pktgen: Automate flag enumeration for unknown flag handling

When specifying an unknown flag, it will print all available flags.
Currently, these flags are provided as fixed strings, which requires
manual updates when flags change. Replacing it with automated flag
enumeration.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Link: https://lore.kernel.org/r/20230920125658.46978-1-liangchen.linux@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index f56b8d69701475683561032d992c97585320af63..48306a101fd9f2408192e157357aad7fe6ef714b 100644 (file)
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1318,9 +1318,10 @@ static ssize_t pktgen_if_write(struct file *file,
                return count;
        }
        if (!strcmp(name, "flag")) {
+               bool disable = false;
                __u32 flag;
                char f[32];
-               bool disable = false;
+               char *end;
 
                memset(f, 0, 32);
                len = strn_len(&user_buffer[i], sizeof(f) - 1);
@@ -1332,28 +1333,33 @@ static ssize_t pktgen_if_write(struct file *file,
                i += len;
 
                flag = pktgen_read_flag(f, &disable);
-
                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,
-                               "IPSRC_RND, IPDST_RND, UDPSRC_RND, UDPDST_RND, "
-                               "MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, "
-                               "MPLS_RND, VID_RND, SVID_RND, FLOW_SEQ, "
-                               "QUEUE_MAP_RND, QUEUE_MAP_CPU, UDPCSUM, "
-                               "NO_TIMESTAMP, "
-#ifdef CONFIG_XFRM
-                               "IPSEC, "
-#endif
-                               "NODE_ALLOC\n");
+
+                       sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
                        return count;
                }
-               sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
+
+               /* Unknown flag */
+               end = pkt_dev->result + sizeof(pkt_dev->result);
+               pg_result += sprintf(pg_result,
+                       "Flag -:%s:- unknown\n"
+                       "Available flags, (prepend ! to un-set flag):\n", f);
+
+               for (int n = 0; n < NR_PKT_FLAGS && pg_result < end; n++) {
+                       if (!IS_ENABLED(CONFIG_XFRM) && n == IPSEC_SHIFT)
+                               continue;
+                       pg_result += snprintf(pg_result, end - pg_result,
+                                             "%s, ", pkt_flag_names[n]);
+               }
+               if (!WARN_ON_ONCE(pg_result >= end)) {
+                       /* Remove the comma and whitespace at the end */
+                       *(pg_result - 2) = '\0';
+               }
+
                return count;
        }
        if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) {