15 files changed, 454 insertions, 9 deletions

diff --git a/src/include/skalibs/djbunix.h b/src/include/skalibs/djbunix.h
index b095c82..00d8f00 100644
--- a/src/include/skalibs/djbunix.h
+++ b/src/include/skalibs/djbunix.h
@@ -190,6 +190,8 @@ extern pid_t child_spawn2 (char const *, char const *const *, char const *const
     * if n>=2, parent reads on even and writes on odd.
  */
 
+#define SKALIBS_CHILD_SPAWN_FDS_ENVVAR "SKALIBS_CHILD_SPAWN_FDS"
+
 extern pid_t child_spawn (char const *, char const *const *, char const *const *, int *, unsigned int) ;
 
 #endif
diff --git a/src/include/skalibs/textclient.h b/src/include/skalibs/textclient.h
new file mode 100644
index 0000000..17d4fff
--- /dev/null
+++ b/src/include/skalibs/textclient.h
@@ -0,0 +1,112 @@
+/* ISC license. */
+
+#ifndef SKALIBS_TEXTCLIENT_H
+#define SKALIBS_TEXTCLIENT_H
+
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <stdint.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/tai.h>
+#include <skalibs/textmessage.h>
+
+
+ /*
+   This is a simpler, smaller version of skaclient for basic cases:
+   - no fd-passing
+   - no asyncout
+   - no kolbak: client calls are always synchronous
+   - fixed-size buffers included in the client structure
+ */
+
+#define TEXTCLIENT_BUFSIZE 4096
+#define TEXTCLIENT_OPTION_WAITPID 0x00000001U
+
+
+ /* Server-side functions */
+
+extern int textclient_server_init (textmessage_receiver_t *, textmessage_sender_t *, textmessage_sender_t *, char const *, size_t, char const *, size_t, tain_t const *, tain_t *) ;
+extern int textclient_server_init_frompipe (textmessage_receiver_t *, textmessage_sender_t *, textmessage_sender_t *, char const *, size_t, char const *, size_t, tain_t const *, tain_t *) ;
+extern int textclient_server_init_fromsocket (textmessage_receiver_t *, textmessage_sender_t *, textmessage_sender_t *, char const *, size_t, char const *, size_t, tain_t const *, tain_t *) ;
+#define textclient_server_init_g(in, syncout, asyncout, before, beforelen, after, afterlen, deadline) textclient_server_init(in, syncout, asyncout, before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_server_init_frompipe_g(in, syncout, asyncout, before, beforelen, after, afterlen, deadline) textclient_server_init_frompipe(in, syncout, asyncout, before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_server_init_fromsocket_g(in, syncout, asyncout, before, beforelen, after, afterlen, deadline) textclient_server_init_fromsocket(in, syncout, asyncout, before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_server_01x_init(before, beforelen, after, afterlen, deadline, stamp) textclient_server_init(textmessage_receiver_0, textmessage_sender_1, textmessage_sender_x, before, beforelen, after, afterlen, deadline, stamp)
+#define textclient_server_01x_init_frompipe(before, beforelen, after, afterlen, deadline, stamp) textclient_server_init_frompipe(textmessage_receiver_0, textmessage_sender_1, textmessage_sender_x, before, beforelen, after, afterlen, deadline, stamp)
+#define textclient_server_01x_init_fromsocket(before, beforelen, after, afterlen, deadline, stamp) textclient_server_init_fromsocket(textmessage_receiver_0, textmessage_sender_1, textmessage_sender_x, before, beforelen, after, afterlen, deadline, stamp)
+#define textclient_server_01x_init_g(before, beforelen, after, afterlen, deadline) textclient_server_01x_init(before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_server_01x_init_frompipe_g(before, beforelen, after, afterlen, deadline) textclient_server_01x_init_frompipe(before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_server_01x_init_fromsocket_g(before, beforelen, after, afterlen, deadline) textclient_server_01x_init_fromsocket(before, beforelen, after, afterlen, (deadline), &STAMP)
+
+
+ /* User structure */
+
+typedef struct textclient_s textclient_t, *textclient_t_ref ;
+struct textclient_s
+{
+  textmessage_sender_t syncout ;
+  textmessage_receiver_t syncin ;
+  textmessage_receiver_t asyncin ;
+  pid_t pid ;
+  uint32_t options ;
+  char syncbuf[TEXTCLIENT_BUFSIZE] ;
