[PATCH 4/6] slip: Use c_stdin and c_stdout in er everywhere

[Ian Jackson]

The userv exec context er needs to contain both ends of the pipe, so
that the child can close the unused ends.

So move c_stdin and c_stdout into er, change all references to them,
and abolish er->in and er->out.

No functional change yet in this patch.

Signed-off-by: Ian Jackson <ijackson at chiark.greenend.org.uk>
---
 slip.c |   24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/slip.c b/slip.c
index 2d45370..38b2ca8 100644
--- a/slip.c
+++ b/slip.c
@@ -250,8 +250,8 @@ static void userv_userv_callback(void *sst, pid_t pid, int status)
 struct userv_entry_rec {
     cstring_t path;
     const char **argv;
-    int in;
-    int out;
+    int c_stdin[2];
+    int c_stdout[2];
     /* XXX perhaps we should collect and log stderr? */
 };
 
@@ -259,8 +259,8 @@ static void userv_entry(void *sst)
 {
     struct userv_entry_rec *st=sst;
 
-    dup2(st->in,0);
-    dup2(st->out,1);
+    dup2(st->c_stdin[0],0);
+    dup2(st->c_stdout[1],1);
 
     /* XXX close all other fds */
     setsid();
@@ -274,8 +274,6 @@ static void userv_entry(void *sst)
 static void userv_invoke_userv(struct userv *st)
 {
     struct userv_entry_rec er[1];
-    int c_stdin[2];
-    int c_stdout[2];
     string_t addrs;
     string_t nets;
     string_t s;
@@ -326,17 +324,15 @@ static void userv_invoke_userv(struct userv *st)
     st->slip.pending_esc=False;
 
     /* Invoke userv */
-    if (pipe(c_stdin)!=0) {
+    if (pipe(er->c_stdin)!=0) {
 	fatal_perror("userv_invoke_userv: pipe(c_stdin)");
     }
-    if (pipe(c_stdout)!=0) {
+    if (pipe(er->c_stdout)!=0) {
 	fatal_perror("userv_invoke_userv: pipe(c_stdout)");
     }
-    st->txfd=c_stdin[1];
-    st->rxfd=c_stdout[0];
+    st->txfd=er->c_stdin[1];
+    st->rxfd=er->c_stdout[0];
 
-    er->in=c_stdin[0];
-    er->out=c_stdout[1];
     /* The arguments are:
        userv
        service-user
@@ -354,8 +350,8 @@ static void userv_invoke_userv(struct userv *st)
 
     st->pid=makesubproc(userv_entry, userv_userv_callback,
 			er, st, st->slip.nl.name);
-    close(er->in);
-    close(er->out);
+    close(er->c_stdin[0]);
+    close(er->c_stdout[1]);
     free(er->argv);
     free(addrs);
     free(nets);
-- 
1.7.10.4