Add support in the wallet client for store of binary data

Refactor the wallet client code to use remctl_commandv and send stores
with data containing nul.

4 files changed, 84 insertions, 48 deletions

diff --git a/client/file.c b/client/file.c
index c9edf3a..66d5f63 100644
--- a/client/file.c
+++ b/client/file.c
@@ -115,14 +115,13 @@ get_file(struct remctl *r, const char *prefix, const char *type,
 
 
 /*
- * Read all of a file into memory and return the contents as a newly allocated
- * string.  Handles a file name of "-" to mean standard input.  Dies on any
- * failure.
- *
- * This will need modification later when we want to handle nul characters.
+ * Read all of a file into memory and return the contents in newly allocated
+ * memory.  Returns the size of the file contents in the second argument if
+ * it's not NULL.  Handles a file name of "-" to mean standard input.  Dies on
+ * any failure.
  */
-char *
-read_file(const char *name)
+void *
+read_file(const char *name, size_t *length)
 {
     char *contents;
     size_t size, offset;
@@ -140,7 +139,7 @@ read_file(const char *name)
             sysdie("cannot open file %s", name);
         if (fstat(fd, &st) < 0)
             sysdie("cannot stat file %s", name);
-        size = st.st_size + 1;
+        size = st.st_size;
         contents = xmalloc(size);
     }
     offset = 0;
@@ -157,8 +156,7 @@ read_file(const char *name)
         offset += status;
     } while (status > 0);
     close(fd);
-    contents[offset] = '\0';
-    if (memchr(contents, '\0', offset) != NULL)
-        die("cannot yet handle file data containing nul characters");
+    if (length != NULL)
+        *length = offset;
     return contents;
 }
diff --git a/client/internal.h b/client/internal.h
index 7fe962b..d82196c 100644
--- a/client/internal.h
+++ b/client/internal.h
@@ -17,6 +17,7 @@
 
 /* Forward declarations to avoid unnecessary includes. */
 struct remctl;
+struct iovec;
 
 BEGIN_DECLS
 
@@ -29,14 +30,18 @@ void kinit(krb5_context, const char *principal);
 void kdestroy(void);
 
 /*
- * Given a remctl object, run a remctl command.  If data is non-NULL, saves
- * the standard output from the command into data with the length in length.
- * Otherwise, prints it to standard output.  Either way, prints standard error
- * output and errors to standard error and returns the exit status or 255 for
- * a remctl internal error.
+ * Given a remctl object, either a NULL-terminated array of strings or an
+ * array of iovecs and the number of elements in the array, and optional data
+ * and size output variables, run a remctl command.  If data is non-NULL,
+ * saves the standard output from the command into data with the length in
+ * length.  Otherwise, prints it to standard output.  Either way, prints
+ * standard error output and errors to standard error and returns the exit
+ * status or 255 for a remctl internal error.
  */
 int run_command(struct remctl *, const char **command, char **data,
                 size_t *length);
+int run_commandv(struct remctl *, const struct iovec *command, size_t count,
+                 char **data, size_t *length);
 
 /*
  * Check whether an object exists using the exists wallet interface.  Returns
@@ -91,12 +96,12 @@ void write_srvtab(krb5_context, const char *srvtab, const char *principal,
                   const char *keytab);
 
 /*
- * Read all of a file into memory and return the contents as a newly allocated
- * string.  Handles a file name of "-" to mean standard input.  Dies on any
- * failure.  This will need modification later when we want to handle nul
- * characters.
+ * Read all of a file into memory and return the contents in newly allocated
+ * memory.  Handles a file name of "-" to mean standard input.  Stores the
+ * length of the data in the second argument if it isn't NULL.  Dies on any
+ * failure.
  */
-char *read_file(const char *);
+void *read_file(const char *, size_t *);
 
 END_DECLS
 
diff --git a/client/remctl.c b/client/remctl.c
index a4ff097..5a541d5 100644
--- a/client/remctl.c
+++ b/client/remctl.c
@@ -18,15 +18,14 @@
 
