diff options
Diffstat (limited to 'nfs/rpc.c')
| -rw-r--r-- | nfs/rpc.c | 176 |
1 files changed, 103 insertions, 73 deletions
@@ -28,7 +28,7 @@ #include <rpc/rpc_msg.h> #include <rpc/auth_unix.h> -#undef malloc /* Get rid protection. */ +#undef malloc /* Get rid of the sun block */ #include <netinet/in.h> #include <assert.h> @@ -43,7 +43,7 @@ struct rpc_list void *reply; }; -/* A list of all the pending RPCs. */ +/* A list of all pending RPCs. */ static struct rpc_list *outstanding_rpcs; /* Wake up this condition when an outstanding RPC has received a reply @@ -56,7 +56,7 @@ static struct mutex outstanding_lock = MUTEX_INITIALIZER; /* Generate and return a new transaction ID. */ -static int +static inline int generate_xid () { static int nextxid; @@ -67,22 +67,31 @@ generate_xid () return nextxid++; } -/* Set up an RPC for procdeure RPC_PROC, for talking to the server +/* Set up an RPC for procdeure RPC_PROC for talking to the server PROGRAM of version VERSION. Allocate storage with malloc and point *BUF at it; caller must free this when done. Allocate at least LEN - bytes more than the usual amount for an RPC. Initialize the RPC - credential structure with UID, GID, and SECOND_GID. (Any of those - may be -1 to indicate that it does not apply; exactly or two of UID - and GID must be -1, however.) */ + bytes more than the usual amount for the RPC. Initialize the RPC + credential structure with UID, GID, and SECOND_GID; any of these + may be -1 to indicate that it does not apply, however, exactly zero + or two of UID and GID must be -1. The returned address is a pointer + to the start of the payload. If NULL is returned, an error occured + and the code is set in errno. */ int * initialize_rpc (int program, int version, int rpc_proc, size_t len, void **bufp, uid_t uid, gid_t gid, gid_t second_gid) { - void *buf = malloc (len + 1024); + void *buf; int *p, *lenaddr; struct rpc_list *hdr; + buf = malloc (len + 1024); + if (! buf) + { + errno = ENOMEM; + return NULL; + } + /* First the struct rpc_list bit. */ hdr = buf; hdr->reply = 0; @@ -99,40 +108,44 @@ initialize_rpc (int program, int version, int rpc_proc, assert ((uid == -1) == (gid == -1)); - if (uid != -1) + if (uid == -1) + { + /* No authentication */ + *p++ = htonl (AUTH_NONE); + *p++ = 0; + } + else { + /* Unixy authentication */ *p++ = htonl (AUTH_UNIX); + /* The length of the message. We do not yet know what this + is, so, just remember where we should put it when we know */ lenaddr = p++; *p++ = htonl (mapped_time->seconds); p = xdr_encode_string (p, hostname); *p++ = htonl (uid); *p++ = htonl (gid); - if (second_gid != -1) + if (second_gid == -1) + *p++ = 0; + else { *p++ = htonl (1); *p++ = htonl (second_gid); } - else - *p++ = 0; *lenaddr = htonl ((p - (lenaddr + 1)) * sizeof (int)); } - else - { - *p++ = htonl (AUTH_NULL); - *p++ = 0; - } /* VERF field */ - *p++ = htonl (AUTH_NULL); + *p++ = htonl (AUTH_NONE); *p++ = 0; *bufp = buf; return p; } -/* Remove HDR from the list of pending RPC's. rpc_list_lock must be - held */ -static void +/* Remove HDR from the list of pending RPC's. The rpc_list's lock + (OUTSTANDING_LOCK) must be held */ +static inline void unlink_rpc (struct rpc_list *hdr) { *hdr->prevp = hdr->next; @@ -140,12 +153,24 @@ unlink_rpc (struct rpc_list *hdr) hdr->next->prevp = hdr->prevp; } +/* Insert HDR at the head of the LIST. The rpc_list's lock + (OUTSTANDING_LOCK) must be held */ +static inline void +link_rpc (struct rpc_list **list, struct rpc_list *hdr) +{ + hdr->next = *list; + if (hdr->next) + hdr->next->prevp = &hdr->next; + hdr->prevp = list; + *list = hdr; +} + /* Send the specified RPC message. *RPCBUF is the initialized buffer - from a previous initialize_rpc