X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fstropts.c;h=1d2cde6d0386d4bfc702134b8f62b420289543bb;hp=6f57e86ed4633e59f94c4f38903f1b520ce406ad;hb=56cfa1320a00cec885fbdf51c54b72acb01a95c0;hpb=0e65b81caabbc0029d17a0a5042badb1417b2b4d diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c index 6f57e86..1d2cde6 100644 --- a/utils/mount/stropts.c +++ b/utils/mount/stropts.c @@ -237,6 +237,272 @@ static int set_mandatory_options(const char *type, return 1; } +/* + * Reconstruct the mount option string based on a portmapper probe + * of the server. Returns one if the server's portmapper returned + * something we can use, otherwise zero. + * + * To handle version and transport protocol fallback properly, we + * need to parse some of the mount options in order to set up a + * portmap probe. Mount options that rewrite_mount_options() + * doesn't recognize are left alone. + * + * Returns a new group of mount options if successful; otherwise + * NULL is returned if some failure occurred. + */ +static struct mount_options *rewrite_mount_options(char *str) +{ + struct mount_options *options; + char *option, new_option[64]; + clnt_addr_t mnt_server = { }; + clnt_addr_t nfs_server = { }; + int p; + + options = po_split(str); + if (!options) + return NULL; + + option = po_get(options, "addr"); + if (option) { + nfs_server.saddr.sin_family = AF_INET; + if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr)) + goto err; + } else + goto err; + + option = po_get(options, "mountaddr"); + if (option) { + mnt_server.saddr.sin_family = AF_INET; + if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr)) + goto err; + } else + memcpy(&mnt_server.saddr, &nfs_server.saddr, + sizeof(mnt_server.saddr)); + + option = po_get(options, "mountport"); + if (option) + mnt_server.pmap.pm_port = atoi(option); + mnt_server.pmap.pm_prog = MOUNTPROG; + option = po_get(options, "mountprog"); + if (option) + mnt_server.pmap.pm_prog = atoi(option); + option = po_get(options, "mountvers"); + if (option) + mnt_server.pmap.pm_vers = atoi(option); + + option = po_get(options, "port"); + if (option) { + nfs_server.pmap.pm_port = atoi(option); + po_remove_all(options, "port"); + } + nfs_server.pmap.pm_prog = NFS_PROGRAM; + option = po_get(options, "nfsprog"); + if (option) + nfs_server.pmap.pm_prog = atoi(option); + + option = po_get(options, "nfsvers"); + if (option) { + nfs_server.pmap.pm_vers = atoi(option); + po_remove_all(options, "nfsvers"); + } + option = po_get(options, "vers"); + if (option) { + nfs_server.pmap.pm_vers = atoi(option); + po_remove_all(options, "vers"); + } + option = po_get(options, "proto"); + if (option) { + if (strcmp(option, "tcp") == 0) { + nfs_server.pmap.pm_prot = IPPROTO_TCP; + po_remove_all(options, "proto"); + } + if (strcmp(option, "udp") == 0) { + nfs_server.pmap.pm_prot = IPPROTO_UDP; + po_remove_all(options, "proto"); + } + } + p = po_rightmost(options, "tcp", "udp"); + switch (p) { + case PO_KEY2_RIGHTMOST: + nfs_server.pmap.pm_prot = IPPROTO_UDP; + break; + case PO_KEY1_RIGHTMOST: + nfs_server.pmap.pm_prot = IPPROTO_TCP; + break; + } + po_remove_all(options, "tcp"); + po_remove_all(options, "udp"); + + if (!probe_bothports(&mnt_server, &nfs_server)) { + rpc_mount_errors("rpcbind", 0, 0); + goto err; + } + + snprintf(new_option, sizeof(new_option) - 1, + "nfsvers=%lu", nfs_server.pmap.pm_vers); + if (po_append(options, new_option) == PO_FAILED) + goto err; + + if (nfs_server.pmap.pm_prot == IPPROTO_TCP) + snprintf(new_option, sizeof(new_option) - 1, + "proto=tcp"); + else + snprintf(new_option, sizeof(new_option) - 1, + "proto=udp"); + if (po_append(options, new_option) == PO_FAILED) + goto err; + + if (nfs_server.pmap.pm_port != NFS_PORT) { + snprintf(new_option, sizeof(new_option) - 1, + "port=%lu", nfs_server.pmap.pm_port); + if (po_append(options, new_option) == PO_FAILED) + goto