+  char asyncbuf[TEXTCLIENT_BUFSIZE] ;
+} ;
+#define TEXTCLIENT_ZERO { .syncout = TEXTMESSAGE_SENDER_ZERO, .syncin = TEXTMESSAGE_RECEIVER_ZERO, .asyncin = TEXTMESSAGE_RECEIVER_ZERO, .pid = 0, .options = 0 }
+extern textclient_t const textclient_zero ;
+
+
+ /* Starting and ending */
+
+extern void textclient_end (textclient_t *) ;
+
+extern int textclient_start (textclient_t *, char const *, uint32_t, char const *, size_t, char const *, size_t, tain_t const *, tain_t *) ;
+extern int textclient_startf (textclient_t *, char const *const *, char const *const *, uint32_t, char const *, size_t, char const *, size_t, tain_t const *, tain_t *) ;
+
+#define textclient_start_g(a, path, options, before, beforelen, after, afterlen, deadline) textclient_start(a, path, options, before, beforelen, after, afterlen, (deadline), &STAMP)
+#define textclient_startf_g(a, argv, envp, options, before, beforelen, after, afterlen, deadline) textclient_startf_b(a, argv, envp, options, before, beforelen, after, afterlen, (deadline), &STAMP)
+
+
+ /* Writing */
+
+#define textclient_put(a, s, len) textmessage_sender_put(&(a)->syncout, s, len)
+#define textclient_putv(a, v, n) textmessage_sender_putv(&(a)->syncout, v, n)
+#define textclient_flush(a) textmessage_sender_flush(&(a)->syncout)
+#define textclient_timed_flush(a, deadline, stamp) textmessage_sender_timed_flush(&(a)->syncout, deadline, stamp)
+#define textclient_timed_flush_g(a, deadline) textclient_timed_flush(a, (deadline), &STAMP)
+#define textclient_send(a, s, len) textmessage_send(&(a)->syncout, s, len)
+#define textclient_sendv(a, v, n) textmessage_sendv(&(a)->syncout, v, n)
+#define textclient_timed_send(a, s, len, deadline, stamp) textmessage_timed_send(&(a)->syncout, s, len, deadline, stamp)
+#define textclient_timed_sendv(a, v, n, deadline, stamp) textmessage_timed_sendv(&(a)->syncout, v, n, deadline, stamp)
+#define textclient_timed_send_g(a, s, len, deadline) textclient_timed_send(a, s, len, (deadline), &STAMP)
+#define textclient_timed_sendv_g(a, v, n, deadline) textclient_timed_sendv(a, v, n, (deadline), &STAMP)
+
+
+ /* Sync reading */
+
+#define textclient_get(a, v) textmessage_receive(&(a)->syncin, v)
+#define textclient_timed_get(a, v, deadline, stamp) (sanitize_read(textmessage_timed_receive(&(a)->syncin, v, deadline, stamp)) > 0)
+#define textclient_timed_get_g(a, v, deadline) textclient_timed_get(a, v, (deadline), &STAMP)
+
+
+ /* Sync writing+reading */
+
+#define textclient_exchange(a, s, len, ans, deadline, stamp) (textclient_timed_send(a, s, len, deadline, stamp) && textclient_timed_get(a, ans, deadline, stamp))
+#define textclient_exchangev(a, v, n, ans, deadline, stamp) (textclient_timed_sendv(a, v, n, deadline, stamp) && textclient_timed_get(a, ans, deadline, stamp))
+#define textclient_exchange_g(a, s, len, ans, deadline) textclient_exchange(a, s, len, ans, (deadline), &STAMP)
+#define textclient_exchangev_g(a, v, n, ans, deadline) textclient_exchangev(a, v, n, ans, (deadline), &STAMP)
+
+extern int textclient_command (textclient_t *, char const *, size_t, tain_t const *, tain_t *) ;
+extern int textclient_commandv (textclient_t *, struct iovec const *, unsigned int, tain_t const *, tain_t *) ;
+#define textclient_command_g(a, s, len, deadline) textclient_command(a, s, len, (deadline), &STAMP)
+#define textclient_commandv_g(a, v, n, deadline) textclient_commandv(a, v, n, (deadline), &STAMP)
+
+
+ /* Async reading */
+
+#define textclient_fd(a) textmessage_receiver_fd(&(a)->asyncin)
+#define textclient_update(a, f, p) textmessage_handle(&(a)->asyncin, f, p)
+#define textclient_timed_update(a, f, p, deadline, stamp) textmessage_timed_handle(&(a)->asyncin, f, p, deadline, stamp)
+#define textclient_timed_update_g(a, f, p, deadline) textclient_timed_update(a, f, p, (deadline), &STAMP)
+
+#endif
diff --git a/src/include/skalibs/textmessage.h b/src/include/skalibs/textmessage.h
index 9904534..fd393a9 100644
--- a/src/include/skalibs/textmessage.h
+++ b/src/include/skalibs/textmessage.h
@@ -13,6 +13,7 @@
 #include <skalibs/tai.h>
 
