--- p2v/conversion.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/p2v/conversion.c b/p2v/conversion.c index 4ff7ecc..5c0c78e 100644 --- a/p2v/conversion.c +++ b/p2v/conversion.c @@ -44,6 +44,16 @@ /* How long to wait for qemu-nbd to start (seconds). */ #define WAIT_QEMU_NBD_TIMEOUT 10 +/* Source port for probing qemu-nbd. Should be one greater than + * nbd_local_port in ssh.c (50123). It's not guaranteed to always + * bind to 50124, but it will hint the kernel to start there and try + * incrementally higher ports if needed. This avoids the case where + * the kernel selects 50123 as our source port, and we immediately + * connect to ourself. + * See: https://bugzilla.redhat.com/show_bug.cgi?id=1167774#c9 + */ +static int nbd_probe_port = 50124; + /* Data per NBD connection / physical disk. */ struct data_conn { mexp_h *h; /* miniexpect handle to ssh */ @@ -398,7 +408,7 @@ wait_qemu_nbd (int nbd_local_port, int timeout_seconds) { int sockfd; int result = -1; - struct sockaddr_in addr; + struct sockaddr_in src_addr, dst_addr; time_t start_t, now_t; struct timeval timeout = { .tv_usec = 0 }; char magic[8]; /* NBDMAGIC */ @@ -413,10 +423,20 @@ wait_qemu_nbd (int nbd_local_port, int timeout_seconds) return -1; } - memset (&addr, 0, sizeof addr); - addr.sin_family = AF_INET; - addr.sin_port = htons (nbd_local_port); - inet_pton (AF_INET, "localhost", &addr.sin_addr); + memset (&src_addr, 0, sizeof src_addr); + src_addr.sin_family = AF_INET; + src_addr.sin_port = htons (nbd_probe_port); + inet_pton (AF_INET, "localhost", &src_addr.sin_addr); + + memset (&dst_addr, 0, sizeof dst_addr); + dst_addr.sin_family = AF_INET; + dst_addr.sin_port = htons (nbd_local_port); + inet_pton (AF_INET, "localhost", &dst_addr.sin_addr); + + if (bind (sockfd, (struct sockaddr *) &src_addr, sizeof src_addr) == -1) { + perror ("bind"); + return -1; + } for (;;) { time (&now_t); @@ -426,7 +446,7 @@ wait_qemu_nbd (int nbd_local_port, int timeout_seconds) goto cleanup; } - if (connect (sockfd, (struct sockaddr *) &addr, sizeof addr) == 0) + if (connect (sockfd, (struct sockaddr *) &dst_addr, sizeof dst_addr) == 0) break; } -- 2.1.0