err; + + } + + return options; + +err: + po_destroy(options); + return NULL; +} + +/* + * Retry an NFS mount that failed because the requested service isn't + * available on the server. + * + * Returns 1 if successful. Otherwise, returns zero. + * "errno" is set to reflect the individual error. + * + * Side effect: If the retry is successful, both 'options' and + * 'extra_opts' are updated to reflect the mount options that worked. + * If the retry fails, 'options' and 'extra_opts' are left unchanged. + */ +static int retry_nfsmount(const char *spec, const char *node, + int flags, struct mount_options *options, + int fake, char **extra_opts) +{ + struct mount_options *retry_options; + char *retry_str = NULL; + + retry_options = rewrite_mount_options(*extra_opts); + if (!retry_options) { + errno = EIO; + return 0; + } + + if (po_join(retry_options, &retry_str) == PO_FAILED) { + po_destroy(retry_options); + errno = EIO; + return 0; + } + + if (verbose) + printf(_("%s: text-based options (retry): '%s'\n"), + progname, retry_str); + + if (!mount(spec, node, "nfs", + flags & ~(MS_USER|MS_USERS), retry_str)) { + free(*extra_opts); + *extra_opts = retry_str; + po_replace(options, retry_options); + return 1; + } + + po_destroy(retry_options); + free(retry_str); + return 0; +} + +/* + * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel + * claims the requested service isn't supported on the server, probe + * the server to see what's supported, rewrite the mount options, + * and retry the request. + * + * Returns 1 if successful. Otherwise, returns zero. + * "errno" is set to reflect the individual error. + * + * Side effect: If the retry is successful, both 'options' and + * 'extra_opts' are updated to reflect the mount options that worked. + * If the retry fails, 'options' and 'extra_opts' are left unchanged. + */ +static int try_nfs23mount(const char *spec, const char *node, + int flags, struct mount_options *options, + int fake, char **extra_opts) +{ + if (po_join(options, extra_opts) == PO_FAILED) { + errno = EIO; + return 0; + } + + if (verbose) + printf(_("%s: text-based options: '%s'\n"), + progname, *extra_opts); + + if (fake) + return 1; + + if (!mount(spec, node, "nfs", + flags & ~(MS_USER|MS_USERS), *extra_opts)) + return 1; + + /* + * The kernel returns EOPNOTSUPP if the RPC bind failed, + * and EPROTONOSUPPORT if the version isn't supported. + */ + if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT) + return 0; + + return retry_nfsmount(spec, node, flags, options, fake, extra_opts); +} + +/* + * Attempt an NFS v4 mount via a mount(2) system call. + * + * Returns 1 if successful. Otherwise, returns zero. + * "errno" is set to reflect the individual error. + */ +static int try_nfs4mount(const char *spec, const char *node, + int flags, struct mount_options *options, + int fake, char **extra_opts) +{ + if (po_join(options, extra_opts) == PO_FAILED) { + errno = EIO; + return 0; + } + + if (verbose) + printf(_("%s: text-based options: '%s'\n"), + progname, *extra_opts); + + if (fake) + return 1; + + if (!mount(spec, node, "nfs4", + flags & ~(MS_USER|MS_USERS), *extra_opts)) + return 1; + return 0; +} + +/* + * Try the mount(2) system call. + * + * Returns 1 if successful. Otherwise, returns zero. + * "errno" is set to reflect the individual error. + */ +static int try_mount(const char *spec, const char *node, const char *type, + int flags, struct mount_options *options, int fake, + char **extra_opts) +{ + if (strncmp(type, "nfs4", 4) == 0) + return try_nfs4mount(spec, node, flags, + options, fake, extra_opts); + else + return try_nfs23mount(spec, node, flags, + options, fake, extra_opts); +} + /** * nfsmount_string - Mount an NFS file system using C string options * @spec: C string specifying remote share to mount ("hostname:path")