add unix domain socket support

sysmon.c

@@ -14,20 +14,24 @@
 #include <sys/time.h>
 #include <sys/statvfs.h>
 #include <math.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 
 #include "ini.h"
-
+#ifndef PREFIX
+#define PREFIX
+#endif
 #define DEFAULT_CONF_FILE (PREFIX "/etc/sysmond.conf")
 #define MODULE_NAME "sysmon"
-// #define DEFAULT_INPUT "/sys/class/hwmon/hwmon2/device/in3_input"
 #define NET_INF_STAT_PT "/sys/class/net/%s/statistics/%s"
 
-#define LOG_INIT(m) do { \
+#define LOG_INIT(m)                                              \
+    do                                                           \
+    {                                                            \
         setlogmask(LOG_UPTO(LOG_NOTICE));                        \
         openlog((m), LOG_CONS | LOG_PID | LOG_NDELAY, LOG_USER); \
     } while (0)
 
-
 #define M_LOG(m, a, ...) syslog((LOG_NOTICE), m "_log@[%s: %d]: " a "\n", __FILE__, \
                                 __LINE__, ##__VA_ARGS__)
 
@@ -67,6 +71,7 @@
 #define MAX_BUF 256
 #define EQU(a, b) (strncmp(a, b, MAX_BUF) == 0)
 #define MAX_NETWORK_INF 8
+
 typedef struct
 {
     char bat_in[MAX_BUF];
@@ -86,7 +91,8 @@ typedef struct
     uint16_t gpu;
 } sys_temp_t;
 
-typedef struct {
+typedef struct
+{
     char name[32];
     unsigned long tx;
     unsigned long rx;
@@ -94,7 +100,8 @@ typedef struct {
     float tx_rate;
 } sys_net_inf_t;
 
-typedef struct {
+typedef struct
+{
     uint8_t n_intf;
     /*Monitor up to 8 interfaces*/
     sys_net_inf_t interfaces[MAX_NETWORK_INF];
@@ -107,7 +114,8 @@ typedef struct
     float percent;
 } sys_cpu_t;
 
-typedef struct {
+typedef struct
+{
     char mount_path[MAX_BUF];
     unsigned long d_total;
     unsigned long d_free;
@@ -124,7 +132,8 @@ typedef struct
     unsigned long m_swap_free;
 } sys_mem_t;
 
-typedef struct {
+typedef struct
+{
     char conf_file[MAX_BUF];
     char data_file_out[MAX_BUF];
     sys_bat_t bat_stat;
@@ -167,7 +176,9 @@ static void map(app_data_t* opt)
         return;
     }
     float result = 101 - (101 / pow(1 + pow(1.33 * (volt - opt->bat_stat.min_voltage) /
-                                          (opt->bat_stat.max_voltage - opt->bat_stat.min_voltage), 4.5), 3));
+                                                (opt->bat_stat.max_voltage - opt->bat_stat.min_voltage),
+                                            4.5),
+                                    3));
     if (result > 100.0)
         result = 100.0;
 
@@ -198,6 +209,27 @@ static int guard_write(int fd, void* buffer, size_t size)
     return n;
 }
 
+static int open_unix_socket(char *path)
+{
+    struct sockaddr_un address;
+    address.sun_family = AF_UNIX;
+    (void)memset(address.sun_path, 0, sizeof(address.sun_path));
+    (void)memcpy(address.sun_path, path, sizeof(address.sun_path));
+    int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (fd == -1)
+    {
+        M_ERROR(MODULE_NAME, "Unable to create Unix domain socket: %s", strerror(errno));
+        return -1;
+    }
+    if (connect(fd, (struct sockaddr *)(&address), sizeof(address)) == -1)
+    {
+        M_ERROR(MODULE_NAME, "Unable to connect to socket '%s': %s", address.sun_path, strerror(errno));
+        return -1;
+    }
+    M_LOG(MODULE_NAME, "Socket %s is created successfully", path);
+    return fd;
+}
+
 static int read_line(int fd, char *buf, int size)
 {
     int i = 0;
@@ -265,7 +297,8 @@ static int read_cpu_info(app_data_t* opts)
             while (token != NULL)
             {
                 token = strtok(NULL, d);
-                if(token!=NULL){
+                if (token != NULL)
+                {
                     sum += strtoul(token, NULL, 10);
                     if (j == 3)
                         idle = strtoul(token, NULL, 10);
@@ -303,7 +336,8 @@ static int read_mem_info(app_data_t* opts)
         M_ERROR(MODULE_NAME, "Unable to open meminfo: %s", strerror(errno));
         return -1;
     }
-    for (int i = 0; i < 7; i++) {
+    for (int i = 0; i < 7; i++)
+    {
         ret = read_line(fd, buf, MAX_BUF);
         token = strtok(buf, d);
         token = strtok(NULL, d);
@@ -317,7 +351,8 @@ static int read_mem_info(app_data_t* opts)
         }
         if (i == 4)
         {
-            for (int j = 0; j < 9; j++) {
+            for (int j = 0; j < 9; j++)
+            {
                 ret = read_line(fd, buf, MAX_BUF);
                 // skip 10 line
             }
@@ -333,7 +368,6 @@ static int read_mem_info(app_data_t* opts)
     (void)ret;
     (void)close(fd);
 
