sockets: Change inet_parse() to accept address specification without port
From: Bharata B Rao <bhar...@linux.vnet.ibm.com>
inet_parse() expects address:port. Change it to work without explicit port
specification. In addition, don't depend solely on the return value of
sscanf but also consider the value obtained for %n directive used in sscanf.
This ensures that the scanning of malformed inet address isn't flagged as
success.
Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
---
qemu-sockets.c | 32 +++++++++++++++++++++++++-------
1 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/qemu-sockets.c b/qemu-sockets.c
index c330fc5..627269f 100644
--- a/qemu-sockets.c
+++ b/qemu-sockets.c
@@ -376,26 +376,35 @@ err:
return -1;
}
-/* compatibility wrapper */
+/*
+ * sscanf could return positive return value indicating successful
+ * match and assignment even when it doesn't parse the input as per
+ * the format specified. Hence we are depending on %n to really determine if
+ * inputs were successfully scanned. Checking retval for EOF isn't strictly
+ * necessary, but just being extra careful.
+ */
int inet_parse(QemuOpts *opts, const char *str)
{
const char *optstr, *h;
char addr[64];
- char port[33];
- int pos;
+ char port[33] = {'\0'}; /* port is optional */
+ int ret, pos, addr_pos = -1, port_pos = -1;
/* parse address */
if (str[0] == ':') {
/* no host given */
addr[0] = '\0';
- if (1 != sscanf(str,":%32[^,]%n",port,&pos)) {
+ ret = sscanf(str, ":%32[^,]%n", port, &port_pos);
+ if (port_pos == -1 || ret == EOF) {
fprintf(stderr, "%s: portonly parse error (%s)\n",
__FUNCTION__, str);
return -1;
}
} else if (str[0] == '[') {
/* IPv6 addr */
- if (2 != sscanf(str,"[%64[^]]]:%32[^,]%n",addr,port,&pos)) {
+ ret = sscanf(str, "[%64[^]]]%n:%32[^,]%n", addr, &addr_pos,
+ port, &port_pos);
+ if (addr_pos == -1 || ret == EOF) {
fprintf(stderr, "%s: ipv6 parse error (%s)\n",
__FUNCTION__, str);
return -1;
@@ -403,7 +412,9 @@ int inet_parse(QemuOpts *opts, const char *str)
qemu_opt_set(opts, "ipv6", "on");
} else if (qemu_isdigit(str[0])) {
/* IPv4 addr */
- if (2 != sscanf(str,"%64[0-9.]:%32[^,]%n",addr,port,&pos)) {
+ ret = sscanf(str, "%64[0-9.]%n:%32[^,]%n", addr, &addr_pos,
+ port, &port_pos);
+ if (addr_pos == -1 || ret == EOF) {
fprintf(stderr, "%s: ipv4 parse error (%s)\n",
__FUNCTION__, str);
return -1;
@@ -411,7 +422,9 @@ int inet_parse(QemuOpts *opts, const char *str)
qemu_opt_set(opts, "ipv4", "on");
} else {
/* hostname */
- if (2 != sscanf(str,"%64[^:]:%32[^,]%n",addr,port,&pos)) {
+ ret = sscanf(str, "%64[^:]%n:%32[^,]%n", addr, &addr_pos,
+ port, &port_pos);
+ if (addr_pos == -1 || ret == EOF) {
fprintf(stderr, "%s: hostname parse error (%s)\n",
__FUNCTION__, str);
return -1;
@@ -421,6 +434,11 @@ int inet_parse(QemuOpts *opts, const char *str)
qemu_opt_set(opts, "port", port);
/* parse options */
+ if (port_pos != -1) {
+ pos = port_pos;
+ } else {
+ pos = addr_pos;
+ }
optstr = str + pos;
h = strstr(optstr, ",to=");
if (h)
