From 467866fd55129d1149200c44849c08e9f71f33a7 Mon Sep 17 00:00:00 2001
From: Jann Horn <jann@thejh.net>
Date: Fri, 15 Nov 2013 19:17:38 +0100
Subject: [PATCH] add fopen_bistream and fnetopen

---
 io.c  | 36 +++++++++++++++++++++++++++++++++++-
 net.c |  8 ++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/io.c b/io.c
index 17ea4d6..ef1f912 100644
--- a/io.c
+++ b/io.c
@@ -4,7 +4,7 @@ HEADER #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdlib.h>
-#include <stdbool.h>
+HEADER #include <stdbool.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
@@ -181,3 +181,37 @@ PUBLIC_FN void *mmap_file(void *addr, size_t length, int prot, int flags, char *
   errno = errno_;
   return (r==MAP_FAILED) ? NULL : r;
 }
+
+// on error, fd remains unchanged, no matter whether you specified "keep" or not
+HEADER #define JH_OBS_KEEPFD 1
+HEADER #define JH_OBS_BUFFER 2
+PUBLIC_FN int fopen_bistream(FILE **in, FILE **out, int fd, int flags) {
+  // check input
+  if (fd < 0) goto err_out;
+  bool keep = flags & JH_OBS_KEEPFD;
+  bool buffer = flags & JH_OBS_BUFFER;
+
+  // create input FILE*
+  int in_fd = dup(fd);
+  if (in_fd < 0) goto err_out;
+  *in = fdopen(in_fd, "r");
+  if (!*in) { close(in_fd); goto err_out; }
+
+  // create output FILE*
+  int out_fd = keep ? dup(fd) : fd;
+  if (out_fd < 0) goto err_dup_out;
+  *out = fdopen(out_fd, "w");
+  if (!*out) { if (keep) close(out_fd); goto err_dup_out; }
+
+  // avoid buffering data unless the caller really wants it
+  if (!buffer) setbuf(*out, NULL);
+
+  // success!
+  return 0;
+
+
+err_dup_out:
+  fclose(*in);
+err_out:
+  return EAI_SYSTEM;
+}
\ No newline at end of file
diff --git a/net.c b/net.c
index d9b2d43..2fba39a 100644
--- a/net.c
+++ b/net.c
@@ -39,3 +39,11 @@ err_socket:
   freeaddrinfo(addrs);
   return EAI_SYSTEM;
 }
+
+PUBLIC_FN int fnetopen(FILE **in, FILE **out, const char *node, const char *service, const struct addrinfo *hints) {
+  int fd = netopen(node, service, hints);
+  if (fd < 0) return EAI_SYSTEM;
+  int ret = fopen_bistream(in, out, fd, 0);
+  if (ret) close(fd);
+  return ret;
+}
\ No newline at end of file
-- 
2.20.1