-    
     /*printf("total: %d used: %d, free: %d buffer/cache: %d, available: %d \n",
         opts->mem.m_total / 1024,
         (opts->mem.m_total - opts->mem.m_free - opts->mem.m_buffer-opts->mem.m_cache)/1024,
@@ -446,15 +480,32 @@ static int read_disk_usage(app_data_t* opts)
 
 static int log_to_file(app_data_t *opts)
 {
-    int ret,fd;
+    int ret, fd = -1, use_stdout = 0;
     char out_buf[1024];
     char net_buf[MAX_BUF];
+    (void)memset(out_buf, 0, sizeof(out_buf));
+    (void)memset(net_buf, 0, sizeof(net_buf));
     if (opts->data_file_out[0] == '\0')
     {
         return 0;
     }
+    // check if we use stdout
+    if (strncmp(opts->data_file_out, "stdout", 6) == 0)
+    {
+        // out put to stdout
+        use_stdout = 1;
+    }
+    else if (strncmp(opts->data_file_out, "sock:", 5) == 0)
+    {
+        // Unix domain socket
+        fd = open_unix_socket(opts->data_file_out + 5);
+    }
+    else
+    {
+        // open regular file
         fd = open(opts->data_file_out, O_CREAT | O_WRONLY | O_APPEND | O_NONBLOCK, 0644);
-    if(fd < 0)
+    }
+    if (fd < 0 && !use_stdout)
     {
         M_ERROR(MODULE_NAME, "Unable to open output file: %s", strerror(errno));
         return -1;
@@ -463,7 +514,8 @@ static int log_to_file(app_data_t* opts)
     char *ptr = buf;
     // CPU
     size_t len = 0;
-    for (int i = 0; i < opts->n_cpus; i++) {
+    for (int i = 0; i < opts->n_cpus; i++)
+    {
         if (MAX_BUF - len - 1 <= 0)
         {
             break;
@@ -477,7 +529,8 @@ static int log_to_file(app_data_t* opts)
     // NET
     len = 0;
     ptr = net_buf;
-    for (int i = 0; i < opts->net.n_intf; i++) {
+    for (int i = 0; i < opts->net.n_intf; i++)
+    {
         if (MAX_BUF - len - 1 < strlen(JSON_NET_FMT))
         {
             break;
@@ -487,8 +540,7 @@ static int log_to_file(app_data_t* opts)
                  opts->net.interfaces[i].rx,
                  opts->net.interfaces[i].tx,
                  opts->net.interfaces[i].rx_rate,
-            opts->net.interfaces[i].tx_rate
+                 opts->net.interfaces[i].tx_rate);
-            );
         len = strlen(net_buf);
         ptr = net_buf + len;
     }
@@ -515,8 +567,15 @@ static int log_to_file(app_data_t* opts)
              opts->mem.m_swap_free,
              opts->disk.d_total,
              opts->disk.d_free,
-        net_buf
+             net_buf);
-        );
+    out_buf[strlen(out_buf)] = '\n';
+    ret = 0;
+    if (use_stdout)
+    {
+        printf("%s", out_buf);
+    }
+    else
+    {
         ret = guard_write(fd, out_buf, strlen(out_buf));
         if (ret <= 0)
         {
@@ -528,11 +587,8 @@ static int log_to_file(app_data_t* opts)
             M_ERROR(MODULE_NAME, "Unable to write all battery info to output file");
             ret = -1;
         }
-    else
-    {
-        // M_LOG(MODULE_NAME, "written %d bytes to file: %s", strlen(out_buf), opts->data_file_out);
-        ret = 0;
     }
+    if (fd > 0)
         (void)close(fd);
     return ret;
 }
@@ -646,7 +702,6 @@ static int load_config(app_data_t* opts)
     opts->bat_stat.percent = 0.0;
     opts->power_off_percent = 1;
 
-    
     (void)memset(&opts->mem, '\0', sizeof(opts->mem));
     (void)memset(&opts->temp, '\0', sizeof(opts->temp));
     (void)memset(&opts->net, '\0', sizeof(opts->net));

sysmond.conf

@@ -23,6 +23,7 @@ disk_mount_point = /
 # the system will be shutdown after n count down
 power_off_count_down = 10
 # the system will bet shutdown if the battery voltage percent is below this value
+# after `power_off_count_down` time
 power_off_percent = 3
 
 cpu_temperature_input=/sys/devices/virtual/thermal/thermal_zone1/temp
@@ -30,4 +31,9 @@ cpu_temperature_input=/sys/devices/virtual/thermal/thermal_zone1/temp
 gpu_temperature_input=/sys/devices/virtual/thermal/thermal_zone2/temp
 
 # output system info to file
-data_file_out = /var/jarvis:fbf070ddea3ea90d07f456540b405d302554ec82
+# The output file may be: stdout, a regular file or name pipe, or a unix domain socket
+# To print JSON data records to stdout use
+# data_file_out = stdout
+# To send data via unix domain socket use
+# data_file_out = sock:/path/to/socket/file
+data_file_out = sock:/var/sysmond.log