instance.c

   1 #include <unistd.h>
   2
   3 #include "procd.h"
   4 #include "service.h"
   5 #include "instance.h"
   6
   7 enum {
   8         INSTANCE_ATTR_COMMAND,
   9         INSTANCE_ATTR_ENV,
  10         INSTANCE_ATTR_DATA,
  11         __INSTANCE_ATTR_MAX
  12 };
  13
  14 static const struct blobmsg_policy instance_attr[__INSTANCE_ATTR_MAX] = {
  15         [INSTANCE_ATTR_COMMAND] = { "command", BLOBMSG_TYPE_ARRAY },
  16         [INSTANCE_ATTR_ENV] = { "env", BLOBMSG_TYPE_TABLE },
  17         [INSTANCE_ATTR_DATA] = { "data", BLOBMSG_TYPE_TABLE },
  18 };
  19
  20 static void
  21 instance_run(struct service_instance *in)
  22 {
  23         struct blobmsg_list_node *var;
  24         struct blob_attr *cur;
  25         char **argv;
  26         int argc = 1; /* NULL terminated */
  27         int rem;
  28
  29         blobmsg_for_each_attr(cur, in->command, rem)
  30                 argc++;
  31
  32         blobmsg_list_for_each(&in->env, var)
  33                 putenv(blobmsg_data(var->data));
  34
  35         argv = alloca(sizeof(char *) * argc);
  36         argc = 0;
  37
  38         blobmsg_for_each_attr(cur, in->command, rem)
  39                 argv[argc++] = blobmsg_data(cur);
  40
  41         argv[argc] = NULL;
  42         execvp(argv[0], argv);
  43         exit(127);
  44 }
  45
  46 void
  47 instance_start(struct service_instance *in)
  48 {
  49         int pid;
  50
  51         if (in->proc.pending)
  52                 return;
  53
  54         in->restart = false;
  55         if (!in->valid)
  56                 return;
  57
  58         pid = fork();
  59         if (pid < 0)
  60                 return;
  61
  62         if (!pid) {
  63                 instance_run(in);
  64                 return;
  65         }
  66
  67         in->proc.pid = pid;
  68         uloop_process_add(&in->proc);
  69 }
  70
  71 static void
  72 instance_timeout(struct uloop_timeout *t)
  73 {
  74         struct service_instance *in;
  75
  76         in = container_of(t, struct service_instance, timeout);
  77         kill(in->proc.pid, SIGKILL);
  78         uloop_process_delete(&in->proc);
  79         in->proc.cb(&in->proc, -1);
  80 }
  81
  82 static void
  83 instance_exit(struct uloop_process *p, int ret)
  84 {
  85         struct service_instance *in;
  86
  87         in = container_of(p, struct service_instance, proc);
  88         uloop_timeout_cancel(&in->timeout);
  89         if (in->restart)
  90                 instance_start(in);
  91 }
  92
  93 void
  94 instance_stop(struct service_instance *in, bool restart)
  95 {
  96         if (!in->proc.pending)
  97                 return;
  98
  99         kill(in->proc.pid, SIGTERM);
 100 }
 101
 102 static bool
 103 instance_config_changed(struct service_instance *in, struct service_instance *in_new)
 104 {
 105         if (!in->valid)
 106                 return true;
 107
 108         if (!blob_attr_equal(in->command, in_new->command))
 109                 return true;
 110
 111         if (!blobmsg_list_equal(&in->env, &in_new->env))
 112                 return true;
 113
 114         if (!blobmsg_list_equal(&in->data, &in_new->data))
 115                 return true;
 116
 117         return false;
 118 }
 119
 120 static bool
 121 instance_config_parse(struct service_instance *in)
 122 {
 123         struct blob_attr *tb[__INSTANCE_ATTR_MAX];
 124         struct blob_attr *cur, *cur2;
 125         int argc = 0;
 126         int rem;
 127
 128         blobmsg_parse(instance_attr, __INSTANCE_ATTR_MAX, tb,
 129                 blobmsg_data(in->config), blobmsg_data_len(in->config));
 130
 131         cur = tb[INSTANCE_ATTR_COMMAND];
 132         if (!cur)
 133                 return false;
 134
 135         if (!blobmsg_check_attr_list(cur, BLOBMSG_TYPE_STRING))
 136                 return false;
 137
 138         blobmsg_for_each_attr(cur2, cur, rem) {
 139                 argc++;
 140                 break;
 141         }
 142         if (!argc)
 143                 return false;
 144
 145         in->command = cur;
 146
 147         if ((cur = tb[INSTANCE_ATTR_ENV])) {
 148                 if (!blobmsg_check_attr_list(cur, BLOBMSG_TYPE_STRING))
 149                         return false;
 150                 blobmsg_list_fill(&in->env, blobmsg_data(cur), blobmsg_data_len(cur));
 151         }
 152
 153         if ((cur = tb[INSTANCE_ATTR_DATA])) {
 154                 if (!blobmsg_check_attr_list(cur, BLOBMSG_TYPE_STRING))
 155                         return false;
 156                 blobmsg_list_fill(&in->data, blobmsg_data(cur), blobmsg_data_len(cur));
 157         }
 158
 159         return true;
 160 }
 161
 162 static void
 163 instance_config_cleanup(struct service_instance *in)
 164 {
 165         blobmsg_list_free(&in->env);
 166         blobmsg_list_free(&in->data);
 167 }
 168
 169 static void
 170 instance_config_move(struct service_instance *in, struct service_instance *in_src)
 171 {
 172         instance_config_cleanup(in);
 173         blobmsg_list_move(&in->env, &in_src->env);
 174         blobmsg_list_move(&in->data, &in_src->data);
 175         in->command = in_src->command;
 176 }
 177
 178 bool
 179 instance_update(struct service_instance *in, struct service_instance *in_new)
 180 {
 181         bool changed = instance_config_changed(in, in_new);
 182
 183         in->config = in_new->config;
 184         if (!changed)
 185                 return false;
 186
 187         in->restart = true;
 188         instance_stop(in, true);
 189         instance_config_move(in, in_new);
 190         return true;
 191 }
 192
 193 void
 194 instance_free(struct service_instance *in)
 195 {
 196         uloop_process_delete(&in->proc);
 197         uloop_timeout_cancel(&in->timeout);
 198         instance_config_cleanup(in);
 199         free(in);
 200 }
 201
 202 void
 203 instance_init(struct service_instance *in, struct blob_attr *config)
 204 {
 205         in->config = config;
 206         in->timeout.cb = instance_timeout;
 207         in->proc.cb = instance_exit;
 208
 209         blobmsg_list_simple_init(&in->env);
 210         blobmsg_list_simple_init(&in->data);
 211         in->valid = instance_config_parse(in);
 212 }