netutils/rexec/rexecd: supports remote execution and interaction

using popen with r+,w+ mode to interact with the remote service on the command line, supporting input and output until the local voluntarily exits or the remote service ends. Signed-off-by: dongjiuzhu1 <[email protected]>
apache · Jul 30, 2023 · fb7dafc · fb7dafc
1 parent e86f6c1
commit fb7dafc
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Showing 2 changed files with 81 additions and 13 deletions.
diff --git a/netutils/rexec/rexec.c b/netutils/rexec/rexec.c
@@ -22,6 +22,7 @@
  * Included Files
  ****************************************************************************/
 
+#include <sys/poll.h>
 #include <sys/types.h>
 #include <getopt.h>
 #include <netdb.h>
@@ -82,6 +83,7 @@ static void usage(FAR const char *progname)
 static int do_rexec(FAR struct rexec_arg_s *arg)
 {
   char buffer[REXEC_BUFSIZE];
+  struct pollfd fds[2];
   int sock;
   int ret;
 
@@ -93,16 +95,52 @@ static int do_rexec(FAR struct rexec_arg_s *arg)
       return sock;
     }
 
+  memset(fds, 0, sizeof(fds));
+  fds[0].fd = sock;
+  fds[0].events = POLLIN;
+  fds[1].fd = STDIN_FILENO;
+  fds[1].events = POLLIN;
+
   while (1)
     {
-      ret = read(sock, buffer, REXEC_BUFSIZE);
+      ret = poll(fds, 2, -1);
       if (ret <= 0)
         {
-          break;
+          continue;
+        }
+
+      if (fds[0].revents & POLLIN)
+        {
+          ret = read(sock, buffer, REXEC_BUFSIZE);
+          if (ret <= 0)
+            {
+              break;
+            }
+
+          ret = write(STDOUT_FILENO, buffer, ret);
+          if (ret < 0)
+            {
+              break;
+            }
+        }
+
+      if (fds[1].revents & POLLIN)
+        {
+          ret = read(STDIN_FILENO, buffer, REXEC_BUFSIZE);
+          if (ret <= 0)
+            {
+              break;
+            }
+
+          ret = write(sock, buffer, ret);
+          if (ret < 0)
+            {
+              break;
+            }
         }
 
-      ret = write(STDOUT_FILENO, buffer, ret);
-      if (ret < 0)
+      if (((fds[0].revents | fds[1].revents) & POLLHUP) &&
+          ((fds[0].revents | fds[1].revents) & POLLIN) == 0)
         {
           break;
         }

diff --git a/netutils/rexecd/rexecd.c b/netutils/rexecd/rexecd.c
@@ -80,10 +80,10 @@ static int getstr(int fd, FAR char *buf)
 static FAR void *doit(pthread_addr_t pvarg)
 {
   char buf[REXECD_BUFSIZE];
+  struct pollfd fds[2];
   FAR FILE *fp;
   int sock = (int)pvarg;
   int ret;
-  int len;
 
   /* we need to read err_sock, user and passwd, but ignore them */
 
@@ -94,31 +94,61 @@ static FAR void *doit(pthread_addr_t pvarg)
   /* we need to read command */
 
   getstr(sock, buf);
-  fp = popen(buf, "r");
+  fp = popen(buf, "r+");
   if (!fp)
     {
       goto errout;
     }
 
+  memset(fds, 0, sizeof(fds));
+  fds[0].fd = fileno(fp);
+  fds[0].events = POLLIN;
+  fds[1].fd = sock;
+  fds[1].events = POLLIN;
+
   while (1)
     {
-      ret = fread(buf, 1, REXECD_BUFSIZE, fp);
+      ret = poll(fds, 2, -1);
       if (ret <= 0)
         {
-          break;
+          continue;
         }
 
-      do
+      if (fds[0].revents & POLLIN)
         {
-          len = write(sock, buf, ret);
-          if (len <= 0)
+          ret = read(fileno(fp), buf, REXECD_BUFSIZE);
+          if (ret <= 0)
+            {
+              break;
+            }
+
+          ret = write(sock, buf, ret);
+          if (ret < 0)
             {
               break;
             }
+        }
 
-          ret -= len;
+      if (fds[1].revents & POLLIN)
+        {
+          ret = read(sock, buf, REXECD_BUFSIZE);
+          if (ret <= 0)
+            {
+              break;
+            }
+
+          ret = write(fileno(fp), buf, ret);
+          if (ret < 0)
+            {
+              break;
+            }
+        }
+
+      if (((fds[0].revents | fds[1].revents) & POLLHUP) &&
+          ((fds[0].revents | fds[1].revents) & POLLIN) == 0)
+        {
+          break;
         }
-      while (ret > 0);
     }
 
   pclose(fp);