X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=inn-innduct.git;a=blobdiff_plain;f=backends%2Finnduct.c;h=0e0b0edeeca2c01b11a820a2b977b3ae56b9b077;hp=7fa943d638c4852364c0bc5bef3b9a7608b4b9c3;hb=f7573c26c1935719413e79cb82068da35a27b16b;hpb=55cb8dcfa035728631492596baa74844d98c20d0

diff --git a/backends/innduct.c b/backends/innduct.c
index 7fa943d..0e0b0ed 100644
--- a/backends/innduct.c
+++ b/backends/innduct.c
@@ -1,3 +1,9 @@
+/*
+ * TODO
+ *  - close idle connections
+ *  - -k kill mode ?
+ */
+
 /*
  * Newsfeeds file entries should look like this:
  *     host.name.of.site[/exclude,exclude,...]\
@@ -145,6 +151,34 @@ perl -ne 'print if m/-8\<-/..m/-\>8-/; print "\f" if m/-\^L-/' backends/innduct.
  *
  */
 
+/*============================== PROGRAM ==============================*/
+
+#define _GNU_SOURCE
+
+#include "inn/list.h"
+#include "config.h"
+#include "storage.h"
+#include "nntp.h"
+#include "libinn.h"
+
+#include <sys/uio.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <stdio.h>
+#include <errno.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#include <oop.h>
+#include <oop-read.h>
 
 /*----- general definitions, probably best not changed -----*/
 
@@ -156,12 +190,91 @@ perl -ne 'print if m/-8\<-/..m/-\>8-/; print "\f" if m/-\^L-/' backends/innduct.
 #define INNDCOMMCHILD_ESTATUS_FAIL     6
 #define INNDCOMMCHILD_ESTATUS_NONESUCH 7
 
+/*----- doubly linked lists -----*/
+
+#define ISNODE(T)   struct { T *succ, *pred; } node  /* must be at start */
+#define DEFLIST(T)  typedef struct { T *hd, *tl, *tp; int count; } T##List
+
+#define NODE(n) (assert((void*)&(n)->node == &(n)), \
+		 (struct node*)&(n)->node)
+
+#define LIST_CHECKCANHAVENODE(l,n) \
+  ((void)((n) == ((l).hd))) /* just for the type check */
+
+#define LIST_ADDSOMEHOW(l,n,list_addsomehow)		\
+ ( LIST_CHECKCANHAVENODE(l,n),				\
+   list_addsomehow((struct list*)&(l), NODE((n))),	\
+   (void)(l).count++					\
+   )
+
+#define LIST_REMSOMEHOW(l,list_remsomehow)	\
+ ( (typeof((l).hd))				\
+   ( (l).count					\
+     ? ( (l).count--,				\
+	 list_remsomehow((struct list*)&(l)) )	\
+     : 0					\
+     )						\
+   )
+
+
+#define LIST_ADDHEAD(l,n) LIST_ADDSOMEHOW((l),(n),list_addhead)
+#define LIST_ADDTAIL(l,n) LIST_ADDSOMEHOW((l),(n),list_addtail)
+#define LIST_REMHEAD(l) LIST_REMSOMEHOW((l),list_remhead)
+#define LIST_REMTAIL(l) LIST_REMSOMEHOW((l),list_remtail)
+
+#define LIST_HEAD(l) ((typeof((l).hd))(list_head((struct list*)&(l))))
+#define LIST_NEXT(n) ((typeof(n))list_succ(NODE((n))))
+#define LIST_BACK(n) ((typeof(n))list_pred(NODE((n))))
+
+#define LIST_REMOVE(l,n)			\
+ ( LIST_CHECKCANHAVENODE(l,n),			\
+   list_remove(NODE((n))),			\
+   (void)(l).count--				\
+   )
+
+#define LIST_INSERT(l,n,pred)					\
+ ( LIST_CHECKCANHAVENODE(l,n),					\
+   LIST_CHECKCANHAVENODE(l,pred),				\
+   list_insert((struct list*)&(l), NODE((n)), NODE((pred))),	\
+   (void)(l).count++						\
+   )
+
+/*----- type predeclarations -----*/
+
+typedef struct Conn Conn;
+typedef struct Article Article;
+typedef struct InputFile InputFile;
+typedef struct XmitDetails XmitDetails;
+typedef enum StateMachineState StateMachineState;
+
+DEFLIST(Conn);
+DEFLIST(Article);
+
+/*----- function predeclarations -----*/
+
+static void conn_maybe_write(Conn *conn);
+static void conn_make_some_xmits(Conn *conn);
+static void *conn_write_some_xmits(Conn *conn);
+
+static void xmit_free(XmitDetails *d);
+
+static int filemon_init(void);
+static void filemon_setfile(int mainfeed_fd, const char *mainfeed_path);
+static void filemon_callback(void);
+
+static void statemc_setstate(StateMachineState newsms, int periods,
+			     const char *forlog, const char *why);
+static void check_master_queue(void);
+static void queue_check_input_done(void);
+
+static void postfork(const char *what);
+static void postfork_inputfile(InputFile *ipf);
 
 /*----- configuration options -----*/
 
 static char *sitename, *feedfile;
 static const char *remote_host;
-static int quiet_multiple=0;
+static int quiet_multiple=0, become_daemon=1;
 
 static int max_connections=10, max_queue_per_conn=200;
 
@@ -179,28 +292,6 @@ static double nocheck_decay; /* computed in main from _articles */
 static int nocheck, nocheck_reported;
 