 #define TEXTMESSAGE_MAXREADS 128
+#define TEXTMESSAGE_MAXLEN 0x01000000U
 
 
  /* Sender */
@@ -36,13 +37,13 @@ extern int textmessage_put (textmessage_sender_t *, char const *, size_t) ;
 extern int textmessage_putv (textmessage_sender_t *, struct iovec const *, unsigned int) ;
 
 extern int textmessage_sender_flush (textmessage_sender_t *) ;
-extern int unixmessage_sender_timed_flush (textmessage_sender_t *, tain_t const *, tain_t *) ;
+extern int textmessage_sender_timed_flush (textmessage_sender_t *, tain_t const *, tain_t *) ;
 #define textmessage_sender_timed_flush_g(ts, deadline) textmessage_sender_timed_flush(ts, (deadline), &STAMP)
 
 #define textmessage_send(ts, s, len) (textmessage_put(ts, s, len) && textmessage_sender_flush(ts))
 #define textmessage_sendv(ts, v, n) (textmessage_putv(ts, v, n) && textmessage_sender_flush(ts))
-#define textmessage_timed_send(ts, s, len, deadline, stamp) (textmessage_put(ts, s, len) && texxtmessage_sender_timed_flush(ts, deadline, stamp))
-#define textmessage_timed_sendv(ts, v, n, deadline, stamp) (textmessage_putv(ts, v, n) && texxtmessage_sender_timed_flush(ts, deadline, stamp))
+#define textmessage_timed_send(ts, s, len, deadline, stamp) (textmessage_put(ts, s, len) && textmessage_sender_timed_flush(ts, deadline, stamp))
+#define textmessage_timed_sendv(ts, v, n, deadline, stamp) (textmessage_putv(ts, v, n) && textmessage_sender_timed_flush(ts, deadline, stamp))
 #define textmessage_timed_send_g(ts, s, len, deadline) textmessage_timed_send(ts, s, len, (deadline), &STAMP)
 #define textmessage_timed_sendv_g(ts, v, n, deadline) textmessage_timed_sendv(ts, v, n, (deadline), &STAMP)
 
@@ -71,14 +72,14 @@ extern int textmessage_receiver_hasmsginbuf (textmessage_receiver_t const *) gcc
 
 extern int textmessage_receive (textmessage_receiver_t *, struct iovec *) ;
 extern int textmessage_timed_receive (textmessage_receiver_t *, struct iovec *, tain_t const *, tain_t *) ;
-#define textmessage_timed_receive_g(tr, s, max, deadline) textmessage_timed_receive(tr, s, max, (deadline), &STAMP)
+#define textmessage_timed_receive_g(tr, v, deadline) textmessage_timed_receive(tr, v, (deadline), &STAMP)
 
 typedef int textmessage_handler_func_t (struct iovec const *, void *) ;
 typedef textmessage_handler_func_t *textmessage_handler_func_t_ref ;
 
 extern int textmessage_handle (textmessage_receiver_t *, textmessage_handler_func_t_ref, void *) ;
 extern int textmessage_timed_handle (textmessage_receiver_t *, textmessage_handler_func_t_ref, void *, tain_t const *, tain_t *) ;
-#define textmessage_timed_handle_g(tr, f, p, deadline) unixmessage_timed_handle(tr, f, p, (deadline), &STAMP)
+#define textmessage_timed_handle_g(tr, f, p, deadline) textmessage_timed_handle(tr, f, p, (deadline), &STAMP)
 
