cregit-Linux how code gets into the kernel

Release 4.10 fs/nfs_common/nfsacl.c

Directory: fs/nfs_common
/*
 * fs/nfs_common/nfsacl.c
 *
 *  Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
 */

/*
 * The Solaris nfsacl protocol represents some ACLs slightly differently
 * than POSIX 1003.1e draft 17 does (and we do):
 *
 *  - Minimal ACLs always have an ACL_MASK entry, so they have
 *    four instead of three entries.
 *  - The ACL_MASK entry in such minimal ACLs always has the same
 *    permissions as the ACL_GROUP_OBJ entry. (In extended ACLs
 *    the ACL_MASK and ACL_GROUP_OBJ entries may differ.)
 *  - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ
 *    entries contain the identifiers of the owner and owning group.
 *    (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).
 *  - ACL entries in the kernel are kept sorted in ascending order
 *    of (e_tag, e_id). Solaris ACLs are unsorted.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/sunrpc/xdr.h>
#include <linux/nfsacl.h>
#include <linux/nfs3.h>
#include <linux/sort.h>

MODULE_LICENSE("GPL");


struct nfsacl_encode_desc {
	
struct xdr_array2_desc desc;
	
unsigned int count;
	
struct posix_acl *acl;
	
int typeflag;
	
kuid_t uid;
	
kgid_t gid;
};


struct nfsacl_simple_acl {
	
struct posix_acl acl;
	
struct posix_acl_entry ace[4];
};


static int xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem) { struct nfsacl_encode_desc *nfsacl_desc = (struct nfsacl_encode_desc *) desc; __be32 *p = elem; struct posix_acl_entry *entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++]; *p++ = htonl(entry->e_tag | nfsacl_desc->typeflag); switch(entry->e_tag) { case ACL_USER_OBJ: *p++ = htonl(from_kuid(&init_user_ns, nfsacl_desc->uid)); break; case ACL_GROUP_OBJ: *p++ = htonl(from_kgid(&init_user_ns, nfsacl_desc->gid)); break; case ACL_USER: *p++ = htonl(from_kuid(&init_user_ns, entry->e_uid)); break; case ACL_GROUP: *p++ = htonl(from_kgid(&init_user_ns, entry->e_gid)); break; default: /* Solaris depends on that! */ *p++ = 0; break; } *p++ = htonl(entry->e_perm & S_IRWXO); return 0; }

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andreas gruenbacherandreas gruenbacher14579.23%133.33%
eric w. biedermaneric w. biederman3720.22%133.33%
al viroal viro10.55%133.33%
Total183100.00%3100.00%

/** * nfsacl_encode - Encode an NFSv3 ACL * * @buf: destination xdr_buf to contain XDR encoded ACL * @base: byte offset in xdr_buf where XDR'd ACL begins * @inode: inode of file whose ACL this is * @acl: posix_acl to encode * @encode_entries: whether to encode ACEs as well * @typeflag: ACL type: NFS_ACL_DEFAULT or zero * * Returns size of encoded ACL in bytes or a negative errno value. */
int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, struct posix_acl *acl, int encode_entries, int typeflag) { int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0; struct nfsacl_encode_desc nfsacl_desc = { .desc = { .elem_size = 12, .array_len = encode_entries ? entries : 0, .xcode = xdr_nfsace_encode, }, .acl = acl, .typeflag = typeflag, .uid = inode->i_uid, .gid = inode->i_gid, }; struct nfsacl_simple_acl aclbuf; int err; if (entries > NFS_ACL_MAX_ENTRIES || xdr_encode_word(buf, base, entries)) return -EINVAL; if (encode_entries && acl && acl->a_count == 3) { struct posix_acl *acl2 = &aclbuf.acl; /* Avoid the use of posix_acl_alloc(). nfsacl_encode() is * invoked in contexts where a memory allocation failure is * fatal. Fortunately this fake ACL is small enough to * construct on the stack. */ posix_acl_init(acl2, 4); /* Insert entries in canonical order: other orders seem to confuse Solaris VxFS. */ acl2->a_entries[0] = acl->a_entries[0]; /* ACL_USER_OBJ */ acl2->a_entries[1] = acl->a_entries[1]; /* ACL_GROUP_OBJ */ acl2->a_entries[2] = acl->a_entries[1]; /* ACL_MASK */ acl2->a_entries[2].e_tag = ACL_MASK; acl2->a_entries[3] = acl->a_entries[2]; /* ACL_OTHER */ nfsacl_desc.acl = acl2; } err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc); if (!err) err = 8 + nfsacl_desc.desc.elem_size * nfsacl_desc.desc.array_len; return err; }

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andreas gruenbacherandreas gruenbacher26392.61%250.00%
chuck leverchuck lever217.39%250.00%
Total284100.00%4100.00%