 
-/*----- doubly linked lists -----*/
-
-#define ISNODE(T)    T *next, *back;
-#define LIST(T)      struct { T *head, *tail, *tailpred; int count; }
-
-#define NODE(n) ((struct node*)&(n)->head)
-
-#define LIST_ADDHEAD(l,n)						\
- (list_addhead((struct list*)&(l), NODE((n))), (void)(l).count++)
-#define LIST_ADDTAIL(l,n)						\
- (list_addtail((struct list*)&(l), NODE((n))), (void)(l).count++)
-
-#define LIST_REMHEAD(l)							  \
- ((l).count ? ((l).count--, (void*)list_remhead((struct list*)&(l))) : 0)
-#define LIST_REMTAIL(l)							  \
- ((l).count ? ((l).count--, (void*)list_remtail((struct list*)&(l))) : 0)
-#define LIST_REMOVE(l,n)			\
- (list_remove(NODE((n))), (void)(l).count--)
-#define LIST_INSERT(l,n,pred) \
- (list_insert((struct list*)&(l), NODE((n)), NODE((pred))), (void)(l).count++)
-
-
 /*----- statistics -----*/
 
 typedef enum {      /* in queue                 in conn->sent             */
@@ -220,7 +311,7 @@ typedef enum {      /* in queue                 in conn->sent             */
 
 #define RCI_TRIPLE_FMT_BASE "%d(id%d+bd%d+nc%d)"
 #define RCI_TRIPLE_VALS_BASE(counts,x)		\
-       , counts[art_Unchecked] x		\
+       counts[art_Unchecked] x			\
        + counts[art_Wanted] x			\
        + counts[art_Unsolicited] x,		\
        counts[art_Unchecked] x			\
@@ -228,7 +319,7 @@ typedef enum {      /* in queue                 in conn->sent             */
        , counts[art_Unsolicited] x
 
 typedef enum {
-#define RC_INDEX(x) RCI_##x
+#define RC_INDEX(x) RC_##x,
   RESULT_COUNTS(RC_INDEX, RC_INDEX)
   RCI_max
 } ResultCountIndex;
@@ -239,32 +330,22 @@ typedef enum {
 #define CONNIOVS 128
 
 typedef enum {
-  xk_Malloc, xk_Const, xk_Artdata;
+  xk_Malloc, xk_Const, xk_Artdata
 } XmitKind;
 
-typedef struct {
+struct XmitDetails {
   XmitKind kind;
   union {
     char *malloc_tofree;
     ARTHANDLE *sm_art;
   } info;
-} XmitDetails;
+};
 
 
 /*----- core operational data structure types -----*/
 
-struct Article {
-  ArtState state;
-  int midlen;
-  InputFile *ipf;
-  TOKEN token;
-  off_t offset;
-  int blanklen;
-  char messageid[1];
-};
-
-typedef struct InputFile {
-  /* This is an instance of struct oop_readable */
+struct InputFile {
+  /* This is also an instance of struct oop_readable */
   struct oop_readable readable; /* first */
   oop_readable_call *readable_callback;
   void *readable_callback_user;
@@ -278,7 +359,18 @@ typedef struct InputFile {
 
   int counts[art_MaxState][RCI_max];
   char path[];
-} InputFile;
+};
+
+struct Article {
+  ISNODE(Article);
+  ArtState state;
+  int midlen;
+  InputFile *ipf;
+  TOKEN token;
+  off_t offset;
+  int blanklen;
+  char messageid[1];
+};
 
 #define SMS_LIST(X)				\
   X(NORMAL)					\
@@ -288,10 +380,10 @@ typedef struct InputFile {
   X(DROPPING)					\
   X(DROPPED)
 
-typedef enum {
+enum StateMachineState {
 #define SMS_DEF_ENUM(s) sm_##s,
   SMS_LIST(SMS_DEF_ENUM)
-} StateMachineState;
+};
 
 static const char *sms_names[]= {
 #define SMS_DEF_NAME(s) #s ,
@@ -301,9 +393,10 @@ static const char *sms_names[]= {
 
 struct Conn {
   ISNODE(Conn);
-  int fd, max_queue, stream;
-  LIST(Article) queue; /* not yet told peer, or CHECK said send it */
-  LIST(Article) sent; /* offered/transmitted - in xmit or waiting reply */
+  int fd, max_queue, stream, quitting;
+  ArticleList waiting; /* not yet told peer */
+  ArticleList priority; /* peer says send it now */
+  ArticleList sent; /* offered/transmitted - in xmit or waiting reply */
   struct iovec xmit[CONNIOVS];
   XmitDetails xmitd[CONNIOVS];
   int xmitu;
@@ -312,9 +405,11 @@ struct Conn {
 
 /*----- operational variables -----*/
 
-static int nconns;
-static LIST(Conn) idle, working, full;
-static LIST(Article) *queue;
+static oop_source *loop;
+
+static int until_connect;
+static ConnList conns;
+static ArticleList queue;
 
 static char *path_lock, *path_flushing, *path_defer;
 
@@ -327,19 +422,83 @@ static InputFile *main_input_file, *flushing_input_file, *backlog_input_file;
 static int sm_period_counter;
 
 
-/*----- function predeclarations -----*/
+/*========== logging ==========*/
+
+static void logcore(int sysloglevel, const char *fmt, ...)
+     __attribute__((__format__(printf,2,3)));
+static void logcore(int sysloglevel, const char *fmt, ...) {
+  va_list al;
+  va_start(al,fmt);
+  if (become_daemon) {
+    vsyslog(sysloglevel,fmt,al);
+  } else {
+    vfprintf(stderr,fmt,al);
+    putc('\n',stderr);
+  }
+  va_end(al);
+}
 
-static void conn_check_work(Conn *conn);
+static void logv(int sysloglevel, const char *pfx, int errnoval,
+		 int exitstatus, const char *fmt, va_list al)
+     __attribute__((__format__(printf,5,0)));
+static void logv(int sysloglevel, const char *pfx, int errnoval,
+		 int exitstatus, const char *fmt, va_list al) {
+  char msgbuf[256]; /* NB do not call xvasprintf here or you'll recurse */
+  vsnprintf(msgbuf,sizeof(msgbuf), fmt,al);
+  msgbuf[sizeof(msgbuf)-1]= 0;
 
