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[Qemu-devel] [PATCH 1/4] curl: Fix parsing of readahead option from file
From: |
Matthew Booth |
Subject: |
[Qemu-devel] [PATCH 1/4] curl: Fix parsing of readahead option from filename |
Date: |
Thu, 8 May 2014 09:42:17 +0100 |
curl_parse_filename wasn't removing the option string from the url,
resulting in a 404.
This change is a rewrite of the previous parsing behaviour, and
also changes the option syntax. The new syntax is:
http://example.com/path?query[sslverify=off:readahead=64k]
The new syntax is well defined as long as square brackets in the URI
are escaped.
This change is also preparation for the addition of more options.
Signed-off-by: Matthew Booth <address@hidden>
---
block/curl.c | 101 +++++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 67 insertions(+), 34 deletions(-)
diff --git a/block/curl.c b/block/curl.c
index d2f1084..e31b6f3 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -46,12 +46,15 @@
#define CURL_NUM_STATES 8
#define CURL_NUM_ACB 8
#define SECTOR_SIZE 512
-#define READ_AHEAD_SIZE (256 * 1024)
+#define READ_AHEAD_DEFAULT (256 * 1024)
#define FIND_RET_NONE 0
#define FIND_RET_OK 1
#define FIND_RET_WAIT 2
+#define CURL_BLOCK_OPT_URL "url"
+#define CURL_BLOCK_OPT_READAHEAD "readahead"
+
struct BDRVCURLState;
typedef struct CURLAIOCB {
@@ -393,45 +396,74 @@ static void curl_clean_state(CURLState *s)
s->in_use = 0;
}
+/* Parse options out of @filename, which should be a URI.
+ *
+ * Options are given as a sequence of key=value pairs separated by colons and
+ * enclosed in square brackets at the end of the URI. e.g.:
+ *
+ * http://example.com/path?query[sslverify=off:readahead=64k]
+ *
+ * Consequently, if a valid URI ends with a block enclosed by square brackets,
+ * those brackets MUST be URI encoded.
+ */
static void curl_parse_filename(const char *filename, QDict *options,
Error **errp)
{
+ char *file = g_strdup(filename);
+ char *end = file + strlen(file) - 1;
+
+ /* Don't fail if we've been passed an empty string.
+ * Only examine strings with a trailing ']'
+ */
+ if (end >= file && ']' == *end) {
+ /* Look for the opening bracket */
+ char *open = memrchr(file, '[', end - file);
+
+ if (NULL != open) {
+ /* NULL terminate the preceding URI by overwriting the opening
+ * bracket */
+ *open = '\0';
+ char *opt_block = open + 1;
+
+ /* NULL terminate the option string by overwriting the closing
+ * bracket */
+ *end = '\0';
+
+ /* Parse each colon-separated option */
+ char *saveptr;
+ char *opt = strtok_r(opt_block, ":", &saveptr);
+ while (NULL != opt) {
+ size_t opt_len = strlen(opt);
+
+ /* Look for an equals sign */
+ char *equals = memchr(opt, '=', opt_len);
+ if (NULL == equals) {
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt,
+ "a value");
+ goto out;
+ }
- #define RA_OPTSTR ":readahead="
- char *file;
- char *ra;
- const char *ra_val;
- int parse_state = 0;
-
- file = g_strdup(filename);
-
- /* Parse a trailing ":readahead=#:" param, if present. */
- ra = file + strlen(file) - 1;
- while (ra >= file) {
- if (parse_state == 0) {
- if (*ra == ':') {
- parse_state++;
- } else {
- break;
- }
- } else if (parse_state == 1) {
- if (*ra > '9' || *ra < '0') {
- char *opt_start = ra - strlen(RA_OPTSTR) + 1;
- if (opt_start > file &&
- strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) {
- ra_val = ra + 1;
- ra -= strlen(RA_OPTSTR) - 1;
- *ra = '\0';
- qdict_put(options, "readahead", qstring_from_str(ra_val));
+ size_t key_len = equals - opt;
+ char *value = equals + 1;
+
+ if (key_len == strlen(CURL_BLOCK_OPT_READAHEAD) &&
+ memcmp(opt, CURL_BLOCK_OPT_READAHEAD, key_len) == 0) {
+ qdict_put(options, CURL_BLOCK_OPT_READAHEAD,
+ qstring_from_str(value));
+ } else {
+ *equals = '\0';
+ error_set(errp, QERR_INVALID_PARAMETER, opt);
+ goto out;
}
- break;
+
+ opt = strtok_r(NULL, ":", &saveptr);
}
}
- ra--;
}
- qdict_put(options, "url", qstring_from_str(file));
+ qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(file));
+out:
g_free(file);
}
@@ -440,12 +472,12 @@ static QemuOptsList runtime_opts = {
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
- .name = "url",
+ .name = CURL_BLOCK_OPT_URL,
.type = QEMU_OPT_STRING,
.help = "URL to open",
},
{
- .name = "readahead",
+ .name = CURL_BLOCK_OPT_READAHEAD,
.type = QEMU_OPT_SIZE,
.help = "Readahead size",
},
@@ -477,14 +509,15 @@ static int curl_open(BlockDriverState *bs, QDict
*options, int flags,
goto out_noclean;
}
- s->readahead_size = qemu_opt_get_size(opts, "readahead", READ_AHEAD_SIZE);
+ s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
+ READ_AHEAD_DEFAULT);
if ((s->readahead_size & 0x1ff) != 0) {
error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
s->readahead_size);
goto out_noclean;
}
- file = qemu_opt_get(opts, "url");
+ file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
if (file == NULL) {
error_setg(errp, "curl block driver requires an 'url' option");
goto out_noclean;
--
1.9.0
- [Qemu-devel] Curl updates, Matthew Booth, 2014/05/08
- [Qemu-devel] [PATCH 1/4] curl: Fix parsing of readahead option from filename,
Matthew Booth <=
- [Qemu-devel] [PATCH 3/4] curl: Add usage documentation, Matthew Booth, 2014/05/08
- [Qemu-devel] [PATCH 2/4] curl: Add sslverify option, Matthew Booth, 2014/05/08
- [Qemu-devel] [PATCH 4/4] curl: Fix build when curl_multi_socket_action isn't available, Matthew Booth, 2014/05/08
- Re: [Qemu-devel] Curl updates, Eric Blake, 2014/05/13