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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Shuah Khan , Simon Horman , Jonathan Corbet Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, gustavold@gmail.com, asantostc@gmail.com, calvin@wbinvd.org, kernel-team@meta.com X-Mailer: b4 0.15-dev-a6db3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2745; i=leitao@debian.org; h=from:subject:message-id; bh=dn83itIlZUWLQ+U+eA+BuY6G1TrO1GUvpGmFX9B58mE=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBpKa/FqDVOsFZ8329Lx8kfljFJl1ghgku9drY0/ AXGcDnSjzWJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaSmvxQAKCRA1o5Of/Hh3 bRTFD/0Tu3SmDZIjSP/ODQfN9yDeyLXcHnrAF9W8o4lc9Z5qBaMIegPzgfCChdgS4l0zwd2IwHD LD3CsR5N+YvzA30Thp+Zu8F7Q2Re3L+6ai1dieyBHutSl/V9LfSLR7WU8GVswYP+d5iETinR3jC hhhzf4d98d/0kd6pExSOKwsFlT19wEIH3T2Bad7IWqrnZALyLVQwzfkVEcJW7W0dmiClW+VdYid rVdeqld6a7zkqCrdHf6DZsZ/y7YUzgJsNi09EeqT3k+HABD/KQXvRsPKIJK1zSOwsrhhpKwOaFG JiDNBwUkmb7wCwPV+GkwkFCyb6jwMMR8qaL85HSE2QuazfTw1rrAFRI9V5kvGjCuvf1zrVcjrOd QlIYi8A1zHyl6Zk5dleTIzrdzHLogwj301mKRxgEFMtEBq6BzUBo1GNkIsFW1dAvYmZ8G9vF7+s Kdv99GHXtSx3FpdDJi11tcBG9ZVc30lFu9qQJ85JVCPeFteXYbMf9H9zQt/4ern0fmEB2OKDVBb JTnjaEZ6LnW6nm06keF2OWv1BTxSoUBIFG0Rss0jMdlOG+8QEsylTV2MqHocI2X3ABuqB0zKF89 UGyX96WZIHo4WpkIORZgwXMdsOTTXup0GSNZIsuMpsWpS5GsUkk9ejOhT+cc7l/GSWTwAlSL4Z+ PD3Ybkt+pdrnXMg== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D Add a new write-only configfs attribute "send_msg" to netconsole targets that allows sending arbitrary messages directly through netconsole. This feature enables users to send custom messages through netconsole without having to go through the kernel logging infrastructure. Messages can be sent by simply writing to: /sys/kernel/config/netconsole//send_msg The implementation: - Checks if the target is enabled before sending - Verifies the network interface is running - Handles both basic and extended message formats - Fragments large messages when needed for basic targets - Reuses existing send_msg_udp() and send_ext_msg_udp() functions Unfortunately this patch has two forward declaration, which is not ideal, but, moving send_msg_udp() functions earlier would cause too many changes, and this could be done in an idependent patch. Signed-off-by: Breno Leitao --- drivers/net/netconsole.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index dc3bd7c9b049..245ed2584bbb 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -1194,6 +1194,39 @@ static const struct config_item_type userdata_type = { .ct_owner = THIS_MODULE, }; +/* Forward declarations */ +static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg, + int msg_len); +static void send_msg_udp(struct netconsole_target *nt, const char *msg, + unsigned int len); + +static ssize_t send_msg_store(struct config_item *item, const char *buf, + size_t count) +{ + struct netconsole_target *nt = to_target(item); + ssize_t ret = -EINVAL; + unsigned long flags; + + mutex_lock(&dynamic_netconsole_mutex); + if (!nt->enabled) + goto out; + + if (!netif_running(nt->np.dev)) + goto out; + + spin_lock_irqsave(&target_list_lock, flags); + if (nt->extended) + send_ext_msg_udp(nt, buf, count); + else + send_msg_udp(nt, buf, count); + spin_unlock_irqrestore(&target_list_lock, flags); + + ret = count; +out: + mutex_unlock(&dynamic_netconsole_mutex); + + return ret; +} CONFIGFS_ATTR(, enabled); CONFIGFS_ATTR(, extended); CONFIGFS_ATTR(, dev_name); @@ -1205,6 +1238,7 @@ CONFIGFS_ATTR_RO(, local_mac); CONFIGFS_ATTR(, remote_mac); CONFIGFS_ATTR(, release); CONFIGFS_ATTR_RO(, transmit_errors); +CONFIGFS_ATTR_WO(, send_msg); static struct configfs_attribute *netconsole_target_attrs[] = { &attr_enabled, @@ -1218,6 +1252,7 @@ static struct configfs_attribute *netconsole_target_attrs[] = { &attr_local_mac, &attr_remote_mac, &attr_transmit_errors, + &attr_send_msg, NULL, }; -- 2.47.3