-static int filemon_init(void);
-static void filemon_setfile(int mainfeed_fd, const char *mainfeed_path);
-static void filemon_callback(void);
+  if (sysloglevel >= LOG_ERR && (errnoval==EACCES || errnoval==EPERM))
+    sysloglevel= LOG_ERR; /* run by wrong user, probably */
+
+  logcore(sysloglevel, "<%s>%s: %s%s%s",
+	 sitename, pfx, msgbuf,
+	 errnoval>=0 ? ": " : "",
+	 errnoval>=0 ? strerror(errnoval) : "");
+}
+
+#define logwrap(fn, pfx, sysloglevel, err, estatus)	\
+  static void fn(const char *fmt, ...)			\
+      __attribute__((__format__(printf,1,2)));		\
+  static void fn(const char *fmt, ...) {		\
+    va_list al;						\
+    va_start(al,fmt);					\
+    logv(sysloglevel, pfx, err, estatus, fmt, al);	\
+  }
+
+logwrap(sysdie,   " critical", LOG_CRIT,    errno, 16);
+logwrap(die,      " critical", LOG_CRIT,    -1,    16);
+
+logwrap(sysfatal, " fatal",    LOG_ERR,     errno, 12);
+logwrap(fatal,    " fatal",    LOG_ERR,     -1,    12);
+
+logwrap(syswarn,  " warning",  LOG_WARNING, errno, 0);
+logwrap(warn,     " warning",  LOG_WARNING, -1,    0);
+
+logwrap(notice,   "",          LOG_NOTICE,  -1,    0);
+logwrap(info,     " info",     LOG_INFO,    -1,    0);
+logwrap(debug,    " debug",    LOG_DEBUG,   -1,    0);
 
-static void statemc_setstate(StateMachineState newsms, int periods,
-			     const char *forlog, const char *why);
 
 /*========== utility functions etc. ==========*/
 
+static char *xvasprintf(const char *fmt, va_list al)
+     __attribute__((__format__(printf,1,0)));
+static char *xvasprintf(const char *fmt, va_list al) {
+  char *str;
+  int rc= vasprintf(&str,fmt,al);
+  if (rc<0) sysdie("vasprintf(\"%s\",...) failed", fmt);
+  return str;
+}
+static char *xasprintf(const char *fmt, ...)
+     __attribute__((__format__(printf,1,2)));
+static char *xasprintf(const char *fmt, ...) {
+  va_list al;
+  va_start(al,fmt);
+  char *str= xvasprintf(fmt,al);
+  va_end(al);
+  return str;
+}
+
 static void perhaps_close(int *fd) { if (*fd) { close(*fd); fd=0; } }
 
 static pid_t xfork(const char *what) {
@@ -383,7 +542,7 @@ static void report_child_status(const char *what, int status) {
 static int xwaitpid(pid_t *pid, const char *what) {
   int status;
 
-  r= kill(*pid, SIGKILL);
+  int r= kill(*pid, SIGKILL);
   if (r) sysdie("cannot kill %s child", what);
 
   pid_t got= waitpid(*pid, &status, WNOHANG);
@@ -407,17 +566,18 @@ static void check_isreg(const struct stat *stab, const char *path,
 }
 
 static void xfstat(int fd, struct stat *stab_r, const char *what) {
-  int r= fstab(path, stab);
-  if (r) sysdie("could not fstat %s %s", what, path);
+  int r= fstat(fd, stab_r);
+  if (r) sysdie("could not fstat %s", what);
 }
 
-static void xfstat_isreg(int fd, struct stat *stab_r, const char *what) {
+static void xfstat_isreg(int fd, struct stat *stab_r,
+			 const char *path, const char *what) {
   xfstat(fd, stab_r, what);
-  check_isreg(stab, path, what);
+  check_isreg(stab_r, path, what);
 }
 
 static void xlstat_isreg(const char *path, struct stat *stab,
-			 int *enoent_r /* 0 means ENOENT is fatal */
+			 int *enoent_r /* 0 means ENOENT is fatal */,
 			 const char *what) {
   int r= lstat(path, stab);
   if (r) {
@@ -428,6 +588,13 @@ static void xlstat_isreg(const char *path, struct stat *stab,
   check_isreg(stab, path, what);
 }
 
+static void setnonblock(int fd, int nonblocking) {
+  int r= fcntl(fd, F_GETFL);  if (r<0) sysdie("setnonblocking fcntl F_GETFL");
+  if (nonblocking) r |= O_NONBLOCK;
+  else r &= ~O_NONBLOCK;
+  r= fcntl(fd, F_SETFL, r);  if (r<0) sysdie("setnonblocking fcntl F_SETFL");
+}
+
 static int samefile(const struct stat *a, const struct stat *b) {
   assert(S_ISREG(a->st_mode));
   assert(S_ISREG(b->st_mode));
@@ -435,77 +602,44 @@ static int samefile(const struct stat *a, const struct stat *b) {
 	  a->st_dev == b->st_dev);
 }
 
-/*========== logging ==========*/
+static char *sanitise(const char *input) {
+  static char sanibuf[100]; /* returns pointer to this buffer! */
 
-static void logcore(int sysloglevel, const char *fmt, ...)
-     __attribute__((printf,2,3))
-static void logcore(int sysloglevel, const char *fmt, ...) {
-  va_list al;
-  va_start(al,fmt);
-  if (become_daemon) {
-    vsyslog(sysloglevel,fmt,al);
-  } else {
-    vfprintf(stderr,fmt,al);
-    putc('\n',stderr);
+  const char *p= input;
+  char *q= sanibuf;
+  *q++= '`';
+  for (;;) {
+    if (q > sanibuf+sizeof(sanibuf)-8) { strcpy(q,"'.."); break; }
+    int c= *p++;
+    if (!c) { *q++= '\''; *q=0; break; }
+    if (c>=' ' && c<=126 && c!='\\') { *q++= c; continue; }
+    sprintf(q,"\\x%02x",c);
+    q += 4;
   }
-  va_end(al);
+  return sanibuf;
 }
 
