initial release

src/piler.c

@@ -0,0 +1,249 @@
+/*
+ * piler.c, SJ
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <signal.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+#include <locale.h>
+#include <errno.h>
+#include <piler.h>
+
+
+extern char *optarg;
+extern int optind;
+
+int sd;
+int nconn = 0;
+char *configfile = CONFIG_FILE;
+struct __config cfg;
+struct __data data;
+struct passwd *pwd;
+
+
+void clean_exit(){
+   if(sd != -1) close(sd);
+
+   freeList(data.blackhole);
+
+   syslog(LOG_PRIORITY, "%s has been terminated", PROGNAME);
+
+   unlink(cfg.pidfile);
+
+   exit(1);
+}
+
+
+void fatal(char *s){
+   syslog(LOG_PRIORITY, "%s\n", s);
+   clean_exit();
+}
+
+
+void sigchld(){
+   int pid, wstat;
+
+   while((pid = wait_nohang(&wstat)) > 0){
+      if(nconn > 0) nconn--;
+   }
+}
+
+
+void initialiseConfiguration(){
+
+   cfg = read_config(configfile);
+
+   if(strlen(cfg.username) > 1){
+      pwd = getpwnam(cfg.username);
+      if(!pwd) fatal(ERR_NON_EXISTENT_USER);
+   }
+
+
+   if(getuid() == 0 && pwd){
+      check_and_create_directories(&cfg, pwd->pw_uid, pwd->pw_gid);
+   }
+
+
+   if(chdir(cfg.workdir)){
+      syslog(LOG_PRIORITY, "workdir: *%s*", cfg.workdir);
+      fatal(ERR_CHDIR);
+   }
+
+   setlocale(LC_MESSAGES, cfg.locale);
+   setlocale(LC_CTYPE, cfg.locale);
+
+   freeList(data.blackhole);
+   data.blackhole = NULL;
+
+   syslog(LOG_PRIORITY, "reloaded config: %s", configfile);
+
+#ifdef HAVE_MEMCACHED
+   memcached_init(&(data.memc), cfg.memcached_servers, 11211);
+#endif
+}
+
+
+int read_key(struct __config *cfg){
+   int fd, n;
+
+   fd = open(KEYFILE, O_RDONLY);
+   if(fd == -1){
+      syslog(LOG_PRIORITY, "cannot read keyfile: %s", KEYFILE);
+      return -1;
+   }
+
+   n = read(fd, cfg->key, KEYLEN);
+
+   close(fd);
+
+   if(n > 5) return 0;
+
+   return 1;
+}
+
+
+int main(int argc, char **argv){
+   int i, new_sd, yes=1, pid, daemonise=0;
+   unsigned int clen;
+   struct sockaddr_in client_addr, serv_addr;
+   struct in_addr addr;
+
+   while((i = getopt(argc, argv, "c:dvVh")) > 0){
+      switch(i){
+
+        case 'c' :
+                   configfile = optarg;
+                   break;
+
+        case 'd' :
+                   daemonise = 1;
+                   break;
+
+        case 'v' :
+        case 'V' :
+                   __fatal(PROGNAME " " PROGINFO);
+                   break;
+
+        case 'h' :
+        default  : 
+                   __fatal("usage: ...");
+      }
+   }
+
+   (void) openlog(PROGNAME, LOG_PID, LOG_MAIL);
+
+   sig_catch(SIGINT, clean_exit);
+   sig_catch(SIGQUIT, clean_exit);
+   sig_catch(SIGKILL, clean_exit);
+   sig_catch(SIGTERM, clean_exit);
+   sig_catch(SIGHUP, initialiseConfiguration);
+
+
+   data.blackhole = NULL;
+
+
+   sig_block(SIGCHLD);
+   sig_catch(SIGCHLD, sigchld);
+
+
+   initialiseConfiguration();
+
+
+   if(read_key(&cfg)) fatal(ERR_READING_KEY);
+
+
+   if((sd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
+      fatal(ERR_OPEN_SOCKET);
+
+   serv_addr.sin_family = AF_INET;
+   serv_addr.sin_port = htons(cfg.listen_port);
+   inet_aton(cfg.listen_addr, &addr);
+   serv_addr.sin_addr.s_addr = addr.s_addr;
+   bzero(&(serv_addr.sin_zero), 8);
+
+   if(setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1)
+      fatal(ERR_SET_SOCK_OPT);
+
+   if(bind(sd, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr)) == -1)
+      fatal(ERR_BIND_TO_PORT);
+
+   if(listen(sd, cfg.backlog) == -1)
+      fatal(ERR_LISTEN);
+
+
+   if(drop_privileges(pwd)) fatal(ERR_SETUID);
+
+
+   syslog(LOG_PRIORITY, "%s %s starting", PROGNAME, VERSION);
+
+
+#if HAVE_DAEMON == 1
+   if(daemonise == 1) i = daemon(1, 0);
+#endif
+
+   write_pid_file(cfg.pidfile);
+
+
+   /* main accept loop */
+
+   for(;;){
+
+      /* let new connections wait if we are too busy now */
+
+      if(nconn >= cfg.max_connections) sig_pause();
+
+      clen = sizeof(client_addr);
+
+      sig_unblock(SIGCHLD);
+      new_sd = accept(sd, (struct sockaddr *)&client_addr, &clen);
+      sig_block(SIGCHLD);
+
+      if(new_sd == -1) continue;
+
+      pid = fork();
+
+      if(pid == 0){
+          sig_uncatch(SIGCHLD);
+          sig_unblock(SIGCHLD);
+
+          sig_uncatch(SIGINT);
+          sig_uncatch(SIGQUIT);
+          sig_uncatch(SIGKILL);
+          sig_uncatch(SIGTERM);
+          sig_block(SIGHUP);
+
+          syslog(LOG_PRIORITY, "connection from client: %s", inet_ntoa(client_addr.sin_addr));
+
+          handle_smtp_session(new_sd, &data, &cfg);
+
+          _exit(0);
+      }
+
+      else if(pid > 0){
+         nconn++;
+      }
+
+      else {
+         syslog(LOG_PRIORITY, "%s", ERR_FORK_FAILED);
+      }
+
+      close(new_sd);
+   }
+
+   return 0;
+}
+