path: root/src/util.c

#include "util.h"

#include <net/ethernet.h>
#include <netgraph.h>
#include <netgraph/ng_message.h>
#include <netgraph/ng_eiface.h>
#include <netgraph/ng_bridge.h>
#include <sys/user.h>
#include <libutil.h>

#include <sys/jail.h>

#include "/usr/src/sbin/mount/mntopts.h"
#include <sys/mount.h>

int
DestroyNetgraphNode(u32 ID, fd Control)
{
	char Path[NG_PATHSIZ];
	snprintf(Path, sizeof(Path), "[%x]:", ID);
	if(NgSendMsg(Control, Path, NGM_GENERIC_COOKIE, NGM_SHUTDOWN, NULL, 0) == -1)
	{
		fprintf(stderr, "ngctl shutdown %s: %s\n", Path, strerror(errno));
		return -1;
	}
	return 0;
}

int
Create_eiface(u32 *ID, fd Control)
{
	*ID = 0;
	{
		struct ngm_mkpeer D;
		strcpy(D.type, "eiface");
		strcpy(D.ourhook, "_");
		strcpy(D.peerhook, "ether");
		if(NgSendMsg(Control, ".:", NGM_GENERIC_COOKIE, NGM_MKPEER, &D, sizeof(D)) == -1)
		{
			fprintf(stderr, "ngctl mkpeer .: eiface _  ether: %s\n", strerror(errno));
			goto error;
		}
	}
	{
		if(NgSendMsg(Control, ".:_", NGM_GENERIC_COOKIE, NGM_NODEINFO, NULL, 0) == -1)
		{
			fprintf(stderr, "ngctl info .:_ : %s\n", strerror(errno));
			goto error;
		}
		struct ng_mesg *Response;
		if(NgAllocRecvMsg(Control, &Response, NULL) == -1)
		{
			fprintf(stderr, "NgAllocRecvMsg: %s\n", strerror(errno));
			return -1;
		}
		struct nodeinfo *Info = (void *)Response->data;
		*ID                   = Info->id;
		free(Response);
	}
	{
		struct ngm_rmhook D;
		strcpy(D.ourhook, "_");
		if(NgSendMsg(Control, ".:", NGM_GENERIC_COOKIE, NGM_RMHOOK, &D, sizeof(D)) == -1)
		{
			fprintf(stderr, "ngctl rmhook .: _: %s\n", strerror(errno));
			goto error;
		}
	}
	return 0;
error:
	if(*ID != 0) DestroyNetgraphNode(*ID, Control);
	return -1;
}

int
Create_bridge(u32 *ID, fd Control)
{
	*ID = 0;
	{
		struct ngm_mkpeer D;
		strcpy(D.type, "bridge");
		strcpy(D.ourhook, "_");
		strcpy(D.peerhook, "link0");
		if(NgSendMsg(Control, ".:", NGM_GENERIC_COOKIE, NGM_MKPEER, &D, sizeof(D)) == -1)
		{
			fprintf(stderr, "ngctl mkpeer .: eiface _  ether: %s\n", strerror(errno));
			goto error;
		}
	}
	{
		if(NgSendMsg(Control, ".:_", NGM_BRIDGE_COOKIE, NGM_BRIDGE_SET_PERSISTENT, NULL, 0) == -1)
		{
			fprintf(stderr, "ngctl msg .:_ setpersistent: %s\n", strerror(errno));
			goto error;
		}
	}
	{
		if(NgSendMsg(Control, ".:_", NGM_GENERIC_COOKIE, NGM_NODEINFO, NULL, 0) == -1)
		{
			fprintf(stderr, "ngctl info .:_ : %s\n", strerror(errno));
			goto error;
		}
		struct ng_mesg *Response;
		if(NgAllocRecvMsg(Control, &Response, NULL) == -1)
		{
			fprintf(stderr, "NgAllocRecvMsg: %s\n", strerror(errno));
			return -1;
		}
		struct nodeinfo *Info = (void *)Response->data;
		*ID                   = Info->id;
		free(Response);
	}
	{
		struct ngm_rmhook D;
		strcpy(D.ourhook, "_");
		if(NgSendMsg(Control, ".:", NGM_GENERIC_COOKIE, NGM_RMHOOK, &D, sizeof(D)) == -1)
		{
			fprintf(stderr, "ngctl rmhook .: _: %s\n", strerror(errno));
			goto error;
		}
	}
	return 0;
error:
	if(*ID != 0) DestroyNetgraphNode(*ID, Control);
	return -1;
}

