@@ -1096,45 +1096,30 @@ static void append_release(char *buf)
scnprintf(buf, MAX_PRINT_CHUNK, "%s,", release);
}
-static void send_msg_fragmented(struct netconsole_target *nt,
- const char *msg,
- int msg_len,
- int release_len)
+static void send_fragmented_body(struct netconsole_target *nt, char *buf,
+ const char *msgbody, int header_len,
+ int msgbody_len)
{
- const char *header, *msgbody, *userdata;
- int header_len, msgbody_len, body_len;
- static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */
- int offset = 0, userdata_len = 0;
+ const char *userdata = NULL;
+ int body_len, offset = 0;
+ int userdata_len = 0;
#ifdef CONFIG_NETCONSOLE_DYNAMIC
userdata = nt->userdata_complete;
userdata_len = nt->userdata_length;
#endif
- /* need to insert extra header fields, detect header and msgbody */
- header = msg;
- msgbody = memchr(msg, ';', msg_len);
- if (WARN_ON_ONCE(!msgbody))
- return;
-
- header_len = msgbody - header;
- msgbody_len = msg_len - header_len - 1;
- msgbody++;
-
- /*
- * Transfer multiple chunks with the following extra header.
- * "ncfrag=<byte-offset>/<total-bytes>"
+ /* body_len represents the number of bytes that will be sent. This is
+ * bigger than MAX_PRINT_CHUNK, thus, it will be split in multiple
+ * packets
*/
- if (release_len)
- append_release(buf);
-
- /* Copy the header into the buffer */
- memcpy(buf + release_len, header, header_len);
- header_len += release_len;
-
body_len = msgbody_len + userdata_len;
- /* for now on, the header will be persisted, and the msgbody
- * will be replaced
+
+ /* In each iteration of the while loop below, we send a packet
+ * containing the header and a portion of the body. The body is
+ * composed of two parts: msgbody and userdata. We keep track of how
+ * many bytes have been sent so far using the offset variable, which
+ * ranges from 0 to the total length of the body.
*/
while (offset < body_len) {
int this_header = header_len;
@@ -1143,7 +1128,7 @@ static void send_msg_fragmented(struct netconsole_target *nt,
int this_chunk = 0;
this_header += scnprintf(buf + this_header,
- sizeof(buf) - this_header,
+ MAX_PRINT_CHUNK - this_header,
",ncfrag=%d/%d;", offset,
body_len);
@@ -1193,6 +1178,41 @@ static void send_msg_fragmented(struct netconsole_target *nt,
}
}
+static void send_msg_fragmented(struct netconsole_target *nt,
+ const char *msg,
+ int msg_len,
+ int release_len)
+{
+ static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */
+ int header_len, msgbody_len;
+ const char *msgbody;
+
+ /* need to insert extra header fields, detect header and msgbody */
+ msgbody = memchr(msg, ';', msg_len);
+ if (WARN_ON_ONCE(!msgbody))
+ return;
+
+ header_len = msgbody - msg;
+ msgbody_len = msg_len - header_len - 1;
+ msgbody++;
+
+ /*
+ * Transfer multiple chunks with the following extra header.
+ * "ncfrag=<byte-offset>/<total-bytes>"
+ */
+ if (release_len)
+ append_release(buf);
+
+ /* Copy the header into the buffer */
+ memcpy(buf + release_len, msg, header_len);
+ header_len += release_len;
+
+ /* for now on, the header will be persisted, and the msgbody
+ * will be replaced
+ */
+ send_fragmented_body(nt, buf, msgbody, header_len, msgbody_len);
+}
+
/**
* send_ext_msg_udp - send extended log message to target
* @nt: target to send message to
Refactor the send_msg_fragmented() function by extracting the logic for sending the message body into a new function called send_fragmented_body(). Now, send_msg_fragmented() handles appending the release and header, and then delegates the task of breaking up the body and sending the fragments to send_fragmented_body(). This is the final flow now: When send_ext_msg_udp() is called to send a message, it will: - call send_msg_no_fragmentation() if no fragmentation is needed or - call send_msg_fragmented() if fragmentation is needed * send_msg_fragmented() appends the header to the buffer, which is be persisted until the function returns * call send_fragmented_body() to iterate and populate the body of the message. It will not touch the header, and it will only replace the body, writing the msgbody and/or userdata. Also add some comment to make the code easier to review. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> --- drivers/net/netconsole.c | 82 +++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 31 deletions(-)