> On Mar 21, 2023, at 7:55 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Mon, 2023-03-20 at 10:35 -0400, Chuck Lever wrote:
>> From: Chuck Lever <chuck.lever@xxxxxxxxxx>
>>
>> The overall goal is to enable administrators to require the use of
>> transport layer security when clients access particular exports.
>>
>> This patch adds support to exportfs to parse and display a new
>> xprtsec= export option. The setting is not yet passed to the kernel.
>>
>> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>> ---
>> support/include/nfs/export.h | 6 +++
>> support/include/nfslib.h | 14 +++++++
>> support/nfs/exports.c | 85 ++++++++++++++++++++++++++++++++++++++++++
>> utils/exportfs/exportfs.c | 1
>> 4 files changed, 106 insertions(+)
>>
>> diff --git a/support/include/nfs/export.h b/support/include/nfs/export.h
>> index 0eca828ee3ad..b29c6fa4f554 100644
>> --- a/support/include/nfs/export.h
>> +++ b/support/include/nfs/export.h
>> @@ -40,4 +40,10 @@
>> #define NFSEXP_OLD_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH \
>> | NFSEXP_ALLSQUASH)
>>
>> +enum {
>> + NFSEXP_XPRTSEC_NONE = 1,
>> + NFSEXP_XPRTSEC_TLS = 2,
>> + NFSEXP_XPRTSEC_MTLS = 3,
>> +};
>> +
>
> Can we put these into a uapi header somewhere and then just have
> nfs-utils use those if they're defined?
I moved these to include/uapi/linux/nfsd/export.h in the
kernel patches, and adjust the nfs-utils patches to use the
same numeric values in exportfs as the kernel.
But it's not clear how a uAPI header would become visible
during, say, an RPM build of nfs-utils. Does anyone know
how that works? The kernel docs I've read suggest uAPI is
for user space tools that actually live in the kernel source
tree.
I think the cases where only user space or only the kernel
support xprtsec should work OK: the kernel has a default
transport layer security policy of "all ok" and old kernels
ignore export options from user space they don't recognize.
>> #endif /* _NSF_EXPORT_H */
>> diff --git a/support/include/nfslib.h b/support/include/nfslib.h
>> index 6faba71bf0cd..9a188fb84790 100644
>> --- a/support/include/nfslib.h
>> +++ b/support/include/nfslib.h
>> @@ -62,6 +62,18 @@ struct sec_entry {
>> int flags;
>> };
>>
>> +#define XPRTSECMODE_COUNT 4
>> +
>> +struct xprtsec_info {
>> + const char *name;
>> + int number;
>> +};
>> +
>> +struct xprtsec_entry {
>> + const struct xprtsec_info *info;
>> + int flags;
>> +};
>> +
>> /*
>> * Data related to a single exports entry as returned by getexportent.
>> * FIXME: export options should probably be parsed at a later time to
>> @@ -83,6 +95,7 @@ struct exportent {
>> char * e_fslocdata;
>> char * e_uuid;
>> struct sec_entry e_secinfo[SECFLAVOR_COUNT+1];
>> + struct xprtsec_entry e_xprtsec[XPRTSECMODE_COUNT + 1];
>> unsigned int e_ttl;
>> char * e_realpath;
>> };
>> @@ -99,6 +112,7 @@ struct rmtabent {
>> void setexportent(char *fname, char *type);
>> struct exportent * getexportent(int,int);
>> void secinfo_show(FILE *fp, struct exportent *ep);
>> +void xprtsecinfo_show(FILE *fp, struct exportent *ep);
>> void putexportent(struct exportent *xep);
>> void endexportent(void);
>> struct exportent * mkexportent(char *hname, char *path, char *opts);
>> diff --git a/support/nfs/exports.c b/support/nfs/exports.c
>> index 7f12383981c3..da8ace3a65fd 100644
>> --- a/support/nfs/exports.c
>> +++ b/support/nfs/exports.c
>> @@ -99,6 +99,7 @@ static void init_exportent (struct exportent *ee, int fromkernel)
>> ee->e_fslocmethod = FSLOC_NONE;
>> ee->e_fslocdata = NULL;
>> ee->e_secinfo[0].flav = NULL;
>> + ee->e_xprtsec[0].info = NULL;
>> ee->e_nsquids = 0;
>> ee->e_nsqgids = 0;
>> ee->e_uuid = NULL;