-static void logv(int sysloglevel, const char *pfx, int errnoval,
-		 int exitstatus, const char *fmt, va_list al)
-     __attribute__((printf,4,0))
-static void logv(int sysloglevel, const char *pfx, int errnoval,
-		 int exitstatus, const char *fmt, va_list al) {
-  char msgbuf[256];
-  vsnprintf(msgbuf,sizeof(msgbuf), fmt,al);
-  msgbuf[sizeof(msgbuf)-1]= 0;
-
-  if (sysloglevel >= LOG_ERR && (errnoval==EACCES || errnoval==EPERM))
-    sysloglevel= LOG_ERR; /* run by wrong user, probably */
+/*========== making new connections ==========*/
 
-  logcore(sysloglevel, "<%s>%s: %s%s%s",
-	 sitename, pfx, msgbuf,
-	 errnoval>=0 ? ": " : "",
-	 errnoval>=0 ? strerror(errnoval) : "");
+static void conn_dispose(Conn *conn) {
+  if (!conn) return;
+  perhaps_close(&conn->fd);
+  free(conn);
+  until_connect= reconnect_delay_periods;
 }
 
-#define logwrap(fn, pfx, sysloglevel, errno, estatus)	\
-  static void fn(const char *fmt, ...)			\
-      __attribute__((printf,1,2));			\
-  static void fn(const char *fmt, ...) {		\
-    va_list al;						\
-    va_start(al,fmt);					\
-    logv(sysloglevel, pfx, errno, estatus, fmt, al);	\
-  }
-
-logwrap(sysdie,   " critical", LOG_CRIT,   errno, 16);
-logwrap(die,      " critical", LOG_CRIT,   -1,    16);
-
-logwrap(sysfatal, " fatal",    LOG_ERR,    errno, 12);
-logwrap(fatal,    " fatal",    LOG_ERR,    -1,    12);
-
-logwrap(syswarn,  " warning",  LOG_WARN,   errno, 0);
-logwrap(warn,     " warning",  LOG_WARN,   -1,    0);
-
-logwrap(notice,   "",          LOG_NOTICE, -1,    0);
-logwrap(info,     " info",     LOG_INFO,   -1,    0);
-logwrap(debug,    " debug",    LOG_DEBUG,  -1,    0);
-
-
-/*========== making new connections ==========*/
-
 static int connecting_sockets[2]= {-1,-1};
 static pid_t connecting_child;
 
 static void connect_attempt_discard(void) {
   if (connecting_sockets[0])
-    cancel_fd(connecting_sockets[0]);
+    cancel_fd_read_except(connecting_sockets[0]);
 
   perhaps_close(&connecting_sockets[0]);
   perhaps_close(&connecting_sockets[1]);
 
   if (connecting_child) {
-    r= kill(connecting_child, SIGTERM);
+    int r= kill(connecting_child, SIGTERM);
     if (r) syswarn("failed to kill connecting child");
     int status= xwaitpid(&connecting_child, "connect");
 
@@ -528,7 +662,7 @@ static void *connchild_event(oop_source *lp, int fd, oop_event e, void *u) {
   conn= xmalloc(sizeof(*conn));
   memset(conn,0,sizeof(*conn));
 
-  DECL_MSG_CMSG(msg);
+  PREP_DECL_MSG_CMSG(msg);
   struct cmsghdr *h= 0;
   ssize_t rs= recvmsg(fd, &msg, MSG_DONTWAIT);
   if (rs >= 0) h= CMSG_FIRSTHDR(&msg);
@@ -539,11 +673,11 @@ static void *connchild_event(oop_source *lp, int fd, oop_event e, void *u) {
       assert(got==connecting_child);
       connecting_child= 0;
       if (WIFEXITED(status) &&
-	  (WEXITSTATUS(status) != 0
+	  (WEXITSTATUS(status) != 0 &&
 	   WEXITSTATUS(status) != CONNCHILD_ESTATUS_STREAM &&
 	   WEXITSTATUS(status) != CONNCHILD_ESTATUS_NOSTREAM)) {
 	/* child already reported the problem */
-      } else if (WIFSIGNALED(status) && WTERMSIG(status) == SIGALARM) {
+      } else if (WIFSIGNALED(status) && WTERMSIG(status) == SIGALRM) {
 	warn("connect: connection attempt timed out");
       } else if (!WIFEXITED(status)) {
 	report_child_status("connect", status);
@@ -553,7 +687,7 @@ static void *connchild_event(oop_source *lp, int fd, oop_event e, void *u) {
       /* child is still running apparently, report the socket problem */
       if (rs < 0)
 	syswarn("connect: read from child socket failed");
-      else if (e == OOP_EXCEPTIONN)
+      else if (e == OOP_EXCEPTION)
 	warn("connect: unexpected exception on child socket");
       else
 	warn("connect: unexpected EOF on child socket");
@@ -568,13 +702,14 @@ static void *connchild_event(oop_source *lp, int fd, oop_event e, void *u) {
   }
   CHK(level, SOL_SOCKET);
   CHK(type,  SCM_RIGHTS);
-  CHK(len,   CMSG_LEN(sizeof(conn-b>fd)));
+  CHK(len,   CMSG_LEN(sizeof(conn->fd)));
 #undef CHK
 
-  if (CMSG_NXTHDR,&msg,h) { die("connect: child sent many cmsgs"); goto x; }
+  if (CMSG_NXTHDR(&msg,h)) { die("connect: child sent many cmsgs"); goto x; }
 
   memcpy(&conn->fd, CMSG_DATA(h), sizeof(conn->fd));
 
+  int status;
   pid_t got= waitpid(connecting_child, &status, 0);
   if (got==-1) sysdie("connect: real wait for child");
   assert(got == connecting_child);
@@ -589,23 +724,26 @@ static void *connchild_event(oop_source *lp, int fd, oop_event e, void *u) {
     fatal("connect: child gave unexpected exit status %d", es);
   }
 
