STREAM, 0);
-// bind(s, (sockaddr*)&addr, sizeof(addr));
+//  bind(s, (sockaddr*)&addr, sizeof(addr));
-// close(s);
+//  close(s);
 }
 int main(int argc, char**argv)
 {
 case 'r':
 if (optarg == NULL || *optarg == '\0') {
 fprintf(stderr, "Illegal resolver socket: %s\n", optarg);
 exit(EX_USAGE);
 }
-resolver_port = atoi(optarg);
+resolver_port = strdup(optarg);
+setup_socket(resolver_port);
 setreso = true;
 break;
 case 'p':
 if (optarg == NULL || *optarg == '\0') {
 pthread_mutex_init(&config_mutex, 0);
 pthread_mutex_init(&syslog_mutex, 0);
 pthread_mutex_init(&resolve_mutex, 0);
 pthread_mutex_init(&fd_pool_mutex, 0);
+// drop root privs
+struct passwd *pw = getpwnam("dnsbl");
+if (pw) {
+if (setgid(pw->pw_gid) == -1) {
+my_syslog("failed to switch to group dnsbl");
+}
+if (setuid(pw->pw_uid) == -1) {
+my_syslog("failed to switch to user dnsbl");
+}
+}
 #ifdef NS_PACKETSZ
 // fork off the resolver listener process
 pid_t child = fork();
 if (child < 0) {
 my_syslog("failed to create resolver listener process");
 exit(0);
 }
 if (child == 0) {
 // we are the child - dns resolver listener process
-resolver_socket = socket(PF_INET, SOCK_STREAM, 0);
+resolver_socket = socket(AF_UNIX, SOCK_STREAM, 0);
 if (resolver_socket < 0) {
 my_syslog("child failed to create resolver socket");
 exit(0);   // failed
 }
-sockaddr_in server;
+sockaddr_un server;
-server.sin_family   = AF_INET;
+memset(&server, '\0', sizeof(server));
-server.sin_port     = htons(resolver_port);
+server.sun_family = AF_UNIX;
-server.sin_addr.s_addr = 0;
+strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1);
 // set the socket options
-int      reuse_addr = 1;
+///int      reuse_addr = 1;
-linger linger_opt;
+///linger linger_opt;
-linger_opt.l_onoff  = 0;    // off
+///linger_opt.l_onoff  = 0;    // off
-linger_opt.l_linger = 0;
+///linger_opt.l_linger = 0;
-setsockopt(resolver_socket, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<char*>(&reuse_addr), sizeof(reuse_addr));
+///setsockopt(resolver_socket, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<char*>(&reuse_addr), sizeof(reuse_addr));
-setsockopt(resolver_socket, SOL_SOCKET, SO_LINGER,    reinterpret_cast<char*>(&linger_opt), sizeof(linger_opt));
+///setsockopt(resolver_socket, SOL_SOCKET, SO_LINGER,    reinterpret_cast<char*>(&linger_opt), sizeof(linger_opt));
 ///// set nonblocking mode
 ///int     dummy = 0;
 ///int     flags = fcntl(resolver_socket, F_GETFL, dummy);
 ///if (flags >= 0) fcntl(resolver_socket, F_SETFL, flags | O_NONBLOCK);
 //try to bind the address to the socket.
 if (listen(resolver_socket, 10) < 0) {
 // listen failed
 shutdown(resolver_socket, SHUT_RDWR);
 close(resolver_socket);
 my_syslog("child failed to listen to the resolver socket");
-return -1;
+exit(0);   // failed
 }
-}
-else {
-sleep(2);   // allow child to get started
-}
-#endif
-// drop root privs
-struct passwd *pw = getpwnam("dnsbl");
-if (pw) {
-if (setgid(pw->pw_gid) == -1) {
-my_syslog("failed to switch to group dnsbl");
-}
-if (setuid(pw->pw_uid) == -1) {
-my_syslog("failed to switch to user dnsbl");
-}
-}
-#ifdef NS_PACKETSZ
-if (child == 0) {
 while (true) {
-sockaddr_in client;
+sockaddr_un client;
 socklen_t   clientlen = sizeof(client);
 int s = accept(resolver_socket, (sockaddr *)&client, &clientlen);
 if (s > 0) {
 // accept worked, it did not get cancelled before we could accept it
 // fork off a process to handle this connection
 int newchild = fork();
 if (newchild == 0) {
 // this is the worker process
+// child does not need the listening socket
+close(resolver_socket);
 my_syslog("child forked a worker process");
 process_resolver_requests(s);
 my_syslog("child terminated a worker process");
 exit(0);
 }
+else {
+// this is the parent
+// parent does not need the accepted socket
+close(s);
+}
 }
 }
 exit(0);    // make sure we don't fall thru.
+}
+else {
+sleep(2);   // allow child to get started
 }
 #endif
 // load the initial config
 config = new_conf();

Mercurial > dnsbl

comparison src/dnsbl.cpp @ 60:390ed250c5d2 stable-4-1