>> @@ -248,6 +249,17 @@ void secinfo_show(FILE *fp, struct exportent *ep)
>> }
>> }
>>
>> +void xprtsecinfo_show(FILE *fp, struct exportent *ep)
>> +{
>> + struct xprtsec_entry *p1, *p2;
>> +
>> + for (p1 = ep->e_xprtsec; p1->info; p1 = p2) {
>> + fprintf(fp, ",xprtsec=%s", p1->info->name);
>> + for (p2 = p1 + 1; p2->info && (p1->flags == p2->flags); p2++)
>> + fprintf(fp, ":%s", p2->info->name);
>> + }
>> +}
>> +
>> static void
>> fprintpath(FILE *fp, const char *path)
>> {
>> @@ -344,6 +356,7 @@ putexportent(struct exportent *ep)
>> }
>> fprintf(fp, "anonuid=%d,anongid=%d", ep->e_anonuid, ep->e_anongid);
>> secinfo_show(fp, ep);
>> + xprtsecinfo_show(fp, ep);
>> fprintf(fp, ")\n");
>> }
>>
>> @@ -482,6 +495,75 @@ static unsigned int parse_flavors(char *str, struct exportent *ep)
>> return out;
>> }
>>
>> +static const struct xprtsec_info xprtsec_name2info[] = {
>> + { "none", NFSEXP_XPRTSEC_NONE },
>> + { "tls", NFSEXP_XPRTSEC_TLS },
>> + { "mtls", NFSEXP_XPRTSEC_MTLS },
>> + { NULL, 0 }
>> +};
>> +
>> +static const struct xprtsec_info *find_xprtsec_info(const char *name)
>> +{
>> + const struct xprtsec_info *info;
>> +
>> + for (info = xprtsec_name2info; info->name; info++)
>> + if (strcmp(info->name, name) == 0)
>> + return info;
>> + return NULL;
>> +}
>> +
>> +/*
>> + * Append the given xprtsec mode to the exportent's e_xprtsec array,
>> + * or do nothing if it's already there. Returns the index of flavor in
>> + * the resulting array in any case.
>> + */
>> +static int xprtsec_addmode(const struct xprtsec_info *info, struct exportent *ep)
>> +{
>> + struct xprtsec_entry *p;
>> +
>> + for (p = ep->e_xprtsec; p->info; p++)
>> + if (p->info == info || p->info->number == info->number)
>> + return p - ep->e_xprtsec;
>> +
>> + if (p - ep->e_xprtsec >= XPRTSECMODE_COUNT) {
>> + xlog(L_ERROR, "more than %d xprtsec modes on an export\n",
>> + XPRTSECMODE_COUNT);
>> + return -1;
>> + }
>> + p->info = info;
>> + p->flags = ep->e_flags;
>> + (p + 1)->info = NULL;
>> + return p - ep->e_xprtsec;
>> +}
>> +
>> +/*
>> + * @str is a colon seperated list of transport layer security modes.
>> + * Their order is recorded in @ep, and a bitmap corresponding to the
>> + * list is returned.
>> + *
>> + * A zero return indicates an error.
>> + */
>> +static unsigned int parse_xprtsec(char *str, struct exportent *ep)
>> +{
>> + unsigned int out = 0;
>> + char *name;
>> +
>> + while ((name = strsep(&str, ":"))) {
>> + const struct xprtsec_info *info = find_xprtsec_info(name);
>> + int bit;
>> +
>> + if (!info) {
>> + xlog(L_ERROR, "unknown xprtsec mode %s\n", name);
>> + return 0;
>> + }
>> + bit = xprtsec_addmode(info, ep);
>> + if (bit < 0)
>> + return 0;
>> + out |= 1 << bit;
>> + }
>> + return out;
>> +}
>> +
>> /* Sets the bits in @mask for the appropriate security flavor flags. */
>> static void setflags(int mask, unsigned int active, struct exportent *ep)
>> {
>> @@ -687,6 +769,9 @@ bad_option:
>> active = parse_flavors(opt+4, ep);
>> if (!active)
>> goto bad_option;
>> + } else if (strncmp(opt, "xprtsec=", 8) == 0) {
>> + if (!parse_xprtsec(opt + 8, ep))
>> + goto bad_option;
>> } else {
>> xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n",
>> flname, flline, opt);
>> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
>> index 6d79a5b3480d..37b9e4b3612d 100644
>> --- a/utils/exportfs/exportfs.c
>> +++ b/utils/exportfs/exportfs.c
>> @@ -743,6 +743,7 @@ dump(int verbose, int export_format)
>> #endif
>> }
>> secinfo_show(stdout, ep);
>> + xprtsecinfo_show(stdout, ep);
>> printf("%c\n", (c != '(')? ')' : ' ');
>> }
>> }
>>
>>
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
--
Chuck Lever
