From cd89f0b340764e73de76f5297217caf61b3d3283 Mon Sep 17 00:00:00 2001
From: Oliver Smith <osmith@sysmocom.de>
Date: Tue, 13 Dec 2022 16:05:00 +0100
Subject: [PATCH] gps2udp: Add a label, timestamp and mac address to each
 report

Rebase of 0001-gps2udp-Add-a-label-timestamp-and-mac-address-to-eac.patch
we have been carrying:

From 19a55075d4e60e07d03d49937cd2a4d9239d00a4 Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <hfreyther@sysmocom.de>
Date: Fri, 22 Aug 2014 09:55:19 +0200
Subject: [PATCH] gps2udp: Add a label, timestamp and mac address to each
 report
---
 clients/gps2udp.c | 61 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 59 insertions(+), 2 deletions(-)

diff --git a/clients/gps2udp.c b/clients/gps2udp.c
index 2d9c6033d..d27814f24 100644
--- a/clients/gps2udp.c
+++ b/clients/gps2udp.c
@@ -22,6 +22,7 @@
        #include <getopt.h>   // for getopt_long()
 #endif
 #include <netdb.h>        /* for gethostbyname() */
+#include <net/if.h>
 #include <netinet/in.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -29,6 +30,7 @@
 // do not use strsep() it is not POSIX
 #include <string.h>      /* for strlcpy(), strtok(), etc. */
 #include <strings.h>
+#include <sys/ioctl.h>
 #include <sys/select.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ -60,6 +62,9 @@ static unsigned int flags;
 static unsigned int debug = 0;
 static bool aisonly = false;
 static bool tpvonly = false;
+static const char *label;
+static const char *mac;
+static char *mac_string;
 
 // return local time hh:mm:ss
 static char* time2string(void)
@@ -82,6 +87,7 @@ static char* time2string(void)
 
 static int send_udp(char *nmeastring, size_t ind)
 {
+    char output[1024];
     char message[MAX_PACKET_LENGTH];
     char *buffer;
     int  channel;
@@ -108,6 +114,16 @@ static int send_udp(char *nmeastring, size_t ind)
     buffer[ind] = '\n'; ind++;
     buffer[ind] = '\0';
 
+    /* copy once more for the label */
+    if (label)
+        snprintf(output, 1024, "%s,%llu,%s,%s",
+                label, (unsigned long long ) time(NULL), mac_string, buffer);
+    else
+        snprintf(output, 1024, "%s", buffer);
+
+    output[1023] = '\0';
+    ind = strlen(output);
+
     if (0 == (flags & WATCH_JSON) &&
         '{' == buffer[0]) {
         // do not send JSON when not configured to do so
@@ -129,7 +145,7 @@ static int send_udp(char *nmeastring, size_t ind)
     // send message on udp channel
     for (channel=0; channel < udpchannel; channel ++) {
         ssize_t status = sendto(sock[channel],
-                                buffer,
+                                output,
                                 ind,
                                 0,
                                 (struct sockaddr *)&remote[channel],
@@ -225,6 +241,8 @@ static void usage(void)
                   "  -c COUNT            Exit after count packets.\n"
                   "  -d [0-2]            1 display sent packets, "
                   "2 display ignored packets.\n"
+                  "  -l [NAME]           A label to be used for the output\n"
+                  "  -m [IF_NAME]        The interface to extract the mac from\n"
                   "  -h                  Show this help.\n"
                   "  -j                  Feed JSON.\n"
                   "  -n                  Feed NMEA.\n"
@@ -421,7 +439,7 @@ int main(int argc, char **argv)
     bool daemonize = false;
     long count = -1;
     char *udphostport[MAX_UDP_DEST];
-    const char *optstring = "?abc:d:hjntu:V";
+    const char *optstring = "?abc:d:l:m:hjntu:V";
 #ifdef HAVE_GETOPT_LONG
     int option_index = 0;
     static struct option long_options[] = {
@@ -478,6 +496,12 @@ int main(int argc, char **argv)
             if (0 < debug)
                 (void)fprintf(stdout, "Debug %u selected\n", debug);
             break;
+        case 'l':
+            label = optarg;
+            break;
+        case 'm':
+            mac = optarg;
+            break;
         case 'j':
             if (0 < debug)
                 (void)fprintf(stdout, "JSON selected\n");
@@ -520,6 +544,39 @@ int main(int argc, char **argv)
         }
     }
 
+    if (label && !mac) {
+        fprintf(stderr, "Need to specify the ethernet device to find the mac.\n");
+        exit(EXIT_FAILURE);
+    }
+    if (mac && strlen(mac) >= IFNAMSIZ) {
+        fprintf(stderr, "Interface name is too long.\n");
+        exit(EXIT_FAILURE);
+    } else if (mac) {
+        struct ifreq addr = { };
+        int fd, rc;
+        fd = socket(AF_INET, SOCK_DGRAM, 0);
+        if (fd < 0) {
+            fprintf(stderr, "Failed to open socket.\n");
+            exit(EXIT_FAILURE);
+        }
+        memcpy(&addr.ifr_name, mac, strlen(mac));
+        rc = ioctl(fd, SIOCGIFHWADDR, &addr);
+        close(fd);
+        if (rc < 0) {
+            fprintf(stderr, "Failed to query address.\n");
+            exit(EXIT_FAILURE);
+        }
+        mac_string = malloc(40 * sizeof(char));
+        snprintf(mac_string, 40,
+                    "%.2X:%.2X:%.2X:%.2X:%.2X:%.2X",
+                    addr.ifr_hwaddr.sa_data[0] & 0xff,
+                    addr.ifr_hwaddr.sa_data[1] & 0xff,
+                    addr.ifr_hwaddr.sa_data[2] & 0xff,
+                    addr.ifr_hwaddr.sa_data[3] & 0xff,
+                    addr.ifr_hwaddr.sa_data[4] & 0xff,
+                    addr.ifr_hwaddr.sa_data[5] & 0xff);
+    }
+
     // Grok the server, port, and device.
     if (optind < argc) {
         gpsd_source_spec(argv[optind], &gpsd_source);
-- 
2.34.1