-  set nonblocking;
-
   /* Phew! */
-  LIST_ADDHEAD(idle, conn);
+  setnonblock(conn->fd, 1);
+  conn->max_queue= conn->stream ? max_queue_per_conn : 1;
+  LIST_ADDHEAD(conns, conn);
   notice("#%d connected %s", conn->fd, conn->stream ? "streaming" : "plain");
   connect_attempt_discard();
   check_master_queue();
   return 0;
 
  x:
-  if (conn) {
-    perhaps_close(&conn->fd);
-    free(conn);
-  }
+  conn_dispose(conn);
   connect_attempt_discard();
 }
 
+static int allow_connect_start(void) {
+  return conns.count < max_connections
+    && !connecting_child
+    && !until_connect;
+}
+
 static void connect_start(void) {
   assert(!connecting_sockets[0]);
   assert(!connecting_sockets[1]);
@@ -613,7 +751,7 @@ static void connect_start(void) {
 
   notice("starting connection attempt");
 
-  r= socketpair(AF_UNIX, SOCK_STREAM, 0, connecting_sockets);
+  int r= socketpair(AF_UNIX, SOCK_STREAM, 0, connecting_sockets);
   if (r) { syswarn("connect: cannot create socketpair for child"); goto x; }
 
   connecting_child= xfork("connection");
@@ -627,15 +765,11 @@ static void connect_start(void) {
     if (r) sysdie("connect: close parent socket in child");
 
     alarm(connection_setup_timeout);
-    if (NNTPconnect(remote_host, port, &cn_from, &cn_to, buf) < 0) {
-      if (buf[0]) {
-	sanitise_inplace(buf);
-	fatal("connect: rejected: %s", buf);
-      } else {
-	sysfatal("connect: connection attempt failed");
-      }
+    if (NNTPconnect((char*)remote_host, port, &cn_from, &cn_to, buf) < 0) {
+      if (buf[0]) fatal("connect: rejected: %s", sanitise(buf));
+      else sysfatal("connect: connection attempt failed");
     }
-    if (NNTPsendpassword(remote_host, cn_from, cn_to) < 0)
+    if (NNTPsendpassword((char*)remote_host, cn_from, cn_to) < 0)
       sysfatal("connect: authentication failed");
     if (try_stream) {
       if (fputs("MODE STREAM\r\n", cn_to) ||
@@ -650,19 +784,16 @@ static void connect_start(void) {
       }
       int l= strlen(buf);
       assert(l>=1);
-      if (buf[-1]!='\n') {
-	sanitise_inplace(buf);
+      if (buf[-1]!='\n')
 	fatal("connect: response to MODE STREAM is too long: %.100s...",
-	    remote_host, buf);
-      }
-      l--;  if (l>0 && buf[1-]=='\r') l--;
+	    remote_host, sanitise(buf));
+      l--;  if (l>0 && buf[l-1]=='\r') l--;
       buf[l]= 0;
       char *ep;
       int rcode= strtoul(buf,&ep,10);
-      if (ep != buf[3]) {
-	sanitise_inplace(buf);
-	fatal("connect: bad response to MODE STREAM: %.50s", buf);
-      }
+      if (ep != &buf[3])
+	fatal("connect: bad response to MODE STREAM: %.50s", sanitise(buf));
+
       switch (rcode) {
       case 203:
 	exitstatus= CONNCHILD_ESTATUS_STREAM;
@@ -671,8 +802,8 @@ static void connect_start(void) {
       case 500:
 	break;
       default:
-	sanitise_inplace(buf);
-	warn("connect: unexpected response to MODE STREAM: %.50s", buf);
+	warn("connect: unexpected response to MODE STREAM: %.50s",
+	     sanitise(buf));
 	exitstatus= 2;
 	break;
       }
@@ -697,7 +828,7 @@ static void connect_start(void) {
   if (r) sysdie("connect: close child socket in parent");
 
   on_fd_read_except(connecting_sockets[0], connchild_event);
-  return OOP_CONTINUE;
+  return;
 
  x:
   connect_attempt_discard();
@@ -707,61 +838,51 @@ static void connect_start(void) {
 /*========== overall control of article flow ==========*/
 
 static void check_master_queue(void) {
-  if (!queue.count)
-    return;
-
-  Conn *last_assigned=0;
   for (;;) {
-    if (working.head) {
-      conn_assign_one_article(&working, &last_assigned);
-    } else if (idle.head) {
-      conn_assign_one_article(&idle, &last_assigned);
-    } else if (nconns < maxconns && queue.count >= max_queue_per_conn &&
-	       !connecting_child && !connect_delay) {
-      connect_delay= reconnect_delay_periods;
+    if (!queue.count)
+      break;
+    
+    Conn *walk, *use=0;
+    int spare;
+
+    /* Find a connection to offer this article.  We prefer a busy
+     * connection to an idle one, provided it's not full.  We take the
+     * first (oldest) and since that's stable, it will mean we fill up
+     * connections in order.  That way if we have too many
+     * connections, the spare ones will go away eventually.
+     */
+    for (walk=LIST_HEAD(conns); walk; walk=LIST_NEXT(walk)) {
+      int inqueue= walk->sent.count + walk->priority.count
+	         + walk->waiting.count;
+      spare= walk->max_queue - inqueue;
+      assert(inqueue <= max_queue_per_conn);
+      assert(spare >= 0);
+      if (inqueue==0) /*idle*/ { if (!use) use= walk; }
+      else if (spare>0) /*working*/ { use= walk; break; }
+    }
+    if (use) {
+      while (spare>0) {
+	Article *art= LIST_REMHEAD(queue);
+	LIST_ADDTAIL(use->waiting, art);
+	spare--;
+      }
+      conn_maybe_write(use);
+    } else if (allow_connect_start()) {
+      until_connect= reconnect_delay_periods;
       connect_start();
+      break;
     } else {
       break;
     }
   }
-  conn_check_work(last_assigned);
-}
-
-static void conn_assign_one_article(LIST(Conn) *connlist,
-				    Conn **last_assigned) {
-  Conn *conn= connlist->head;
-
-  LIST_REMOVE(*connlist, conn);
-  Article *art= LIST_REMHEAD(queue);
-  LIST_ADDTAIL(conn->queue, art);
-  LIST_ADD(*conn_determine_right_list(conn), conn);
-
-  /* This slightly odd arrangement is so that we call conn_check_work
-   * once after filling the queue for a new connection in
-   * check_master_queue, rather than for each article. */
-  if (conn != *last_assigned && *last_assigned)
-    conn_check_work(*last_assigned);
-  *last_assigned= conn;
-}
-
-static int conn_total_queued_articles(Conn *conn) {
-  return conn->sent.count + conn->queue.count;
 }
 
