[PATCHv2 5/5] pktgen: Clean read user supplied flag mess

From: Dmitry Safonov
Date: Thu Jan 18 2018 - 13:32:00 EST


Don't use error-prone-brute-force way.

Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
net/core/pktgen.c | 144 +++++++++++++++---------------------------------------
1 file changed, 39 insertions(+), 105 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index f9883139e311..e335daa40211 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -831,6 +831,35 @@ static ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev)
return i;
}

+static __u32 pktgen_read_flag(const char *f, bool *disable)
+{
+ __u32 i;
+
+ if (f[0] == '!') {
+ *disable = true;
+ f++;
+ }
+
+ for (i = 0; i < NR_PKT_FLAGS; i++) {
+ if (!IS_ENABLED(CONFIG_XFRM) && i == IPSEC_SHIFT)
+ continue;
+
+ /* allow only disabling ipv6 flag */
+ if (!*disable && i == IPV6_SHIFT)
+ continue;
+
+ if (strcmp(f, pkt_flag_names[i]) == 0)
+ return 1 << i;
+ }
+
+ if (strcmp(f, "FLOW_RND") == 0) {
+ *disable = !*disable;
+ return F_FLOW_SEQ;
+ }
+
+ return 0;
+}
+
static ssize_t pktgen_if_write(struct file *file,
const char __user * user_buffer, size_t count,
loff_t * offset)
@@ -1188,7 +1217,10 @@ static ssize_t pktgen_if_write(struct file *file,
return count;
}
if (!strcmp(name, "flag")) {
+ __u32 flag;
char f[32];
+ bool disable = false;
+
memset(f, 0, 32);
len = strn_len(&user_buffer[i], sizeof(f) - 1);
if (len < 0)
@@ -1197,113 +1229,15 @@ static ssize_t pktgen_if_write(struct file *file,
if (copy_from_user(f, &user_buffer[i], len))
return -EFAULT;
i += len;
- if (strcmp(f, "IPSRC_RND") == 0)
- pkt_dev->flags |= F_IPSRC_RND;
-
- else if (strcmp(f, "!IPSRC_RND") == 0)
- pkt_dev->flags &= ~F_IPSRC_RND;
-
- else if (strcmp(f, "TXSIZE_RND") == 0)
- pkt_dev->flags |= F_TXSIZE_RND;
-
- else if (strcmp(f, "!TXSIZE_RND") == 0)
- pkt_dev->flags &= ~F_TXSIZE_RND;
-
- else if (strcmp(f, "IPDST_RND") == 0)
- pkt_dev->flags |= F_IPDST_RND;
-
- else if (strcmp(f, "!IPDST_RND") == 0)
- pkt_dev->flags &= ~F_IPDST_RND;
-
- else if (strcmp(f, "UDPSRC_RND") == 0)
- pkt_dev->flags |= F_UDPSRC_RND;
-
- else if (strcmp(f, "!UDPSRC_RND") == 0)
- pkt_dev->flags &= ~F_UDPSRC_RND;
-
- else if (strcmp(f, "UDPDST_RND") == 0)
- pkt_dev->flags |= F_UDPDST_RND;
-
- else if (strcmp(f, "!UDPDST_RND") == 0)
- pkt_dev->flags &= ~F_UDPDST_RND;
-
- else if (strcmp(f, "MACSRC_RND") == 0)
- pkt_dev->flags |= F_MACSRC_RND;
-
- else if (strcmp(f, "!MACSRC_RND") == 0)
- pkt_dev->flags &= ~F_MACSRC_RND;

- else if (strcmp(f, "MACDST_RND") == 0)
- pkt_dev->flags |= F_MACDST_RND;
+ flag = pktgen_read_flag(f, &disable);

- else if (strcmp(f, "!MACDST_RND") == 0)
- pkt_dev->flags &= ~F_MACDST_RND;
-
- else if (strcmp(f, "MPLS_RND") == 0)
- pkt_dev->flags |= F_MPLS_RND;
-
- else if (strcmp(f, "!MPLS_RND") == 0)
- pkt_dev->flags &= ~F_MPLS_RND;
-
- else if (strcmp(f, "VID_RND") == 0)
- pkt_dev->flags |= F_VID_RND;
-
- else if (strcmp(f, "!VID_RND") == 0)
- pkt_dev->flags &= ~F_VID_RND;
-
- else if (strcmp(f, "SVID_RND") == 0)
- pkt_dev->flags |= F_SVID_RND;
-
- else if (strcmp(f, "!SVID_RND") == 0)
- pkt_dev->flags &= ~F_SVID_RND;
-
- else if (strcmp(f, "FLOW_SEQ") == 0 || strcmp(f, "!FLOW_RND") == 0)
- pkt_dev->flags |= F_FLOW_SEQ;
-
- else if (strcmp(f, "FLOW_RND") == 0 || strcmp(f, "!FLOW_SEQ") == 0)
- pkt_dev->flags &= ~F_FLOW_SEQ;
-
- else if (strcmp(f, "QUEUE_MAP_RND") == 0)
- pkt_dev->flags |= F_QUEUE_MAP_RND;
-
- else if (strcmp(f, "!QUEUE_MAP_RND") == 0)
- pkt_dev->flags &= ~F_QUEUE_MAP_RND;
-
- else if (strcmp(f, "QUEUE_MAP_CPU") == 0)
- pkt_dev->flags |= F_QUEUE_MAP_CPU;
-
- else if (strcmp(f, "!QUEUE_MAP_CPU") == 0)
- pkt_dev->flags &= ~F_QUEUE_MAP_CPU;
-#ifdef CONFIG_XFRM
- else if (strcmp(f, "IPSEC") == 0)
- pkt_dev->flags |= F_IPSEC;
-
- else if (strcmp(f, "!IPSEC") == 0)
- pkt_dev->flags &= ~F_IPSEC;
-#endif
-
- else if (strcmp(f, "!IPV6") == 0)
- pkt_dev->flags &= ~F_IPV6;
-
- else if (strcmp(f, "NODE_ALLOC") == 0)
- pkt_dev->flags |= F_NODE;
-
- else if (strcmp(f, "!NODE_ALLOC") == 0)
- pkt_dev->flags &= ~F_NODE;
-
- else if (strcmp(f, "UDPCSUM") == 0)
- pkt_dev->flags |= F_UDPCSUM;
-
- else if (strcmp(f, "!UDPCSUM") == 0)
- pkt_dev->flags &= ~F_UDPCSUM;
-
- else if (strcmp(f, "NO_TIMESTAMP") == 0)
- pkt_dev->flags |= F_NO_TIMESTAMP;
-
- else if (strcmp(f, "!NO_TIMESTAMP") == 0)
- pkt_dev->flags &= ~F_NO_TIMESTAMP;
-
- else {
+ if (flag) {
+ if (disable)
+ pkt_dev->flags &= ~flag;
+ else
+ pkt_dev->flags |= flag;
+ } else {
sprintf(pg_result,
"Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
f,
--
2.13.6