char *
getifname(u32 ID, fd Control)
{
	struct ng_mesg *Response;
	char            Path[NG_PATHSIZ];
	snprintf(Path, sizeof(Path), "[%x]:", ID);
	if(NgSendMsg(Control, Path, NGM_EIFACE_COOKIE, NGM_EIFACE_GET_IFNAME, NULL, 0) == -1)
	{
		fprintf(stderr, "ngctl msg %s getifname: %s\n", Path, strerror(errno));
		return NULL;
	}
	if(NgAllocRecvMsg(Control, &Response, NULL) == -1)
	{
		fprintf(stderr, "NgAllocRecvMsg: %s\n", strerror(errno));
		return NULL;
	}
	char *Result = strdup((void *)Response->data);
	free(Response);
	return Result;
}

void
close_all(void)
{
	int                Count;
	struct kinfo_file *Result = kinfo_getfile(getpid(), &Count);
	if(Result == NULL) return;
	for(int i = 0; i < Count; ++i)
	{
		if(Result[i].kf_fd > STDERR_FILENO) close(Result[i].kf_fd);
	}
	free(Result);
}

int
command_a(char const *Program, char **Arg)
{
	pid_t PID = -1;
	PID       = fork();
	if(PID == -1)
	{
		fprintf(stderr, "fork failed: %s\n", strerror(errno));
		goto error;
	}
	if(PID == 0)
	{
		close(STDIN_FILENO);
		close(STDOUT_FILENO);
		dup2(STDERR_FILENO, STDOUT_FILENO);
		close_all();
		execvp(Program, Arg);
		fprintf(stderr, "exec failed: %s\n", strerror(errno));
		exit(-1);
	}
	int Status;
	waitpid(PID, &Status, 0);
	if(!WIFEXITED(Status) || (WEXITSTATUS(Status) != 0)) return -1;
	return 0;
error:
	return -1;
}

int
command_v(char const *Program, va_list Arg)
{
	va_list Arg_;
	va_copy(Arg_, Arg);
	size_t ArgCount = 0;
	do {
		char const *_ = va_arg(Arg_, char const *);
		++ArgCount;
		if(_ == NULL) break;
	} while(true);
	va_end(Arg_);
	char **Args = alloca(sizeof(char *) * ArgCount);
	for(size_t i = 0; i < ArgCount; ++i) Args[i] = va_arg(Arg, char *);
	return command_a(Program, Args);
}

int
command(char const *Program, ...)
{
	va_list Arg;
	va_start(Arg, Program);
	int Result = command_v(Program, Arg);
	va_end(Arg);
	return Result;
}

void
Free_string_array(string_array *E)
{
	for(size_t i = 0; i < E->Count; ++i) free(E->_[i]);
	if(E->_ != NULL) free(E->_);
}

char *
Parse_string_array(string_array *E, ucl_object_t const *root, char const *Position)
{
	char *Error;
	UCL_CHECK_ROOT(ARRAY);
	E->Count             = root->len;
	E->_                 = calloc(sizeof(char *), E->Count + 1); // NOTE: we null-terminate it
	ucl_object_iter_t it = NULL;
	for(E->Count = 0; E->Count < root->len; ++E->Count)
	{
		ucl_object_t const *v = ucl_iterate_object(root, &it, true);
		if(v == NULL) break;
		char const *k = ucl_object_key(v);
		if(k != NULL) continue;
		if(v->type != UCL_STRING)
		{
			asprintf(&Error, "%s[%zu] is not a string", Position, E->Count);
			goto error;
		}
		E->_[E->Count] = strdup(ucl_object_tostring(v));
	}
	return NULL;
error:
	Free_string_array(E);
	return Error;
}

void
Save_string_array(jprint_state *S, string_array const *E)
{
	JPrintArrayBegin(S);
	for(size_t i = 0; i < E->Count; ++i) JPrint_string(S, E->_[i]);
	JPrintArrayEnd(S);
}