 
 /*
- * Given a remctl connection and a command, run the command.
- *
- * If data is non-NULL, save the output in it and return the length in length.
- * Otherwise, send any output to stdout.  Either way, send error output to
- * stderr, and return the exit status (or 255 if there is an error).
+ * Retrieve the results of a remctl command, which should be issued prior to
+ * calling this function.  If data is non-NULL, save the output in it and
+ * return the length in length.  Otherwise, send any output to stdout.  Either
+ * way, send error output to stderr, and return the exit status (or 255 if
+ * there is an error).
  */
-int
-run_command(struct remctl *r, const char **command, char **data,
-            size_t *length)
+static int
+command_results(struct remctl *r, char **data, size_t *length)
 {
     struct remctl_output *output;
     int status = 255;
@@ -35,10 +34,6 @@ run_command(struct remctl *r, const char **command, char **data,
         *data = NULL;
     if (length != NULL)
         *length = 0;
-    if (!remctl_command(r, command)) {
-        warn("%s", remctl_error(r));
-        return 255;
-    }
     do {
         output = remctl_output(r);
         switch (output->type) {
@@ -74,6 +69,40 @@ run_command(struct remctl *r, const char **command, char **data,
 
 
 /*
+ * Given a remctl connection and a NULL-terminated array of strings, run the
+ * command and return the results using command_results, optionally putting
+ * output into the data variable.
+ */
+int
+run_command(struct remctl *r, const char **command, char **data,
+            size_t *length)
+{
+    if (!remctl_command(r, command)) {
+        warn("%s", remctl_error(r));
+        return 255;
+    }
+    return command_results(r, data, length);
+}
+
+
+/*
+ * Given a remctl connection, an array of iovecs, and the length of the array,
+ * run the command and return the results using command_results, optionally
+ * putting output into the data variable.
+ */
+int
+run_commandv(struct remctl *r, const struct iovec *command, size_t count,
+             char **data, size_t *length)
+{
+    if (!remctl_commandv(r, command, count)) {
+        warn("%s", remctl_error(r));
+        return 255;
+    }
+    return command_results(r, data, length);
+}
+
+
+/*
  * Check whether an object exists using the exists wallet interface.  Returns
  * true if it does, false if it doesn't, and dies on remctl errors.
  */
diff --git a/client/wallet.c b/client/wallet.c
index ce0f4e7..dc4fe18 100644
--- a/client/wallet.c
+++ b/client/wallet.c
@@ -135,7 +135,8 @@ main(int argc, char *argv[])
     krb5_error_code retval;
     struct options options;
     int option, i, status;
-    const char **command;
+    struct iovec *command;
+    size_t count, length;
     const char *file = NULL;
     const char *srvtab = NULL;
     struct remctl *r;
@@ -241,24 +242,27 @@ main(int argc, char *argv[])
             status = get_file(r, options.type, argv[1], argv[2], file);
         }
     } else {
+        count = argc + 1;
         if (strcmp(argv[0], "store") == 0) {
             if (argc > 4)
                 die("too many arguments");
-            else if (argc == 4)
-                command = xmalloc(sizeof(char *) * (argc + 2));
-            else
-                command = xmalloc(sizeof(char *) * (argc + 3));
-        } else
-            command = xmalloc(sizeof(char *) * (argc + 2));
-        command[0] = options.type;
-        for (i = 0; i < argc; i++)
-            command[i + 1] = argv[i];
+            else if (argc < 4)
+                count++;
+        }
+        command = xmalloc(sizeof(struct iovec) * count);
+        command[0].iov_base = (char *) options.type;
+        command[0].iov_len = strlen(options.type);
+        for (i = 0; i < argc; i++) {
+            command[i + 1].iov_base = argv[i];
+            command[i + 1].iov_len = strlen(argv[i]);
+        }
         if (strcmp(argv[0], "store") == 0 && argc < 4) {
-            command[argc + 1] = read_file(file == NULL ? "-" : file);
-            command[argc + 2] = NULL;
-        } else
-            command[argc + 1] = NULL;
-        status = run_command(r, command, NULL, NULL);
+            if (file == NULL)
+                file = "-";
+            command[argc + 1].iov_base = read_file(file, &length);
+            command[argc + 1].iov_len = length;
+        }
+        status = run_commandv(r, command, count, NULL, NULL);
     }
     remctl_close(r);
     krb5_free_context(ctx);