Annotation of qemu/migration-unix.c, revision 1.1.1.4

1.1       root        1: /*
                      2:  * QEMU live migration via Unix Domain Sockets
                      3:  *
                      4:  * Copyright Red Hat, Inc. 2009
                      5:  *
                      6:  * Authors:
                      7:  *  Chris Lalancette <clalance@redhat.com>
                      8:  *
                      9:  * This work is licensed under the terms of the GNU GPL, version 2.  See
                     10:  * the COPYING file in the top-level directory.
                     11:  *
                     12:  */
                     13: 
                     14: #include "qemu-common.h"
                     15: #include "qemu_socket.h"
                     16: #include "migration.h"
                     17: #include "qemu-char.h"
                     18: #include "buffered_file.h"
                     19: #include "block.h"
                     20: 
                     21: //#define DEBUG_MIGRATION_UNIX
                     22: 
                     23: #ifdef DEBUG_MIGRATION_UNIX
1.1.1.2   root       24: #define DPRINTF(fmt, ...) \
1.1       root       25:     do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
                     26: #else
1.1.1.2   root       27: #define DPRINTF(fmt, ...) \
1.1       root       28:     do { } while (0)
                     29: #endif
                     30: 
1.1.1.4 ! root       31: static int unix_errno(MigrationState *s)
1.1       root       32: {
                     33:     return errno;
                     34: }
                     35: 
1.1.1.4 ! root       36: static int unix_write(MigrationState *s, const void * buf, size_t size)
1.1       root       37: {
                     38:     return write(s->fd, buf, size);
                     39: }
                     40: 
1.1.1.4 ! root       41: static int unix_close(MigrationState *s)
1.1       root       42: {
1.1.1.2   root       43:     DPRINTF("unix_close\n");
1.1       root       44:     if (s->fd != -1) {
                     45:         close(s->fd);
                     46:         s->fd = -1;
                     47:     }
                     48:     return 0;
                     49: }
                     50: 
                     51: static void unix_wait_for_connect(void *opaque)
                     52: {
1.1.1.4 ! root       53:     MigrationState *s = opaque;
1.1       root       54:     int val, ret;
                     55:     socklen_t valsize = sizeof(val);
                     56: 
1.1.1.2   root       57:     DPRINTF("connect completed\n");
1.1       root       58:     do {
                     59:         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
1.1.1.4 ! root       60:     } while (ret == -1 && errno == EINTR);
1.1       root       61: 
                     62:     if (ret < 0) {
                     63:         migrate_fd_error(s);
                     64:         return;
                     65:     }
                     66: 
                     67:     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
                     68: 
                     69:     if (val == 0)
                     70:         migrate_fd_connect(s);
                     71:     else {
1.1.1.2   root       72:         DPRINTF("error connecting %d\n", val);
1.1       root       73:         migrate_fd_error(s);
                     74:     }
                     75: }
                     76: 
1.1.1.4 ! root       77: int unix_start_outgoing_migration(MigrationState *s, const char *path)
1.1       root       78: {
                     79:     struct sockaddr_un addr;
                     80:     int ret;
                     81: 
                     82:     addr.sun_family = AF_UNIX;
                     83:     snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
                     84:     s->get_error = unix_errno;
                     85:     s->write = unix_write;
                     86:     s->close = unix_close;
1.1.1.4 ! root       87: 
1.1       root       88:     s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
1.1.1.4 ! root       89:     if (s->fd == -1) {
1.1.1.2   root       90:         DPRINTF("Unable to open socket");
1.1.1.4 ! root       91:         return -errno;
1.1       root       92:     }
                     93: 
                     94:     socket_set_nonblock(s->fd);
                     95: 
                     96:     do {
                     97:         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
1.1.1.4 ! root       98:         if (ret == -1) {
        !            99:             ret = -errno;
        !           100:         }
        !           101:         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
1.1       root      102:            qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
1.1.1.4 ! root      103:             return 0;
        !           104:         }
1.1       root      105:     } while (ret == -EINTR);
                    106: 
1.1.1.4 ! root      107:     if (ret < 0) {
1.1.1.2   root      108:         DPRINTF("connect failed\n");
1.1.1.4 ! root      109:         migrate_fd_error(s);
        !           110:         return ret;
1.1       root      111:     }
1.1.1.4 ! root      112:     migrate_fd_connect(s);
        !           113:     return 0;
1.1       root      114: }
                    115: 
                    116: static void unix_accept_incoming_migration(void *opaque)
                    117: {
                    118:     struct sockaddr_un addr;
                    119:     socklen_t addrlen = sizeof(addr);
1.1.1.3   root      120:     int s = (intptr_t)opaque;
1.1       root      121:     QEMUFile *f;
1.1.1.2   root      122:     int c;
1.1       root      123: 
                    124:     do {
                    125:         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
1.1.1.4 ! root      126:     } while (c == -1 && errno == EINTR);
1.1       root      127: 
1.1.1.2   root      128:     DPRINTF("accepted migration\n");
1.1       root      129: 
                    130:     if (c == -1) {
                    131:         fprintf(stderr, "could not accept migration connection\n");
1.1.1.4 ! root      132:         goto out2;
1.1       root      133:     }
                    134: 
                    135:     f = qemu_fopen_socket(c);
                    136:     if (f == NULL) {
                    137:         fprintf(stderr, "could not qemu_fopen socket\n");
                    138:         goto out;
                    139:     }
                    140: 
1.1.1.2   root      141:     process_incoming_migration(f);
1.1       root      142:     qemu_fclose(f);
                    143: out:
1.1.1.4 ! root      144:     close(c);
        !           145: out2:
1.1.1.2   root      146:     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
                    147:     close(s);
1.1       root      148: }
                    149: 
                    150: int unix_start_incoming_migration(const char *path)
                    151: {
1.1.1.4 ! root      152:     struct sockaddr_un addr;
        !           153:     int s;
        !           154:     int ret;
1.1       root      155: 
1.1.1.2   root      156:     DPRINTF("Attempting to start an incoming migration\n");
1.1       root      157: 
1.1.1.4 ! root      158:     s = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
        !           159:     if (s == -1) {
1.1       root      160:         fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
1.1.1.4 ! root      161:         return -errno;
1.1       root      162:     }
                    163: 
1.1.1.4 ! root      164:     memset(&addr, 0, sizeof(addr));
        !           165:     addr.sun_family = AF_UNIX;
        !           166:     snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
1.1       root      167: 
1.1.1.4 ! root      168:     unlink(addr.sun_path);
        !           169:     if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
        !           170:         ret = -errno;
        !           171:         fprintf(stderr, "bind(unix:%s): %s\n", addr.sun_path, strerror(errno));
1.1       root      172:         goto err;
                    173:     }
1.1.1.4 ! root      174:     if (listen(s, 1) == -1) {
        !           175:         fprintf(stderr, "listen(unix:%s): %s\n", addr.sun_path,
        !           176:                 strerror(errno));
        !           177:         ret = -errno;
1.1       root      178:         goto err;
                    179:     }
                    180: 
1.1.1.4 ! root      181:     qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL,
        !           182:                          (void *)(intptr_t)s);
1.1       root      183: 
                    184:     return 0;
                    185: 
                    186: err:
1.1.1.4 ! root      187:     close(s);
        !           188:     return ret;
1.1       root      189: }

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