X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fproto.c;h=131c66be128d116b1c5837db35a7dc6530c29fb0;hp=f045751f5e66b1ba38aca57a977a249e710c4a43;hb=d134143b55ecb5f7e6f74318acbf04f9e1370af6;hpb=40ca9a57829f2e82362e391d7d998bf33c8bd671 diff --git a/daemon/proto.c b/daemon/proto.c index f045751..131c66b 100644 --- a/daemon/proto.c +++ b/daemon/proto.c @@ -23,10 +23,18 @@ #include #include #include +#include +#include #include #include #include "daemon.h" +#include "../src/guestfs_protocol.h" + +/* XXX We should make this configurable from /proc/cmdline so that the + * verbose setting of the guestfs_h can be inherited here. + */ +#define DEBUG 1 /* The message currently being processed. */ int proc_nr; @@ -38,22 +46,208 @@ static int sock; void main_loop (int _sock) { + XDR xdr; + char *buf; + char lenbuf[4]; + unsigned len; + struct guestfs_message_header hdr; + sock = _sock; - + for (;;) { + /* Read the length word. */ + xread (sock, lenbuf, 4); + xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE); + xdr_uint32_t (&xdr, &len); + xdr_destroy (&xdr); + + if (len > GUESTFS_MESSAGE_MAX) { + fprintf (stderr, "guestfsd: incoming message is too long (%u bytes)\n", + len); + exit (1); + } + + buf = malloc (len); + if (!buf) { + reply_with_perror ("malloc"); + continue; + } + + xread (sock, buf, len); + +#if DEBUG + int i, j; + +#define MIN(a,b) ((a)<(b)?(a):(b)) + + for (i = 0; i < len; i += 16) { + printf ("%04x: ", i); + for (j = i; j < MIN (i+16, len); ++j) + printf ("%02x ", (unsigned char) buf[j]); + for (; j < i+16; ++j) + printf (" "); + printf ("|"); + for (j = i; j < MIN (i+16, len); ++j) + if (isprint (buf[j])) + printf ("%c", buf[j]); + else + printf ("."); + for (; j < i+16; ++j) + printf (" "); + printf ("|\n"); + } +#endif + + /* Decode the message header. */ + xdrmem_create (&xdr, buf, len, XDR_DECODE); + if (!xdr_guestfs_message_header (&xdr, &hdr)) { + fprintf (stderr, "guestfsd: could not decode message header\n"); + exit (1); + } + /* Check the version etc. */ + if (hdr.prog != GUESTFS_PROGRAM) { + reply_with_error ("wrong program (%d)", hdr.prog); + goto cont; + } + if (hdr.vers != GUESTFS_PROTOCOL_VERSION) { + reply_with_error ("wrong protocol version (%d)", hdr.vers); + goto cont; + } + if (hdr.direction != GUESTFS_DIRECTION_CALL) { + reply_with_error ("unexpected message direction (%d)", hdr.direction); + goto cont; + } + if (hdr.status != GUESTFS_STATUS_OK) { + reply_with_error ("unexpected message status (%d)", hdr.status); + goto cont; + } + /* Now start to process this message. */ + proc_nr = hdr.proc; + serial = hdr.serial; + dispatch_incoming_message (&xdr); + /* Note that dispatch_incoming_message will also send a reply. */ + + cont: + xdr_destroy (&xdr); + free (buf); + } } +static void send_error (const char *msg); + void reply_with_error (const char *fs, ...) { - + char err[GUESTFS_ERROR_LEN]; + va_list args; + + va_start (args, fs); + vsnprintf (err, sizeof err, fs, args); + va_end (args); + + send_error (err); +} + +void +reply_with_perror (const char *fs, ...) +{ + char buf1[GUESTFS_ERROR_LEN]; + char buf2[GUESTFS_ERROR_LEN]; + va_list args; + int err = errno; + + va_start (args, fs); + vsnprintf (buf1, sizeof buf1, fs, args); + va_end (args); + + snprintf (buf2, sizeof buf2, "%s: %s", buf1, strerror (err)); + + send_error (buf2); +} + +static void +send_error (const char *msg) +{ + XDR xdr; + char buf[GUESTFS_ERROR_LEN + 200]; + char lenbuf[4]; + struct guestfs_message_header hdr; + struct guestfs_message_error err; + unsigned len; + + fprintf (stderr, "guestfsd: error: %s\n", msg); + + xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE); + + hdr.prog = GUESTFS_PROGRAM; + hdr.vers = GUESTFS_PROTOCOL_VERSION; + hdr.direction = GUESTFS_DIRECTION_REPLY; + hdr.status = GUESTFS_STATUS_ERROR; + hdr.proc = proc_nr; + hdr.serial = serial; + + if (!xdr_guestfs_message_header (&xdr, &hdr)) { + fprintf (stderr, "guestfsd: failed to encode error message header\n"); + exit (1); + } + + err.error = (char *) msg; + if (!xdr_guestfs_message_error (&xdr, &err)) { + fprintf (stderr, "guestfsd: failed to encode error message body\n"); + exit (1); + } + len = xdr_getpos (&xdr); + xdr_destroy (&xdr); + + xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE); + xdr_uint32_t (&xdr, &len); + xdr_destroy (&xdr); + + xwrite (sock, lenbuf, 4); + xwrite (sock, buf, len); } void -reply (xdrproc_t xdrp, XDR *xdr) +reply (xdrproc_t xdrp, char *ret) { + XDR xdr; + char buf[GUESTFS_MESSAGE_MAX]; + char lenbuf[4]; + struct guestfs_message_header hdr; + unsigned len; + + xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE); + + hdr.prog = GUESTFS_PROGRAM; + hdr.vers = GUESTFS_PROTOCOL_VERSION; + hdr.direction = GUESTFS_DIRECTION_REPLY; + hdr.status = GUESTFS_STATUS_OK; + hdr.proc = proc_nr; + hdr.serial = serial; + + if (!xdr_guestfs_message_header (&xdr, &hdr)) { + fprintf (stderr, "guestfsd: failed to encode reply header\n"); + exit (1); + } + + if (xdrp) { + if (!(*xdrp) (&xdr, ret)) { + fprintf (stderr, "guestfsd: failed to encode reply body\n"); + exit (1); + } + } + + len = xdr_getpos (&xdr); + xdr_destroy (&xdr); + + xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE); + xdr_uint32_t (&xdr, &len); + xdr_destroy (&xdr); + + xwrite (sock, lenbuf, 4); + xwrite (sock, buf, len); }