call; *PP points past the filled - in args. Set *PP to the address of the reply contents themselves. - The user will be expected to free *RPCBUF (which will have changed) - when done with the reply contents. The old value of *RPCBUF will - be freed by this routine. */ + from a previous initialize_rpc call; *PP, the payload, points past + the filledin args. Set *PP to the address of the reply contents + themselves. The user will be expected to free *RPCBUF (which will + have changed) when done with the reply contents. The old value of + *RPCBUF will be freed by this routine. */ error_t conduct_rpc (void **rpcbuf, int **pp) { @@ -162,12 +187,7 @@ conduct_rpc (void **rpcbuf, int **pp) mutex_lock (&outstanding_lock); - /* Link it in */ - hdr->next = outstanding_rpcs; - if (hdr->next) - hdr->next->prevp = &hdr->next; - hdr->prevp = &outstanding_rpcs; - outstanding_rpcs = hdr; + link_rpc (&outstanding_rpcs, hdr); xid = * (int *) (*rpcbuf + sizeof (struct rpc_list)); @@ -209,9 +229,12 @@ conduct_rpc (void **rpcbuf, int **pp) return EINTR; } + /* hdr->reply will have been filled in by rpc_receive_thread, + if it has been filled in, then the rpc has been fulfilled, + otherwise, retransmit and continue to wait */ if (!hdr->reply) { - timeout *=2; + timeout *= 2; if (timeout > max_transmit_timeout) timeout = max_transmit_timeout; } @@ -224,10 +247,12 @@ conduct_rpc (void **rpcbuf, int **pp) *rpcbuf = hdr->reply; free (hdr); - /* Process the reply, dissecting errors. When we're done, set *PP to - the rpc return contents, if there is no error. */ + /* Process the reply, dissecting errors. When we're done and if + there is no error, set *PP to the rpc return contents */ p = (int *) *rpcbuf; + /* If the transmition id does not match that in the message, + something strange happened in rpc_receive_thread */ assert (*p == xid); p++; @@ -315,7 +340,8 @@ conduct_rpc (void **rpcbuf, int **pp) return err; } -/* Dedicated thread to wakeup rpc_wakeup once a second. */ +/* Dedicated thread to signal those waiting on rpc_wakeup + once a second. */ void timeout_service_thread () { @@ -333,48 +359,52 @@ timeout_service_thread () void rpc_receive_thread () { - int cc; void *buf; - struct rpc_list *r; - int xid; + + /* Allocate a receive buffer */ + buf = malloc (1024 + read_size); + assert (buf); while (1) { - buf = malloc (1024 + read_size); - - do - { - cc = read (main_udp_socket, buf, 1024 + read_size); - if (cc == -1) - { - perror ("nfs read"); - r = 0; + int cc = read (main_udp_socket, buf, 1024 + read_size); + if (cc == -1) + { + perror ("nfs read"); + continue; + } + else + { + struct rpc_list *r; + int xid = *(int *)buf; + + mutex_lock (&outstanding_lock); + + /* Find the rpc that we just fulfilled */ + for (r = outstanding_rpcs; r; r = r->next) + { + if (* (int *) &r[1] == xid) + { + unlink_rpc (r); + r->reply = buf; + condition_broadcast (&rpc_wakeup); + break; + } } - else - { - xid = *(int *)buf; - mutex_lock (&outstanding_lock); - for (r = outstanding_rpcs; r; r = r->next) - { - if (* (int *) &r[1] == xid) - { - /* Remove it from the list */ - *r->prevp = r->next; - if (r->next) - r->next->prevp = r->prevp; - - r->reply = buf; - condition_broadcast (&rpc_wakeup); - break; - } - } -#if notanymore - if (!r) - fprintf (stderr, "NFS dropping reply xid %d\n", xid); +#if 0 + if (! r) + fprintf (stderr, "NFS dropping reply xid %d\n", xid); #endif - mutex_unlock (&outstanding_lock); + mutex_unlock (&outstanding_lock); + + /* If r is not null then we had a message from a pending + (i.e. known) rpc. Thus, it was fulfilled and if we + want to get another request, a new buffer is needed */ + if (r) + { + buf = malloc (1024 + read_size); + assert (buf); } - } - while (!r); + } } } |