-static LIST(Conn) *conn_determine_right_list(Conn *conn) {
-  int inqueue= conn_total_queued_articles(conn);
-  assert(inqueue <= max_queue);
-  if (inqueue == 0) return &idle;
-  if (inqueue == conn->max_queue) return &full;
-  return &working;
-}
-
-static void *conn_writeable(oop_source *l, int fd, int ev, void *u) {
-  check_conn_work(u);
+static void *conn_writeable(oop_source *l, int fd, oop_event ev, void *u) {
+  conn_maybe_write(u);
   return OOP_CONTINUE;
 }
 
-static void conn_check_work(Conn *conn)  {
+static void conn_maybe_write(Conn *conn)  {
   void *rp= 0;
   for (;;) {
     conn_make_some_xmits(conn);
@@ -785,42 +906,41 @@ static void conn_check_work(Conn *conn)  {
 }
 
 static void vconnfail(Conn *conn, const char *fmt, va_list al)
-     __attribute__((printf,2,0));
+     __attribute__((__format__(printf,2,0)));
 
 static void vconnfail(Conn *conn, const char *fmt, va_list al) {
   int requeue[art_MaxState];
 
   Article *art;
-  while ((art= LIST_REMHEAD(conn->queue))) LIST_ADDTAIL(queue);
+  while ((art= LIST_REMHEAD(conn->priority))) LIST_ADDTAIL(queue, art);
+  while ((art= LIST_REMHEAD(conn->waiting))) LIST_ADDTAIL(queue, art);
   while ((art= LIST_REMHEAD(conn->sent))) {
-    counts[art->state]++;
+    requeue[art->state]++;
     if (art->state==art_Unsolicited) art->state= art_Unchecked;
-    LIST_ADDTAIL(queue);
+    LIST_ADDTAIL(queue,art);
   }
 
   int i;
-  XmitDetails *xd;
-  for (i=0, dp=&conn->xmitd; i<conn->xmitu; i++, dp++)
-    xmit_free(dp);
+  XmitDetails *d;
+  for (i=0, d=conn->xmitd; i<conn->xmitu; i++, d++)
+    xmit_free(d);
 
   char *m= xvasprintf(fmt,al);
   warn("#%d connection failed, requeueing " RCI_TRIPLE_FMT_BASE ": %s",
-       conn->fd, RCI_TRIPLE_FMT_VALS(requeue, /*nothing*/), m);
+       conn->fd, RCI_TRIPLE_VALS_BASE(requeue, /*nothing*/), m);
   free(m);
 
-  close(conn->fd);
-  free(conn);
-
-  connect_delay= reconnect_delay_periods;
+  LIST_REMOVE(conns,conn);
+  conn_dispose(conn);
   check_master_queue();
 }
 
-static void connfail(Connection *conn, const char *fmt, ...)
-     __attribute__((printf,2,3));
-static void connfail(Connection *conn, const char *fmt, ...) {
+static void connfail(Conn *conn, const char *fmt, ...)
+     __attribute__((__format__(printf,2,3)));
+static void connfail(Conn *conn, const char *fmt, ...) {
   va_list al;
   va_start(al,fmt);
-  vconnfail(fmt,al);
+  vconnfail(conn,fmt,al);
   va_end(al);
 }
 
@@ -830,7 +950,7 @@ static XmitDetails *xmit_core(Conn *conn, const char *data, int len,
                   XmitKind kind) { /* caller must then fill in details */
   struct iovec *v= &conn->xmit[conn->xmitu];
   XmitDetails *d= &conn->xmitd[conn->xmitu++];
-  v->iov_base= data;
+  v->iov_base= (char*)data;
   v->iov_len= len;
   d->kind= kind;
   return d;
@@ -842,7 +962,7 @@ static void xmit_noalloc(Conn *conn, const char *data, int len) {
 #define XMIT_LITERAL(lit) (xmit_noalloc(conn, (lit), sizeof(lit)-1))
 
 static void xmit_artbody(Conn *conn, ARTHANDLE *ah /* consumed */) {
-  XmitDetails *d= xmit_core(conn, ah->data, ah->len, sk_Artdata);
+  XmitDetails *d= xmit_core(conn, ah->data, ah->len, xk_Artdata);
   d->info.sm_art= ah;
 }
 
@@ -874,7 +994,8 @@ static void *conn_write_some_xmits(Conn *conn) {
     }
     assert(rs > 0);
 
-    for (done=0; rs && done<xmitu; done++) {
+    int done;
+    for (done=0; rs && done<conn->xmitu; done++) {
       struct iovec *vp= &conn->xmit[done];
       XmitDetails *dp= &conn->xmitd[done];
       if (rs > vp->iov_len) {
@@ -897,18 +1018,19 @@ static void conn_make_some_xmits(Conn *conn) {
     if (conn->xmitu+5 > CONNIOVS)
       break;
 