EXPORT_SYMBOL_GPL(nfsacl_encode); struct nfsacl_decode_desc { struct xdr_array2_desc desc; unsigned int count; struct posix_acl *acl; };
static int xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem) { struct nfsacl_decode_desc *nfsacl_desc = (struct nfsacl_decode_desc *) desc; __be32 *p = elem; struct posix_acl_entry *entry; unsigned int id; if (!nfsacl_desc->acl) { if (desc->array_len > NFS_ACL_MAX_ENTRIES) return -EINVAL; nfsacl_desc->acl = posix_acl_alloc(desc->array_len, GFP_KERNEL); if (!nfsacl_desc->acl) return -ENOMEM; nfsacl_desc->count = 0; } entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++]; entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT; id = ntohl(*p++); entry->e_perm = ntohl(*p++); switch(entry->e_tag) { case ACL_USER: entry->e_uid = make_kuid(&init_user_ns, id); if (!uid_valid(entry->e_uid)) return -EINVAL; break; case ACL_GROUP: entry->e_gid = make_kgid(&init_user_ns, id); if (!gid_valid(entry->e_gid)) return -EINVAL; break; case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_OTHER: if (entry->e_perm & ~S_IRWXO) return -EINVAL; break; case ACL_MASK: /* Solaris sometimes sets additional bits in the mask */ entry->e_perm &= S_IRWXO; break; default: return -EINVAL; } return 0; }

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eric w. biedermaneric w. biederman6325.00%125.00%
al viroal viro10.40%125.00%
lucas de marchilucas de marchi10.40%125.00%
Total252100.00%4100.00%


static int cmp_acl_entry(const void *x, const void *y) { const struct posix_acl_entry *a = x, *b = y; if (a->e_tag != b->e_tag) return a->e_tag - b->e_tag; else if ((a->e_tag == ACL_USER) && uid_gt(a->e_uid, b->e_uid)) return 1; else if ((a->e_tag == ACL_USER) && uid_lt(a->e_uid, b->e_uid)) return -1; else if ((a->e_tag == ACL_GROUP) && gid_gt(a->e_gid, b->e_gid)) return 1; else if ((a->e_tag == ACL_GROUP) && gid_lt(a->e_gid, b->e_gid)) return -1; else return 0; }

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eric w. biedermaneric w. biederman7951.30%150.00%
andreas gruenbacherandreas gruenbacher7548.70%150.00%
Total154100.00%2100.00%

/* * Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL. */
static int posix_acl_from_nfsacl(struct posix_acl *acl) { struct posix_acl_entry *pa, *pe, *group_obj = NULL, *mask = NULL; if (!acl) return 0; sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry), cmp_acl_entry, NULL); /* Find the ACL_GROUP_OBJ and ACL_MASK entries. */ FOREACH_ACL_ENTRY(pa, acl, pe) { switch(pa->e_tag) { case ACL_USER_OBJ: break; case ACL_GROUP_OBJ: group_obj = pa; break; case ACL_MASK: mask = pa; /* fall through */ case ACL_OTHER: break; } } if (acl->a_count == 4 && group_obj && mask && mask->e_perm == group_obj->e_perm) { /* remove bogus ACL_MASK entry */ memmove(mask, mask+1, (3 - (mask - acl->a_entries)) * sizeof(struct posix_acl_entry)); acl->a_count = 3; } return 0; }

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andreas gruenbacherandreas gruenbacher15999.38%150.00%
eric w. biedermaneric w. biederman10.62%150.00%
Total160100.00%2100.00%

/** * nfsacl_decode - Decode an NFSv3 ACL * * @buf: xdr_buf containing XDR'd ACL data to decode * @base: byte offset in xdr_buf where XDR'd ACL begins * @aclcnt: count of ACEs in decoded posix_acl * @pacl: buffer in which to place decoded posix_acl * * Returns the length of the decoded ACL in bytes, or a negative errno value. */
int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, struct posix_acl **pacl) { struct nfsacl_decode_desc nfsacl_desc = { .desc = { .elem_size = 12, .xcode = pacl ? xdr_nfsace_decode : NULL, }, }; u32 entries; int err; if (xdr_decode_word(buf, base, &entries) || entries > NFS_ACL_MAX_ENTRIES) return -EINVAL; nfsacl_desc.desc.array_maxlen = entries; err = xdr_decode_array2(buf, base + 4, &nfsacl_desc.desc); if (err) return err; if (pacl) { if (entries != nfsacl_desc.desc.array_len || posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) { posix_acl_release(nfsacl_desc.acl); return -EINVAL; } *pacl = nfsacl_desc.acl; } if (aclcnt) *aclcnt = entries; return 8 + nfsacl_desc.desc.elem_size * nfsacl_desc.desc.array_len; }

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andreas gruenbacherandreas gruenbacher16794.89%133.33%
trond myklebusttrond myklebust84.55%133.33%
chuck leverchuck lever10.57%133.33%
Total176100.00%3100.00%

EXPORT_SYMBOL_GPL(nfsacl_decode);

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andreas gruenbacherandreas gruenbacher106581.24%220.00%
eric w. biedermaneric w. biederman18213.88%110.00%
chuck leverchuck lever403.05%220.00%
fabian frederickfabian frederick100.76%110.00%
trond myklebusttrond myklebust80.61%110.00%
tejun heotejun heo30.23%110.00%
al viroal viro20.15%110.00%
lucas de marchilucas de marchi10.08%110.00%
Total1311100.00%10100.00%
Directory: fs/nfs_common
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