Add |opts| argument to android_fork_execvp_ext

to allow the caller to send data to the child's stdin.

Bug: 21725996
Change-Id: I818f5cf61045286c8d64a91b6d50f05740329be1

3 files changed, 48 insertions, 5 deletions

diff --git a/logwrapper/include/logwrap/logwrap.h b/logwrapper/include/logwrap/logwrap.h
index 4307a3055..449461f65 100644
--- a/logwrapper/include/logwrap/logwrap.h
+++ b/logwrapper/include/logwrap/logwrap.h
@@ -19,6 +19,7 @@
 #define __LIBS_LOGWRAP_H
 
 #include <stdbool.h>
+#include <stdint.h>
 
 __BEGIN_DECLS
 
@@ -53,6 +54,9 @@ __BEGIN_DECLS
  *           the specified log until the child has exited.
  *   file_path: if log_target has the LOG_FILE bit set, then this parameter
  *           must be set to the pathname of the file to log to.
+ *   opts: set to non-NULL if you want to use one or more of the
+ *           FORK_EXECVP_OPTION_* features.
+ *   opts_len: the length of the opts array. When opts is NULL, pass 0.
  *
  * Return value:
  *   0 when logwrap successfully run the child process and captured its status
@@ -68,8 +72,22 @@ __BEGIN_DECLS
 #define LOG_KLOG        2
 #define LOG_FILE        4
 
+/* Write data to child's stdin. */
+#define FORK_EXECVP_OPTION_INPUT    0
+
+struct AndroidForkExecvpOption {
+    int opt_type;
+    union {
+        struct {
+            const uint8_t* input;
+            size_t input_len;
+        } opt_input;
+    };
+};
+
 int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int_quit,
-        int log_target, bool abbreviated, char *file_path);
+        int log_target, bool abbreviated, char *file_path,
+        const struct AndroidForkExecvpOption* opts, size_t opts_len);
 
 /* Similar to above, except abbreviated logging is not available, and if logwrap
  * is true, logging is to the Android system log, and if false, there is no
@@ -79,7 +97,8 @@ static inline int android_fork_execvp(int argc, char* argv[], int *status,
                                      bool ignore_int_quit, bool logwrap)
 {
     return android_fork_execvp_ext(argc, argv, status, ignore_int_quit,
-                                   (logwrap ? LOG_ALOG : LOG_NONE), false, NULL);
+                                   (logwrap ? LOG_ALOG : LOG_NONE), false, NULL,
+                                   NULL, 0);
 }
 
 __END_DECLS
diff --git a/logwrapper/logwrap.c b/logwrapper/logwrap.c
index 777dafeff..c7b48358e 100644
--- a/logwrapper/logwrap.c
+++ b/logwrapper/logwrap.c
@@ -474,7 +474,8 @@ static void child(int argc, char* argv[]) {
 }
 
 int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int_quit,
-        int log_target, bool abbreviated, char *file_path) {
+        int log_target, bool abbreviated, char *file_path,
+        const struct AndroidForkExecvpOption* opts, size_t opts_len) {
     pid_t pid;
     int parent_ptty;
     int child_ptty;
@@ -483,6 +484,7 @@ int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int
     sigset_t blockset;
     sigset_t oldset;
     int rc = 0;
+    size_t i;
 
     rc = pthread_mutex_lock(&fd_mutex);
     if (rc) {
@@ -529,7 +531,13 @@ int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int
         pthread_sigmask(SIG_SETMASK, &oldset, NULL);
         close(parent_ptty);
 
-        // redirect stdout and stderr
+        // redirect stdin, stdout and stderr
+        for (i = 0; i < opts_len; ++i) {
+            if (opts[i].opt_type == FORK_EXECVP_OPTION_INPUT) {
+                dup2(child_ptty, 0);
+                break;
+            }
+        }
         dup2(child_ptty, 1);
         dup2(child_ptty, 2);
         close(child_ptty);
@@ -546,6 +554,22 @@ int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int
             sigaction(SIGQUIT, &ignact, &quitact);
         }
 
+        for (i = 0; i < opts_len; ++i) {
+            if (opts[i].opt_type == FORK_EXECVP_OPTION_INPUT) {
+                size_t left = opts[i].opt_input.input_len;
+                const uint8_t* input = opts[i].opt_input.input;
+                while (left > 0) {
+                    ssize_t res =
+                        TEMP_FAILURE_RETRY(write(parent_ptty, input, left));
+                    if (res < 0) {
+                        break;
+                    }
+                    left -= res;
+                    input += res;
+                }
+            }
+        }
+
         rc = parent(argv[0], parent_ptty, pid, status, log_target,
                     abbreviated, file_path);
     }
diff --git a/logwrapper/logwrapper.c b/logwrapper/logwrapper.c
index 9e0385db2..55b71c708 100644
--- a/logwrapper/logwrapper.c
+++ b/logwrapper/logwrapper.c
@@ -81,7 +81,7 @@ int main(int argc, char* argv[]) {
     }
 
     rc = android_fork_execvp_ext(argc, &argv[0], &status, true,
-                                 log_target, abbreviated, NULL);
+                                 log_target, abbreviated, NULL, NULL, 0);
     if (!rc) {
         if (WIFEXITED(status))
             rc = WEXITSTATUS(status);