-    Article *art= LIST_REMHEAD(queue);
+    Article *art= LIST_REMHEAD(priority);
+    if (!art) art= LIST_REMHEAD(waiting);
     if (!art) break;
 
     if (art->state >= art_Wanted || (conn->stream && nocheck)) {
       /* actually send it */
 
-      ARTHANDLE *artdata= SMretrieve();
+      ARTHANDLE *artdata= SMretrieve(art->token, RETR_ALL);
 
       if (conn->stream) {
 	if (artdata) {
 	  XMIT_LITERAL("TAKETHIS ");
-	  xmit_noalloc(conn, art->mid, art->midlen);
+	  xmit_noalloc(conn, art->messageid, art->midlen);
 	  XMIT_LITERAL("\r\n");
 	  xmit_artbody(conn, artdata);
 	}
@@ -924,8 +1046,8 @@ static void conn_make_some_xmits(Conn *conn) {
       art->state=
 	art->state == art_Unchecked ? art_Unsolicited :
 	art->state == art_Wanted    ? art_Wanted      :
-	abort();
-      art->ipf->counts[art->state].sent++;
+	(abort(),-1);
+      art->ipf->counts[art->state][RC_sent]++;
       LIST_ADDTAIL(conn->sent, art);
 
     } else {
@@ -935,11 +1057,11 @@ static void conn_make_some_xmits(Conn *conn) {
 	XMIT_LITERAL("IHAVE ");
       else
 	XMIT_LITERAL("CHECK ");
-      xmit_noalloc(art->mid, art->midlen);
+      xmit_noalloc(conn, art->messageid, art->midlen);
       XMIT_LITERAL("\r\n");
 
       assert(art->state == art_Unchecked);
-      art->ipf->counts[art->state].sent++;
+      art->ipf->counts[art->state][RCI_sent]++;
       LIST_ADDTAIL(conn->sent, art);
     }
   }
@@ -962,12 +1084,12 @@ static void *peer_rd_err(oop_source *lp, oop_read *oread, oop_event ev,
   return OOP_CONTINUE;
 }
 
-static Article *article_reply_check(Connection *conn, const char *response,
+static Article *article_reply_check(Conn *conn, const char *response,
 				    int code_indicates_streaming,
 				    int must_have_sent
 				        /* 1:yes, -1:no, 0:dontcare */,
 				    const char *sanitised_response) {
-  Article *art= conn->sent.head;
+  Article *art= LIST_HEAD(conn->sent);
 
   if (!art) {
     connfail(conn,
@@ -979,20 +1101,20 @@ static Article *article_reply_check(Connection *conn, const char *response,
   if (code_indicates_streaming) {
     assert(!memchr(response, 0, 4)); /* ensured by peer_rd_ok */
     if (!conn->stream) {
-      connfail("peer gave streaming response code "
+      connfail(conn, "peer gave streaming response code "
 	       " to IHAVE or subsequent body: %s", sanitised_response);
       return 0;
     }
     const char *got_mid= response+4;
     int got_midlen= strcspn(got_mid, " \n\r");
     if (got_midlen<3 || got_mid[0]!='<' || got_mid[got_midlen-1]!='>') {
-      connfail("peer gave streaming response with syntactically invalid"
+      connfail(conn, "peer gave streaming response with syntactically invalid"
 	       " messageid: %s", sanitised_response);
       return 0;
     }
     if (got_midlen != art->midlen ||
 	memcmp(got_mid, art->messageid, got_midlen)) {
-      connfail("peer gave streaming response code to wrong article -"
+      connfail(conn, "peer gave streaming response code to wrong article -"
 	       " probable synchronisation problem; we offered: %s;"
 	       " peer said: %s",
 	       art->messageid, sanitised_response);
@@ -1000,19 +1122,19 @@ static Article *article_reply_check(Connection *conn, const char *response,
     }
   } else {
     if (conn->stream) {
-      connfail("peer gave non-streaming response code to CHECK/TAKETHIS: %s",
-	       sanitised_response);
+      connfail(conn, "peer gave non-streaming response code to"
+	       " CHECK/TAKETHIS: %s", sanitised_response);
       return 0;
     }
   }
 
   if (must_have_sent>0 && art->state < art_Wanted) {
-    connfail("peer says article accepted but we had not sent the body: %s",
-	     sanitised_response);
+    connfail(conn, "peer says article accepted but"
+	     " we had not sent the body: %s", sanitised_response);
     return 0;
   }
   if (must_have_sent<0 && art->state >= art_Wanted) {
-    connfail("peer says please sent the article but we just did: %s",
+    connfail(conn, "peer says please sent the article but we just did: %s",
 	     sanitised_response);
     return 0;
   }
@@ -1023,8 +1145,8 @@ static Article *article_reply_check(Connection *conn, const char *response,
 }
 
 static void update_nocheck(int accepted) {
-  accept_proportion *= accept_decay;
-  accept_proportion += accepted;
+  accept_proportion *= nocheck_decay;
+  accept_proportion += accepted * (1.0 - nocheck_decay);
   int new_nocheck= accept_proportion >= nocheck_thresh;
   if (new_nocheck && !nocheck_reported) {
     notice("entering nocheck mode for the first time");
@@ -1035,7 +1157,7 @@ static void update_nocheck(int accepted) {
   nocheck= new_nocheck;
 }
 
-static void article_done(Connection *conn, Article *art, int whichcount) {
+static void article_done(Conn *conn, Article *art, int whichcount) {
   art->ipf->counts[art->state][whichcount]++;
   if (whichcount == RC_accepted) update_nocheck(1);
   else if (whichcount == RC_unwanted) update_nocheck(0);
@@ -1079,32 +1201,28 @@ static void *peer_rd_ok(oop_source *lp, oop_read *oread, oop_event ev,
   }
   assert(ev == OOP_RD_OK);
 