 
 
diff --git a/src/include/skalibs/unixonacid.h b/src/include/skalibs/unixonacid.h
index 43bd695..7132f1c 100644
--- a/src/include/skalibs/unixonacid.h
+++ b/src/include/skalibs/unixonacid.h
@@ -6,6 +6,7 @@
 #include <skalibs/unix-transactional.h>
 #include <skalibs/unix-timed.h>
 #include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
 #include <skalibs/unixmessage.h>
 #include <skalibs/unixconnection.h>
 #include <skalibs/kolbak.h>
diff --git a/src/libunixonacid/textclient_command.c b/src/libunixonacid/textclient_command.c
new file mode 100644
index 0000000..2e72a4c
--- /dev/null
+++ b/src/libunixonacid/textclient_command.c
@@ -0,0 +1,15 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/textclient.h>
+
+int textclient_command (textclient_t *a, char const *s, size_t len, tain_t const *deadline, tain_t *stamp)
+{
+  struct iovec ans ;
+  if (!textclient_exchange(a, s, len, &ans, deadline, stamp)) return 0 ;
+  if (ans.iov_len != 1) return (errno = EPROTO, 0) ;
+  if (*(char *)ans.iov_base) return (errno = *(char *)ans.iov_base, 0) ;
+  return 1 ;
+}
diff --git a/src/libunixonacid/textclient_commandv.c b/src/libunixonacid/textclient_commandv.c
new file mode 100644
index 0000000..5bcd411
--- /dev/null
+++ b/src/libunixonacid/textclient_commandv.c
@@ -0,0 +1,15 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/textclient.h>
+
+int textclient_commandv (textclient_t *a, struct iovec const *v, unsigned int n, tain_t const *deadline, tain_t *stamp)
+{
+  struct iovec ans ;
+  if (!textclient_exchangev(a, v, n, &ans, deadline, stamp)) return 0 ;
+  if (ans.iov_len != 1) return (errno = EPROTO, 0) ;
+  if (*(char *)ans.iov_base) return (errno = *(char *)ans.iov_base, 0) ;
+  return 1 ;
+}
diff --git a/src/libunixonacid/textclient_end.c b/src/libunixonacid/textclient_end.c
new file mode 100644
index 0000000..58fc930
--- /dev/null
+++ b/src/libunixonacid/textclient_end.c
@@ -0,0 +1,22 @@
+/* ISC license. */
+
+#include <skalibs/djbunix.h>
+#include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
+
+void textclient_end (textclient_t *a)
+{
+  fd_close(textmessage_sender_fd(&a->syncout)) ;
+  if (textmessage_receiver_fd(&a->syncin) != textmessage_sender_fd(&a->syncout))
+    fd_close(textmessage_receiver_fd(&a->syncin)) ;
+  fd_close(textmessage_receiver_fd(&a->asyncin)) ;
+  textmessage_sender_free(&a->syncout) ;
+  textmessage_receiver_free(&a->syncin) ;
+  textmessage_receiver_free(&a->asyncin) ;
+  if (a->pid && a->options & TEXTCLIENT_OPTION_WAITPID)
+  {
+    int wstat ;
+    waitpid_nointr(a->pid, &wstat, 0) ;
+  }
+  *a = textclient_zero ;
+}
diff --git a/src/libunixonacid/textclient_server_init.c b/src/libunixonacid/textclient_server_init.c
new file mode 100644
index 0000000..27d3a20
--- /dev/null
+++ b/src/libunixonacid/textclient_server_init.c
@@ -0,0 +1,12 @@
+/* ISC license. */
+
+#include <stdlib.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/textclient.h>
+
+int textclient_server_init (textmessage_receiver_t *in, textmessage_sender_t *syncout, textmessage_sender_t *asyncout, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
+{
+  return getenv(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ?
+    textclient_server_init_frompipe(in, syncout, asyncout, before, beforelen, after, afterlen, deadline, stamp) :
+    textclient_server_init_fromsocket(in, syncout, asyncout, before, beforelen, after, afterlen, deadline, stamp) ;
+}
diff --git a/src/libunixonacid/textclient_server_init_frompipe.c b/src/libunixonacid/textclient_server_init_frompipe.c
