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author | Jeremy Kerr <jk@ozlabs.org> | 2013-08-08 14:40:59 +0800 |
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committer | Jeremy Kerr <jk@ozlabs.org> | 2013-08-08 16:28:39 +0800 |
commit | a70807730ef59efc4116556ecabe1b9f70ce605b (patch) | |
tree | e23003459b930003ad6ab06f71ac7fb7aa014b1f /discover/file.c | |
parent | bee85b3946d50bc4ee02ab889f4b3a9cd0defe98 (diff) | |
download | talos-petitboot-a70807730ef59efc4116556ecabe1b9f70ce605b.tar.gz talos-petitboot-a70807730ef59efc4116556ecabe1b9f70ce605b.zip |
discover: separate file-reading code into file.c
We'll need to read files in the network config code, so add a 'file'
object, containing the read_file function.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Diffstat (limited to 'discover/file.c')
-rw-r--r-- | discover/file.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/discover/file.c b/discover/file.c new file mode 100644 index 0000000..269421c --- /dev/null +++ b/discover/file.c @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2013 Jeremy Kerr <jk@ozlabs.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <fcntl.h> +#include <unistd.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include <talloc/talloc.h> + +#include "file.h" + +static const int max_file_size = 1024 * 1024; + +int read_file(void *ctx, const char *filename, char **bufp, int *lenp) +{ + struct stat statbuf; + int rc, fd, i, len; + char *buf; + + fd = open(filename, O_RDONLY); + if (fd < 0) + return -1; + + rc = fstat(fd, &statbuf); + if (rc < 0) + goto err_close; + + len = statbuf.st_size; + if (len > max_file_size) + goto err_close; + + buf = talloc_array(ctx, char, len + 1); + if (!buf) + goto err_close; + + for (i = 0; i < len; i += rc) { + rc = read(fd, buf + i, len - i); + + /* unexpected EOF: trim and return */ + if (rc == 0) { + len = i; + break; + } + + if (rc < 0) + goto err_free; + + } + + buf[len] = '\0'; + + close(fd); + *bufp = buf; + *lenp = len; + return 0; + +err_free: + talloc_free(buf); +err_close: + close(fd); + return -1; +} |