+  char *sani= sanitise(data);
+
   char *ep;
   unsigned long code= strtoul(data, &ep, 10);
   if (ep != data+3 || *ep != ' ' || data[0]=='0') {
-    char sanibuf[100];
-    const char *p= data;
-    char *q= sanibuf;
-    *q++= '`';
-    for (;;) {
-      if (q > sanibuf+sizeof(sanibuf)-8) { strcpy(q,"..."); break; }
-      int c= *p++;
-      if (!c) { *q++= '\''; break; }
-      if (c>=' ' && c<=126 && c!='\\') { *q++= c; continue; }
-      sprintf(q,"\\x%02x",c);
-      q += 4;
-    }
-    connfail(conn, "badly formatted response from peer: %s", sanibuf);
+    connfail(conn, "badly formatted response from peer: %s", sani);
     return OOP_CONTINUE;
   }
 
   if (conn->quitting) {
-    if (code!=205) {
-      connfail(conn, "peer gave failure response to QUIT: %s", sani);
-      return OOP_CONTINUE;
+    if (code!=205 && code!=503) {
+      connfail(conn, "peer gave unexpected response to QUIT: %s", sani);
+    } else {
+      notice("#%d idle connection closed\n");
+      assert(!conn->waiting.count);
+      assert(!conn->priority.count);
+      assert(!conn->sent.count);
+      assert(!conn->xmitu);
+      LIST_REMOVE(conns,conn);
+      conn_dispose(conn);
     }
-    conn close ok;
-    return;
+    return OOP_CONTINUE;
   }
 
   Article *art;
@@ -1114,7 +1232,7 @@ static void *peer_rd_ok(oop_source *lp, oop_read *oread, oop_event ev,
   if (art) ; else return OOP_CONTINUE /* reply_check has failed the conn */
 
 #define ARTICLE_DEALTWITH(streaming,musthavesent,how)		\
-  code_streaming= (streaming)					\
+  code_streaming= (streaming);					\
   GET_ARTICLE(musthavesent);					\
   article_done(conn, art, RC_##how);  break;
 
@@ -1142,9 +1260,9 @@ static void *peer_rd_ok(oop_source *lp, oop_read *oread, oop_event ev,
   case 335: /* IHAVE says send it */
     GET_ARTICLE(-1);
     assert(art->state == art_Unchecked);
-    art->ipf->counts[art->state].accepted++;
+    art->ipf->counts[art->state][RC_accepted]++;
     art->state= art_Wanted;
-    LIST_ADDTAIL(conn->queue);
+    LIST_ADDTAIL(conn->priority, art);
     break;
 
   case 431: /* CHECK or TAKETHIS says try later */
@@ -1160,7 +1278,8 @@ static void *peer_rd_ok(oop_source *lp, oop_read *oread, oop_event ev,
 
   }
 
-  check_check_work(conn);
+  conn_maybe_write(sendon);
+  check_master_queue();
   return OOP_CONTINUE;
 }
 
@@ -1716,7 +1835,7 @@ static void notice_processed(InputFile *ipf, const char *what,
 			     const char *spec) {
 #define RCI_NOTHING(x) /* nothing */
 #define RCI_TRIPLE_FMT(x) " " #x "=" RCI_TRIPLE_FMT_BASE
-#define RCI_TRIPLE_VALS(x) RCI_TRIPLE_VALS_BASE(ipf->counts, .x)
+#define RCI_TRIPLE_VALS(x) , RCI_TRIPLE_VALS_BASE(ipf->counts, .x)
 
   info("processed %s%s offered=%d(ch%d,nc%d) accepted=%d(ch%d+nc%d)"
        RESULT_COUNTS(RCI_NOTHING, RCI_TRIPLE_FMT)
@@ -2113,13 +2232,6 @@ static void postfork_inputfile(InputFile *ipf) {
   ipf->fd= -1;
 }
 
-static void postfork_conns(Connection *conn) {
-  while (conn) {
-    close(conn->fd);
-    conn= conn->next;
-  }
-}
-
 static void postfork_stdio(FILE *f) {
   /* we have no stdio streams that are buffered long-term */
   if (f) fclose(f);
@@ -2131,9 +2243,11 @@ static void postfork(const char *what) {
 
   postfork_inputfile(main_input_file);
   postfork_inputfile(flushing_input_file);
-  postfork_conns(idle.head);
-  postfork_conns(working.head);
-  postfork_conns(full.head);
+
+  Conn *conn;
+  for (conn=LIST_HEAD(conns); conn; conn=LIST_NEXT(conn))
+    close(conn->fd);
+
   postfork_stdio(defer);
 }
 
@@ -2165,18 +2279,17 @@ static const char *debug_ipf_path(InputFile *ipf) {
 
 EVERY(period, {PERIOD_SECONDS,0}, {
   debug("PERIOD"
-	" sms=%s[%d] queue=%d connect_delay=%d"
+	" sms=%s[%d] conns=%d queue=%d until_connect=%d"
 	" input_files" DEBUGF_IPF(main) DEBUGF_IPF(old) DEBUGF_FMT(flushing)
-	" conns idle=%d working=%d full=%d"
 	" children connecting=%ld inndcomm_child"
 	,
-	sms_names[sms], sm_period_counter, queue.count, connect_delay,
+	sms_names[sms], sm_period_counter,
+	queue.count, conns.count, until_connect,
 	DEBUG_IPF(main), DEBUG_IPF(flushing), DEBUG_IPF(flushing),
-	idle.count, working.count, full.count,
 	(long)connecting_child, (long)inndcomm_child
 	);
 
-  if (connect_delay) connect_delay--;
+  if (until_connect) until_connect--;
 
   poll_backlog_file();
   if (!backlog_input_file) close_defer(); /* want to start on a new backlog */
@@ -2370,6 +2483,9 @@ int main(int argc, char **argv) {
     if (strchr(feedfile, c))
       badusage("feed filename may not contain metacharacter %c",c);
 
+  loop= oop_sys_new();
+  if (!loop) sysdie("could not create liboop event loop");
+
   if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
     sysdie("could not ignore SIGPIPE");