new file mode 100644
index 0000000..fb85b44
--- /dev/null
+++ b/src/libunixonacid/textclient_server_init_frompipe.c
@@ -0,0 +1,30 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <skalibs/types.h>
+#include <skalibs/error.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
+
+int textclient_server_init_frompipe (textmessage_receiver_t *in, textmessage_sender_t *syncout, textmessage_sender_t *asyncout, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
+{
+  struct iovec v ;
+  unsigned int asyncfd ;
+  char *x = getenv(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
+  if (!x
+   || !uint0_scan(x, &asyncfd)
+   || asyncfd == textmessage_sender_fd(syncout)
+   || asyncfd == textmessage_receiver_fd(in)) return (errno = EPROTO, 0) ;
+  if (sanitize_read(textmessage_timed_receive(in, &v, deadline, stamp)) <= 0) return 0 ;
+  if (v.iov_len != beforelen || memcmp(v.iov_base, before, beforelen)) return (errno = EPROTO, 0) ;
+  if (fcntl(asyncfd, F_GETFD) < 0) return 0 ;
+  if (!textmessage_timed_send(syncout, after, afterlen, deadline, stamp)) return 0 ;
+  textmessage_sender_init(asyncout, asyncfd) ;
+  if (!textmessage_timed_send(asyncout, after, afterlen, deadline, stamp)) return 0 ;
+  return 1 ;
+}
diff --git a/src/libunixonacid/textclient_server_init_fromsocket.c b/src/libunixonacid/textclient_server_init_fromsocket.c
new file mode 100644
index 0000000..5b71463
--- /dev/null
+++ b/src/libunixonacid/textclient_server_init_fromsocket.c
@@ -0,0 +1,86 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+#include <skalibs/nonposix.h>
+#include <sys/uio.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <skalibs/types.h>
+#include <skalibs/error.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-timed.h>
+#include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
+
+#ifndef MSG_NOSIGNAL
+#define MSG_NOSIGNAL 0
+#endif
+
+union aligner_u
+{
+  struct cmsghdr cmsghdr ;
+  int i ;
+} ;
+
+static int getfd (void *p)
+{
+  return ((int *)p)[0] ;
+}
+
+static int one (void *p)
+{
+  (void)p ;
+  return 1 ;
+}
+
+static int sendit (void *p)
+{
+  int *fd = p ;
+  union aligner_u ancilbuf[1 + (CMSG_SPACE(sizeof(int)) - 1) / sizeof(union aligner_u)] ;
+  ssize_t r ;
+  char ch = '|' ;
+  struct iovec v = { .iov_base = &ch, .iov_len = 1 } ;
+  struct msghdr hdr =
+  {
+    .msg_name = 0,
+    .msg_namelen = 0,
+    .msg_iov = &v,
+    .msg_iovlen = 1,
+    .msg_control = ancilbuf,
+    .msg_controllen = CMSG_SPACE(sizeof(int))
+  } ;
+  struct cmsghdr *c = CMSG_FIRSTHDR(&hdr) ;
+  memset(hdr.msg_control, 0, hdr.msg_controllen) ;
+  c->cmsg_level = SOL_SOCKET ;
+  c->cmsg_type = SCM_RIGHTS ;
+  c->cmsg_len = CMSG_LEN(sizeof(int)) ;
+  *(int *)CMSG_DATA(c) = fd[1] ;
+  do r = sendmsg(fd[0], &hdr, MSG_NOSIGNAL) ;
+  while (r < 0 && errno == EINTR) ;
+  if (r <= 0) return 0 ;
+#ifndef SKALIBS_HASANCILAUTOCLOSE
+  fd_close(fd[1]) ;
+#endif
+  return 1 ;
+}
+
+int textclient_server_init_fromsocket (textmessage_receiver_t *in, textmessage_sender_t *syncout, textmessage_sender_t *asyncout, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
+{
+  int fd[3] = { textmessage_sender_fd(syncout) } ;
+  struct iovec v ;
+  if (sanitize_read(textmessage_timed_receive(in, &v, deadline, stamp)) <= 0) return 0 ;
+  if (v.iov_len != beforelen || memcmp(v.iov_base, before, beforelen)) return (errno = EPROTO, 0) ;
+  if (pipenbcoe(fd+1) < 0) return 0 ;
+  if (!timed_flush(fd, &getfd, &one, &sendit, deadline, stamp)) goto err ;
