[Libguestfs] [PATCH] p2v: wait for qemu-nbd before starting conversion (RHBZ#1167774)

Wait up to 10 seconds for qemu-nbd to start up and respond to clients. Otherwise the conversion server may attempt to connect before qemu-nbd is ready to serve it. --- p2v/conversion.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ p2v/p2v.h | 1 + 2 files changed, 73 insertions(+) diff --git a/p2v/conversion.c b/p2v/conversion.c index cb2deed..1aefcc6 100644 --- a/p2v/conversion.c +++ b/p2v/conversion.c @@ -31,6 +31,8 @@ #include <libintl.h> #include <sys/types.h> #include <sys/wait.h> +#include <arpa/inet.h> +#include <netinet/in.h> #include <glib.h> @@ -49,6 +51,7 @@ struct data_conn { static int send_quoted (mexp_h *, const char *s); static pid_t start_qemu_nbd (int nbd_local_port, const char *device); +static int wait_qemu_nbd (int nbd_local_port, int timeout_seconds); static void cleanup_data_conns (struct data_conn *data_conns, size_t nr); static char *generate_libvirt_xml (struct config *, struct data_conn *); static const char *map_interface_to_network (struct config *, const char *interface); @@ -156,6 +159,12 @@ start_conversion (struct config *config, if (data_conns[i].nbd_pid == 0) goto out; + /* Wait for qemu-nbd to listen */ + if (wait_qemu_nbd (data_conns[i].nbd_local_port, WAIT_QEMU_NBD_TIMEOUT) == -1) { + set_conversion_error("unable to connect to qemu-nbd"); + goto out; + } + #if DEBUG_STDERR fprintf (stderr, "%s: data connection for %s: SSH remote port %d, local port %d\n", @@ -371,6 +380,69 @@ start_qemu_nbd (int port, const char *device) return pid; } +static int +wait_qemu_nbd (int nbd_local_port, int timeout_seconds) +{ + int sockfd; + int result = 0; + struct sockaddr_in addr; + time_t start_t, now_t; + struct timeval timeout = { .tv_usec = 0 }; + char magic[8]; /* NBDMAGIC */ + size_t bytes_read = 0; + ssize_t recvd; + + time (&start_t); + + sockfd = socket (AF_INET, SOCK_STREAM, 0); + if (sockfd == -1) { + perror ("socket"); + return -1; + } + + memset(&addr, 0, sizeof (struct sockaddr_in)); + addr.sin_family = AF_INET; + addr.sin_port = htons(nbd_local_port); + inet_pton(AF_INET, "localhost", &addr.sin_addr); + + for (;;) { + time (&now_t); + + if (now_t - start_t >= timeout_seconds) { + perror("connect"); + result = -1; + goto cleanup; + } + + if (connect (sockfd, (struct sockaddr *) &addr, sizeof addr) == 0) + break; + } + + time (&now_t); + timeout.tv_sec = (start_t + timeout_seconds) - now_t; + setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(struct timeval)); + + do { + recvd = recv (sockfd, magic, sizeof(magic)-bytes_read, 0); + + if (recvd == -1) { + perror("recv"); + result = -1; + goto cleanup; + } + + bytes_read += recvd; + } while (bytes_read < sizeof magic); + + if (strncmp(magic, "NBDMAGIC", sizeof magic)) + result = -1; + +cleanup: + close(sockfd); + + return result; +} + static void cleanup_data_conns (struct data_conn *data_conns, size_t nr) { diff --git a/p2v/p2v.h b/p2v/p2v.h index c3ca0f6..7c4c115 100644 --- a/p2v/p2v.h +++ b/p2v/p2v.h @@ -98,6 +98,7 @@ extern int start_conversion (struct config *, void (*notify_ui) (int type, const #define NOTIFY_STATUS 3 /* stage in conversion process */ extern const char *get_conversion_error (void); extern void cancel_conversion (void); +#define WAIT_QEMU_NBD_TIMEOUT 10 /* ssh.c */ extern int test_connection (struct config *); -- 1.9.3