Make tmpfs size configurable

README.md

@@ -109,8 +109,8 @@ Options:
  --log|-l [val]
 	Log file (default: stderr)
  --time_limit|-t [val]
+	Maximum time that a jail can exist, in seconds (default: 600)
  --daemon|-d
-	Daemonize after start? (default: false)
  --verbose|-v
 	Verbose output (default: false)
  --keep_env|-e
@@ -167,4 +167,6 @@ Options:
 	List of mountpoints to be mounted as RW/tmpfs inside the container. Can be specified multiple times. Supports 'dest' syntax. (default: none)
  --iface|-I [val]
 	Interface which will be cloned (MACVTAP) and put inside the subprocess' namespace
+ --tmpfs_size [val]
+	Number of bytes to allocate for tmpfsmounts in bytes (default: 4194304)
 ```

cmdline.c

@@ -86,13 +86,15 @@ void cmdlineLogParams(struct nsjconf_t *nsjconf)
 	    ("Jail parameters: hostname:'%s', chroot:'%s', process:'%s', port:%d, "
 	     "max_conns_per_ip:%u, uid:%u, gid:%u, time_limit:%ld, personality:%#lx, daemonize:%s, "
 	     "clone_newnet:%s, clone_newuser:%s, clone_newns:%s, clone_newpid:%s, "
-	     "clone_newipc:%s, clonew_newuts:%s, apply_sandbox:%s, keep_caps:%s",
+	     "clone_newipc:%s, clonew_newuts:%s, apply_sandbox:%s, keep_caps:%s, "
+	     "tmpfs_size:%u",
 	     nsjconf->hostname, nsjconf->chroot, nsjconf->argv[0], nsjconf->port,
 	     nsjconf->max_conns_per_ip, nsjconf->uid, nsjconf->gid, nsjconf->tlimit,
 	     nsjconf->personality, logYesNo(nsjconf->daemonize), logYesNo(nsjconf->clone_newnet),
 	     logYesNo(nsjconf->clone_newuser), logYesNo(nsjconf->clone_newns),
 	     logYesNo(nsjconf->clone_newpid), logYesNo(nsjconf->clone_newipc),
-	     logYesNo(nsjconf->clone_newuts), logYesNo(nsjconf->apply_sandbox), logYesNo(nsjconf->keep_caps));
+	     logYesNo(nsjconf->clone_newuts), logYesNo(nsjconf->apply_sandbox),
+	     logYesNo(nsjconf->keep_caps), nsjconf->tmpfs_size);
 
 	struct constchar_t *p;
 	LIST_FOREACH(p, &nsjconf->robindmountpts, pointers) {
@@ -180,6 +182,7 @@ bool cmdlineParse(int argc, char *argv[], struct nsjconf_t * nsjconf)
 		.initial_uid = getuid(),
 		.initial_gid = getgid(),
 		.max_conns_per_ip = 0,
+		.tmpfs_size = 4*1024*1024,
 	};
 	/*  *INDENT-OFF* */
 
@@ -236,6 +239,7 @@ bool cmdlineParse(int argc, char *argv[], struct nsjconf_t * nsjconf)
 		{{"bindmount", required_argument, NULL, 'B'}, "List of mountpoints to be mounted --bind (rw) inside the container. Can be specified multiple times. Supports 'source' syntax, or 'source:dest'. (default: none)"},
 		{{"tmpfsmount", required_argument, NULL, 'T'}, "List of mountpoints to be mounted as RW/tmpfs inside the container. Can be specified multiple times. Supports 'dest' syntax. (default: none)"},
 		{{"iface", required_argument, NULL, 'I'}, "Interface which will be cloned (MACVTAP) and put inside the subprocess' namespace"},
+		{{"tmpfs_size", required_argument, NULL, 0x0506}, "Number of bytes to allocate for tmpfsmounts in bytes (default: 4194304)"},
 		{{0, 0, 0, 0}, NULL},
 	};
         /*  *INDENT-ON* */
@@ -264,6 +268,9 @@ bool cmdlineParse(int argc, char *argv[], struct nsjconf_t * nsjconf)
 		case 'i':
 			nsjconf->max_conns_per_ip = strtoul(optarg, NULL, 0);
 			break;
+		case 0x0506:
+			nsjconf->tmpfs_size = strtoul(optarg, NULL, 0);
+			break;
 		case 'u':
 			user = optarg;
 			break;

common.h

@@ -83,6 +83,7 @@ struct nsjconf_t {
 	uid_t initial_uid;
 	gid_t initial_gid;
 	unsigned int max_conns_per_ip;
+	unsigned int tmpfs_size;
 	 LIST_HEAD(pidslist, pids_t) pids;
 	 LIST_HEAD(rwbindmountptslist, constchar_t) rwbindmountpts;
 	 LIST_HEAD(robindmountptslist, constchar_t) robindmountpts;

contain.c

@@ -297,6 +297,8 @@ bool containMountFS(struct nsjconf_t * nsjconf)
 	/* It only makes sense with "--chroot /", so don't worry about errors */
 	umount2(destdir, MNT_DETACH);
 
+	char tmpfs_size[11+5];
+	snprintf(tmpfs_size, sizeof(tmpfs_size), "size=%u", nsjconf->tmpfs_size);
 	LIST_FOREACH(p, &nsjconf->tmpfsmountpts, pointers) {
 		if (strchr(p->value, ':') != NULL) {
 			PLOG_E("invalid tmpfs mount spec. source:dest format unsupported.");
@@ -308,7 +310,7 @@ bool containMountFS(struct nsjconf_t * nsjconf)
 			return false;
 		}
 		LOG_D("Mounting (tmpfs) '%s'", p->value);
-		if (mount(NULL, p->value, "tmpfs", 0, "size=4194304") == -1) {
+		if (mount(NULL, p->value, "tmpfs", 0, tmpfs_size) == -1) {
 			PLOG_E("mount('%s', 'tmpfs')", p->value);
 			return false;
 		}