+  if (!textmessage_timed_send(syncout, after, afterlen, deadline, stamp)) goto err ;
+  textmessage_sender_init(asyncout, fd[2]) ;
+  if (!textmessage_timed_send(asyncout, after, afterlen, deadline, stamp)) goto err ;
+  return 1 ;
+
+ err:
+  fd_close(fd[2]) ;
+  fd_close(fd[1]) ;
+  return 0 ;
+}
diff --git a/src/libunixonacid/textclient_start.c b/src/libunixonacid/textclient_start.c
new file mode 100644
index 0000000..8cb7bcd
--- /dev/null
+++ b/src/libunixonacid/textclient_start.c
@@ -0,0 +1,116 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+#include <skalibs/nonposix.h>
+#include <sys/uio.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <skalibs/error.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/webipc.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-timed.h>
+#include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
+
+union aligner_u
+{
+  struct cmsghdr cmsghdr ;
+  int i ;
+} ;
+
+static int getfd (void *p)
+{
+  return ((int *)p)[0] ;
+}
+
+static ssize_t get (void *p)
+{
+  static int const awesomeflags =
+#ifdef SKALIBS_HASMSGDONTWAIT
+    MSG_DONTWAIT
+#else
+    0
+#endif
+    |
+#ifdef SKALIBS_HASCMSGCLOEXEC
+    MSG_CMSG_CLOEXEC
+#else
+    0
+#endif
+    ;
+  struct cmsghdr *c ;
+  int *fd = p ;
+  ssize_t r ;
+  union aligner_u ancilbuf[1 + (CMSG_SPACE(sizeof(int)) - 1) / sizeof(union aligner_u)] ;
+  char ch ;
+  struct iovec v = { .iov_base = &ch, .iov_len = 1 } ;
+  struct msghdr msghdr =
+  {
+    .msg_name = 0,
+    .msg_namelen = 0,
+    .msg_iov = &v,
+    .msg_iovlen = 1,
+    .msg_flags = 0,
+    .msg_control = ancilbuf,
+    .msg_controllen = CMSG_SPACE(sizeof(int))
+  } ;
+  do r = recvmsg(fd[0], &msghdr, awesomeflags) ;
+  while (r < 0 && errno == EINTR) ;
+  if (r <= 0) return sanitize_read(r) ;
+  c = CMSG_FIRSTHDR(&msghdr) ;
+  if (ch != '|'
+   || !c
+   || c->cmsg_level != SOL_SOCKET
+   || c->cmsg_type != SCM_RIGHTS
+   || (size_t)(c->cmsg_len - (CMSG_DATA(c) - (unsigned char *)c)) != sizeof(int)) return (errno = EPROTO, -1) ;
+#ifndef SKALIBS_HASCMSGCLOEXEC
+  if (coe(*(int *)CMSG_DATA(c)) < 0)
+  {
+    fd_close(*(int *)CMSG_DATA(c)) ;
+    return -1 ;
+  }
+#endif
+  fd[1] = *(int *)CMSG_DATA(c) ;
+  return 1 ;
+}
+
+
+int textclient_start (textclient_t *a, char const *path, uint32_t options, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
+{
+  struct iovec v ;
+  int fd[2] ;
+  ssize_t r ;
+  fd[0] = ipc_stream_nbcoe() ;
+  if (fd[0] < 0) return 0 ;
+  if (!ipc_timed_connect(fd[0], path, deadline, stamp)) goto err ;
+  textmessage_sender_init(&a->syncout, fd[0]) ;
+  if (!textmessage_timed_send(&a->syncout, before, beforelen, deadline, stamp)) goto ferr ;
+  textmessage_receiver_init(&a->syncin, fd[0], a->syncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
+  r = timed_get(fd, &getfd, &get, deadline, stamp) ;
+  if (!r) errno = EPIPE ;
+  if (r <= 0) goto aerr ;
+  if (sanitize_read(textmessage_timed_receive(&a->syncin, &v, deadline, stamp)) <= 0) goto perr ;
+  if (v.iov_len != afterlen || memcmp(v.iov_base, after, afterlen)) { errno = EPROTO ; goto perr ; }
+  textmessage_receiver_init(&a->asyncin, fd[1], a->asyncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
+  if (sanitize_read(textmessage_timed_receive(&a->asyncin, &v, deadline, stamp)) <= 0) goto serr ;
+  if (v.iov_len != afterlen || memcmp(v.iov_base, after, afterlen)) goto berr ;
+  a->pid = 0 ;
+  a->options = options & ~TEXTCLIENT_OPTION_WAITPID ;
+  return 1 ;
