From 9280c577431401544e63dfb489a830a42bee25eb Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 20 Apr 2023 13:56:31 -0400 Subject: [PATCH] NFSD: Handle new xprtsec= export option Enable administrators to require clients to use transport layer security when accessing particular exports. Signed-off-by: Chuck Lever --- fs/nfsd/export.c | 51 +++++++++++++++++++++++++++++++++++++--- fs/nfsd/export.h | 1 + include/uapi/linux/nfsd/export.h | 13 ++++++++++ 3 files changed, 62 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 6da74ae..ae85257 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -439,7 +439,6 @@ static int check_export(struct path *path, int *flags, unsigned char *uuid) return -EINVAL; } return 0; - } #ifdef CONFIG_NFSD_V4 @@ -546,6 +545,29 @@ static inline int secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; } #endif +static int xprtsec_parse(char **mesg, char *buf, struct svc_export *exp) +{ + unsigned int i, mode, listsize; + int err; + + err = get_uint(mesg, &listsize); + if (err) + return err; + if (listsize > NFSEXP_XPRTSEC_NUM) + return -EINVAL; + + exp->ex_xprtsec_modes = 0; + for (i = 0; i < listsize; i++) { + err = get_uint(mesg, &mode); + if (err) + return err; + if (mode > NFSEXP_XPRTSEC_MTLS) + return -EINVAL; + exp->ex_xprtsec_modes |= mode; + } + return 0; +} + static inline int nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid) { @@ -608,6 +630,7 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) exp.ex_client = dom; exp.cd = cd; exp.ex_devid_map = NULL; + exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL; /* expiry */ err = get_expiry(&mesg, &exp.h.expiry_time); @@ -649,6 +672,8 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid); else if (strcmp(buf, "secinfo") == 0) err = secinfo_parse(&mesg, buf, &exp); + else if (strcmp(buf, "xprtsec") == 0) + err = xprtsec_parse(&mesg, buf, &exp); else /* quietly ignore unknown words and anything * following. Newer user-space can try to set @@ -662,6 +687,7 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid); if (err) goto out4; + /* * No point caching this if it would immediately expire. * Also, this protects exportfs's dummy export from the @@ -823,6 +849,7 @@ static void export_update(struct cache_head *cnew, struct cache_head *citem) for (i = 0; i < MAX_SECINFO_LIST; i++) { new->ex_flavors[i] = item->ex_flavors[i]; } + new->ex_xprtsec_modes = item->ex_xprtsec_modes; } static struct cache_head *svc_export_alloc(void) @@ -1034,9 +1061,26 @@ static struct svc_export *exp_find(struct cache_detail *cd, __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) { - struct exp_flavor_info *f; - struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors; + struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors; + struct svc_xprt *xprt = rqstp->rq_xprt; + + if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) { + if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags)) + goto ok; + } + if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) { + if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) && + !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags)) + goto ok; + } + if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) { + if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) && + test_bit(XPT_PEER_AUTH, &xprt->xpt_flags)) + goto ok; + } + goto denied; +ok: /* legacy gss-only clients are always OK: */ if (exp->ex_client == rqstp->rq_gssclient) return 0; @@ -1061,6 +1105,7 @@ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) if (nfsd4_spo_must_allow(rqstp)) return 0; +denied: return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec; } diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h index d03f7f6..2df8ae2 100644 --- a/fs/nfsd/export.h +++ b/fs/nfsd/export.h @@ -77,6 +77,7 @@ struct svc_export { struct cache_detail *cd; struct rcu_head ex_rcu; struct export_stats ex_stats; + unsigned long ex_xprtsec_modes; }; /* an "export key" (expkey) maps a filehandlefragement to an diff --git a/include/uapi/linux/nfsd/export.h b/include/uapi/linux/nfsd/export.h index 2124ba9..a73ca37 100644 --- a/include/uapi/linux/nfsd/export.h +++ b/include/uapi/linux/nfsd/export.h @@ -62,5 +62,18 @@ | NFSEXP_ALLSQUASH \ | NFSEXP_INSECURE_PORT) +/* + * Transport layer security policies that are permitted to access + * an export + */ +#define NFSEXP_XPRTSEC_NONE 0x0001 +#define NFSEXP_XPRTSEC_TLS 0x0002 +#define NFSEXP_XPRTSEC_MTLS 0x0004 + +#define NFSEXP_XPRTSEC_NUM (3) + +#define NFSEXP_XPRTSEC_ALL (NFSEXP_XPRTSEC_NONE | \ + NFSEXP_XPRTSEC_TLS | \ + NFSEXP_XPRTSEC_MTLS) #endif /* _UAPINFSD_EXPORT_H */ -- 2.7.4