common/log_syslog.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Log to syslog.
   4  *
   5  * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
   6  */
   7
   8 #include <common.h>
   9 #include <log.h>
  10 #include <net.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 #define BUFFER_SIZE 480
  15
  16 static void append(char **buf, char *buf_end, const char *fmt, ...)
  17 {
  18         va_list args;
  19         size_t size = buf_end - *buf;
  20
  21         va_start(args, fmt);
  22         vsnprintf(*buf, size, fmt, args);
  23         va_end(args);
  24         *buf += strlen(*buf);
  25 }
  26
  27 static int log_syslog_emit(struct log_device *ldev, struct log_rec *rec)
  28 {
  29         int ret;
  30         int fmt = gd->log_fmt;
  31         char msg[BUFFER_SIZE];
  32         char *msg_end = msg + BUFFER_SIZE;
  33         char *ptr = msg;
  34         char *iphdr;
  35         char *log_msg;
  36         int eth_hdr_size;
  37         struct in_addr bcast_ip;
  38         static int processing_msg;
  39         unsigned int log_level;
  40         char *log_hostname;
  41
  42         /* Fend off messages from the network stack while writing a message */
  43         if (processing_msg)
  44                 return 0;
  45
  46         processing_msg = 1;
  47
  48         /* Setup packet buffers */
  49         net_init();
  50         /* Disable hardware and put it into the reset state */
  51         eth_halt();
  52         /* Set current device according to environment variables */
  53         eth_set_current();
  54         /* Get hardware ready for send and receive operations */
  55         ret = eth_init();
  56         if (ret < 0) {
  57                 eth_halt();
  58                 goto out;
  59         }
  60
  61         memset(msg, 0, BUFFER_SIZE);
  62
  63         /* Set ethernet header */
  64         eth_hdr_size = net_set_ether((uchar *)ptr, net_bcast_ethaddr, PROT_IP);
  65         ptr += eth_hdr_size;
  66         iphdr = ptr;
  67         ptr += IP_UDP_HDR_SIZE;
  68         log_msg = ptr;
  69
  70         /*
  71          * The syslog log levels defined in RFC 5424 match the U-Boot ones up to
  72          * level 7 (debug).
  73          */
  74         log_level = rec->level;
  75         if (log_level > 7)
  76                 log_level = 7;
  77         /* Leave high bits as 0 to write a 'kernel message' */
  78
  79         /* Write log message to buffer */
  80         append(&ptr, msg_end, "<%u>", log_level);
  81         log_hostname = env_get("log_hostname");
  82         if (log_hostname)
  83                 append(&ptr, msg_end, "%s ", log_hostname);
  84         append(&ptr, msg_end, "uboot: ");
  85         if (fmt & (1 << LOGF_LEVEL))
  86                 append(&ptr, msg_end, "%s.",
  87                        log_get_level_name(rec->level));
  88         if (fmt & (1 << LOGF_CAT))
  89                 append(&ptr, msg_end, "%s,",
  90                        log_get_cat_name(rec->cat));
  91         if (fmt & (1 << LOGF_FILE))
  92                 append(&ptr, msg_end, "%s:", rec->file);
  93         if (fmt & (1 << LOGF_LINE))
  94                 append(&ptr, msg_end, "%d-", rec->line);
  95         if (fmt & (1 << LOGF_FUNC))
  96                 append(&ptr, msg_end, "%s()", rec->func);
  97         if (fmt & (1 << LOGF_MSG))
  98                 append(&ptr, msg_end, "%s%s",
  99                        fmt != (1 << LOGF_MSG) ? " " : "", rec->msg);
 100         /* Consider trailing 0x00 */
 101         ptr++;
 102
 103         debug("log message: '%s'\n", log_msg);
 104
 105         /* Broadcast message */
 106         bcast_ip.s_addr = 0xFFFFFFFFL;
 107         net_set_udp_header((uchar *)iphdr, bcast_ip, 514, 514, ptr - log_msg);
 108         net_send_packet((uchar *)msg, ptr - msg);
 109
 110 out:
 111         processing_msg = 0;
 112         return ret;
 113 }
 114
 115 LOG_DRIVER(syslog) = {
 116         .name   = "syslog",
 117         .emit   = log_syslog_emit,
 118 };