+
+ berr:
+  errno = EPROTO ;
+ serr:
+  textmessage_receiver_free(&a->asyncin) ;
+ perr:
+  fd_close(fd[1]) ;
+ aerr:
+  textmessage_receiver_free(&a->syncin) ;
+ ferr:
+  textmessage_sender_free(&a->syncout) ;
+ err:
+  fd_close(fd[0]) ;
+  return 0 ;
+}
diff --git a/src/libunixonacid/textclient_startf.c b/src/libunixonacid/textclient_startf.c
new file mode 100644
index 0000000..fd724cd
--- /dev/null
+++ b/src/libunixonacid/textclient_startf.c
@@ -0,0 +1,34 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <string.h>
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/textmessage.h>
+#include <skalibs/textclient.h>
+
+int textclient_startf (textclient_t *a, char const *const *argv, char const *const *envp, uint32_t options, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
+{
+  struct iovec v ;
+  int fd[3] ;
+  pid_t pid = child_spawn(argv[0], argv, envp, fd, 3) ;
+  if (!pid) return 0 ;
+  textmessage_receiver_init(&a->syncin, fd[0], a->syncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
+  textmessage_receiver_init(&a->asyncin, fd[2], a->asyncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
+  textmessage_sender_init(&a->syncout, fd[1]) ;
+  a->pid = pid ;
+  a->options = options ;
+  if (!textclient_exchange(a, before, beforelen, &v, deadline, stamp)) goto err ;
+  if (v.iov_len != afterlen || memcmp(v.iov_base, after, afterlen)) goto errproto ;
+  if (sanitize_read(textmessage_timed_receive(&a->asyncin, &v, deadline, stamp)) <= 0) goto err ;
+  if (v.iov_len != afterlen || memcmp(v.iov_base, after, afterlen)) goto errproto ;
+  return 1 ;
+
+ errproto:
+  errno = EPROTO ;
+ err:
+  textclient_end(a) ;
+  return 0 ;
+}
diff --git a/src/libunixonacid/textmessage_put.c b/src/libunixonacid/textmessage_put.c
index a6eb6ca..5b7d944 100644
--- a/src/libunixonacid/textmessage_put.c
+++ b/src/libunixonacid/textmessage_put.c
@@ -15,7 +15,7 @@ int textmessage_put (textmessage_sender_t *ts, char const *s, size_t len)
     { .iov_base = pack, .iov_len = 4 },
     { .iov_base = (char *)s, .iov_len = len }
   } ;
-  if (len > UINT32_MAX) return (errno = EINVAL, 0) ;
+  if (len > TEXTMESSAGE_MAXLEN) return (errno = EINVAL, 0) ;
   uint32_pack_big(pack, (uint32_t)len) ;
   return bufalloc_putv(&ts->out, v, 2) ;
 }
diff --git a/src/libunixonacid/textmessage_putv.c b/src/libunixonacid/textmessage_putv.c
index c144505..759ce84 100644
--- a/src/libunixonacid/textmessage_putv.c
+++ b/src/libunixonacid/textmessage_putv.c
@@ -13,7 +13,7 @@ int textmessage_putv (textmessage_sender_t *ts, struct iovec const *v, unsigned
   size_t len = siovec_len(v, n) ;
   char pack[4] ;
   struct iovec vv[n+1] ;
-  if (len > UINT32_MAX) return (errno = EINVAL, 0) ;
+  if (len > TEXTMESSAGE_MAXLEN) return (errno = EINVAL, 0) ;
   vv[0].iov_base = pack ;
   vv[0].iov_len = 4 ;
   for (unsigned int i = 0 ; i < n ; i++) vv[i+1] = v[i] ;
diff --git a/src/libunixonacid/textmessage_receiver_0.c b/src/libunixonacid/textmessage_receiver_0.c
index f21b396..ab883de 100644
--- a/src/libunixonacid/textmessage_receiver_0.c
+++ b/src/libunixonacid/textmessage_receiver_0.c
@@ -2,9 +2,8 @@
 
 /* MT-unsafe */
 
-#include <stdint.h>
 #include <skalibs/buffer.h>
 #include <skalibs/textmessage.h>
 
 static char buf[BUFFER_INSIZE] ;
-textmessage_receiver_t textmessage_receiver_0_ = TEXTMESSAGE_RECEIVER_INIT(0, buf, BUFFER_INSIZE, UINT32_MAX) ;
+textmessage_receiver_t textmessage_receiver_0_ = TEXTMESSAGE_RECEIVER_INIT(0, buf, BUFFER_INSIZE, TEXTMESSAGE_MAXLEN) ;