discover/boot: Allow boot hooks to alter boot data

[petitboot] / lib / system / system.c

diff --git a/lib/system/system.c b/lib/system/system.c
index cbf6b9fc5a8b43472dc5c4ea7b823e83b196ee8a..528e134127f307f17d9dcfaa70b2b1ef60eb7a52 100644 (file)
--- a/lib/system/system.c
+++ b/lib/system/system.c
@@ -24,9 +24,10 @@ const struct pb_system_apps pb_system_apps = {
        .shutdown       = HOST_PROG_SHUTDOWN,
        .sftp           = HOST_PROG_SFTP,
        .tftp           = HOST_PROG_TFTP,
-       .udevadm        = HOST_PROG_UDEVADM,
        .umount         = HOST_PROG_UMOUNT,
        .wget           = HOST_PROG_WGET,
+       .ip             = HOST_PROG_IP,
+       .udhcpc         = HOST_PROG_UDHCPC,
 };
 
 int pb_mkdir_recursive(const char *dir)
@@ -101,6 +102,40 @@ int pb_rmdir_recursive(const char *base, const char *dir)
        return 0;
 }
 
+static int read_pipe(void *ctx, int fd, char **bufp, int *lenp)
+{
+       int rc, len, alloc_len;
+       char *buf;
+
+       alloc_len = 4096;
+       len = 0;
+
+       buf = talloc_array(ctx, char, alloc_len);
+
+       for (;;) {
+               rc = read(fd, buf, alloc_len - len - 1);
+               if (rc <= 0)
+                       break;
+
+               len += rc;
+               if (len == alloc_len - 1) {
+                       alloc_len *= 2;
+                       buf = talloc_realloc(ctx, buf, char, alloc_len);
+               }
+       }
+
+       if (rc < 0) {
+               talloc_free(buf);
+               return rc;
+       }
+
+       buf[len] = '\0';
+       *bufp = buf;
+       *lenp = len;
+
+       return 0;
+}
+
 /**
  * pb_run_cmd - Run the supplied command.
  * @cmd_argv: An argument list array for execv.
@@ -109,15 +144,25 @@ int pb_rmdir_recursive(const char *base, const char *dir)
  */
 
 int pb_run_cmd(const char *const *cmd_argv, int wait, int dry_run)
+{
+       return pb_run_cmd_pipe(cmd_argv, wait, dry_run, NULL, NULL, NULL);
+}
+
+int pb_run_cmd_pipe(const char *const *cmd_argv, int wait, int dry_run,
+               void *ctx, char **stdout_buf, int *stdout_buf_len)
 {
 #if defined(DEBUG)
        enum {do_debug = 1};
 #else
        enum {do_debug = 0};
 #endif
-       int status;
+       int status, pipefd[2];
        pid_t pid;
 
+       assert(!stdout_buf || wait);
+       assert(!stdout_buf || ctx);
+       assert(!stdout_buf || stdout_buf_len);
+
        if (do_debug) {
                const char *const *p = cmd_argv;
 
@@ -132,9 +177,22 @@ int pb_run_cmd(const char *const *cmd_argv, int wait, int dry_run)
                pb_log("%s: %s%s\n", __func__, (dry_run ? "(dry-run) " : ""),
                        cmd_argv[0]);
 
+       if (stdout_buf) {
+               *stdout_buf = NULL;
+               *stdout_buf_len = 0;
+       }
+
        if (dry_run)
                return 0;
 
+       if (stdout_buf) {
+               status = pipe(pipefd);
+               if (status) {
+                       pb_log("pipe failed");
+                       return -1;
+               }
+       }
+
        pid = fork();
 
        if (pid == -1) {
@@ -142,12 +200,17 @@ int pb_run_cmd(const char *const *cmd_argv, int wait, int dry_run)
                return -1;
        }
 
+
        if (pid == 0) {
                int log = fileno(pb_log_get_stream());
 
                /* Redirect child output to log. */
 
-               status = dup2(log, STDOUT_FILENO);
+               if (stdout_buf) {
+                       status = dup2(pipefd[1], STDOUT_FILENO);
+               } else {
+                       status = dup2(log, STDOUT_FILENO);
+               }
                assert(status != -1);
 
                status = dup2(log, STDERR_FILENO);
@@ -161,6 +224,13 @@ int pb_run_cmd(const char *const *cmd_argv, int wait, int dry_run)
        if (!wait && !waitpid(pid, &status, WNOHANG))
                return 0;
 
+       if (stdout_buf) {
+               close(pipefd[1]);
+               status = read_pipe(ctx, pipefd[0], stdout_buf, stdout_buf_len);
+               if (status)
+                       return -1;
+       }
+
        if (waitpid(pid, &status, 0) == -1) {
                pb_log("%s: waitpid failed: %s\n", __func__,
                                strerror(errno));