int
exec_string_array(string_array *E, bool Wait, jid_t JID)
{
	if(E->Count == 0) return 0;
	pid_t PID = fork();
	if(PID == -1) return -1;
	if(PID == 0)
	{
		close(STDIN_FILENO);
		dup2(STDERR_FILENO, STDOUT_FILENO);
		close_all();
		if(JID != 0)
		{
			if(jail_attach(JID) == -1)
			{
				fprintf(stderr, "failed to attach to jail %d: %s\n", JID, strerror(errno));
				exit(-1);
			}
		}
		execvp(E->_[0], E->_);
		fprintf(stderr, "failed exec '%s': %s\n", E->_[0], strerror(errno));
		exit(-1);
	}
	if(Wait == true)
	{
		int Exit;
		waitpid(PID, &Exit, 0);
		if(!WIFEXITED(Exit) || (WEXITSTATUS(Exit) != 0)) return -1;
	}
	return 0;
}

static int
subdir(char const *p, char const *dir)
{
	size_t l = strlen(dir);
	if(l <= 1) return 1;
	if((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) return 1;
	return 0;
}

int
mount_unionfs(char const *Target, char const *Source, bool Below)
{
	char TargetR[MAXPATHLEN];
	char SourceR[MAXPATHLEN];
	if(checkpath(Target, TargetR) != 0)
	{
		fprintf(stderr, "checkpath %s\n", TargetR);
		return -1;
	}
	if(checkpath(Source, SourceR) != 0)
	{
		fprintf(stderr, "checkpath %s\n", SourceR);
		return -1;
	}
	if(subdir(TargetR, SourceR) || subdir(SourceR, TargetR))
	{
		fprintf(stderr, "%s (%s) and %s (%s) are not distinct paths\n", Target, TargetR, Source, SourceR);
		return -1;
	}
	char errmsg[255];
	bzero(errmsg, sizeof(errmsg));
	struct iovec *iov    = NULL;
	int           iovlen = 0;
	build_iovec(&iov, &iovlen, "fstype", "unionfs", (size_t)-1);
	if(Below == true) build_iovec(&iov, &iovlen, "below", NULL, 0);
	build_iovec(&iov, &iovlen, "fspath", TargetR, (size_t)-1);
	build_iovec(&iov, &iovlen, "from", SourceR, (size_t)-1);
	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
	if(nmount(iov, (u32)iovlen, 0))
	{
		fprintf(stderr, "nmount unionfs %s: %s\n", SourceR, errmsg);
		return -1;
	}
	return 0;
}

int
mount_devfs(char const *Target)
{
	char TargetR[MAXPATHLEN];
	if(checkpath(Target, TargetR) != 0)
	{
		fprintf(stderr, "checkpath %s\n", TargetR);
		return -1;
	}
	char errmsg[255];
	bzero(errmsg, sizeof(errmsg));
	struct iovec *iov    = NULL;
	int           iovlen = 0;
	build_iovec(&iov, &iovlen, "fstype", "devfs", (size_t)-1);
	build_iovec(&iov, &iovlen, "fspath", TargetR, (size_t)-1);
	build_iovec(&iov, &iovlen, "from", "devfs", (size_t)-1);
	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
	if(nmount(iov, (u32)iovlen, 0))
	{
		fprintf(stderr, "nmount devfs: %s\n", errmsg);
		return -1;
	}
	return 0;
}

int
mount_nullfs(char const *Target, char const *Source)
{
	char TargetR[MAXPATHLEN];
	char SourceR[MAXPATHLEN];
	if(checkpath(Target, TargetR) != 0)
	{
		fprintf(stderr, "checkpath %s\n", TargetR);
		return -1;
	}
	if(checkpath(Source, SourceR) != 0)
	{
		fprintf(stderr, "checkpath %s\n", SourceR);
		return -1;
	}
	if(subdir(TargetR, SourceR) || subdir(SourceR, TargetR))
	{
		fprintf(stderr, "%s (%s) and %s (%s) are not distinct paths\n", Target, TargetR, Source, SourceR);
		return -1;
	}
	char errmsg[255];
	bzero(errmsg, sizeof(errmsg));
	struct iovec *iov    = NULL;
	int           iovlen = 0;
	build_iovec(&iov, &iovlen, "fstype", "nullfs", (size_t)-1);
	build_iovec(&iov, &iovlen, "fspath", TargetR, (size_t)-1);
	build_iovec(&iov, &iovlen, "from", SourceR, (size_t)-1);
	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
	if(nmount(iov, (u32)iovlen, 0))
	{
		fprintf(stderr, "nmount nullfs %s: %s\n", SourceR, errmsg);
		return -1;
	}
	return 0;
}