Contents of /trunk/mkinitrd-magellan/klibc/usr/kinit/nfsmount/dummypmap.c
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Revision 1297 -
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Fri May 27 15:12:11 2011 UTC (12 years, 11 months ago) by niro
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File size: 5797 byte(s)
Fri May 27 15:12:11 2011 UTC (12 years, 11 months ago) by niro
File MIME type: text/plain
File size: 5797 byte(s)
-updated to klibc-1.5.22 with mntproc definitions patch included
1 | /* |
2 | * Enough portmapper functionality that mount doesn't hang trying |
3 | * to start lockd. Enables nfsroot with locking functionality. |
4 | * |
5 | * Note: the kernel will only speak to the local portmapper |
6 | * using RPC over UDP. |
7 | */ |
8 | |
9 | #include <sys/types.h> |
10 | #include <netinet/in.h> |
11 | #include <stdio.h> |
12 | #include <stdlib.h> |
13 | #include <errno.h> |
14 | #include <unistd.h> |
15 | #include <string.h> |
16 | #include <sys/socket.h> |
17 | |
18 | #include "dummypmap.h" |
19 | #include "sunrpc.h" |
20 | |
21 | extern const char *progname; |
22 | |
23 | struct portmap_args { |
24 | uint32_t program; |
25 | uint32_t version; |
26 | uint32_t proto; |
27 | uint32_t port; |
28 | }; |
29 | |
30 | struct portmap_call { |
31 | struct rpc_call rpc; |
32 | struct portmap_args args; |
33 | }; |
34 | |
35 | struct portmap_reply { |
36 | struct rpc_reply rpc; |
37 | uint32_t port; |
38 | }; |
39 | |
40 | static int bind_portmap(void) |
41 | { |
42 | int sock = socket(PF_INET, SOCK_DGRAM, 0); |
43 | struct sockaddr_in sin; |
44 | |
45 | if (sock < 0) |
46 | return -1; |
47 | |
48 | memset(&sin, 0, sizeof sin); |
49 | sin.sin_family = AF_INET; |
50 | sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */ |
51 | sin.sin_port = htons(RPC_PMAP_PORT); |
52 | if (bind(sock, (struct sockaddr *)&sin, sizeof sin) < 0) { |
53 | int err = errno; |
54 | close(sock); |
55 | errno = err; |
56 | return -1; |
57 | } |
58 | |
59 | return sock; |
60 | } |
61 | |
62 | static const char *protoname(uint32_t proto) |
63 | { |
64 | switch (ntohl(proto)) { |
65 | case IPPROTO_TCP: |
66 | return "tcp"; |
67 | case IPPROTO_UDP: |
68 | return "udp"; |
69 | default: |
70 | return NULL; |
71 | } |
72 | } |
73 | |
74 | static void * get_auth(struct rpc_auth *auth) |
75 | { |
76 | switch (ntohl(auth->flavor)) { |
77 | case AUTH_NULL: |
78 | /* Fallthrough */ |
79 | case AUTH_UNIX: |
80 | return (char *)&auth->body + ntohl(auth->len); |
81 | default: |
82 | return NULL; |
83 | } |
84 | } |
85 | |
86 | static int check_unix_cred(struct rpc_auth *cred) |
87 | { |
88 | uint32_t len; |
89 | int quad_len; |
90 | uint32_t node_name_len; |
91 | int quad_name_len; |
92 | uint32_t *base; |
93 | uint32_t *pos; |
94 | int ret = -1; |
95 | |
96 | len = ntohl(cred->len); |
97 | quad_len = (len + 3) >> 2; |
98 | if (quad_len < 6) |
99 | /* Malformed creds */ |
100 | goto out; |
101 | |
102 | base = pos = cred->body; |
103 | |
104 | /* Skip timestamp */ |
105 | pos++; |
106 | |
107 | /* Skip node name: only localhost can succeed. */ |
108 | node_name_len = ntohl(*pos++); |
109 | quad_name_len = (node_name_len + 3) >> 2; |
110 | if (pos + quad_name_len + 3 > base + quad_len) |
111 | /* Malformed creds */ |
112 | goto out; |
113 | pos += quad_name_len; |
114 | |
115 | /* uid must be 0 */ |
116 | if (*pos++ != 0) |
117 | goto out; |
118 | |
119 | /* gid must be 0 */ |
120 | if (*pos++ != 0) |
121 | goto out; |
122 | |
123 | /* Skip remaining gids */ |
124 | ret = 0; |
125 | |
126 | out: |
127 | return ret; |
128 | } |
129 | |
130 | static int check_cred(struct rpc_auth *cred) |
131 | { |
132 | switch (ntohl(cred->flavor)) { |
133 | case AUTH_NULL: |
134 | return 0; |
135 | case AUTH_UNIX: |
136 | return check_unix_cred(cred); |
137 | default: |
138 | return -1; |
139 | } |
140 | } |
141 | |
142 | static int check_vrf(struct rpc_auth *vrf) |
143 | { |
144 | return (vrf->flavor == htonl(AUTH_NULL)) ? 0 : -1; |
145 | } |
146 | |
147 | static int dummy_portmap(int sock, FILE *portmap_file) |
148 | { |
149 | struct sockaddr_in sin; |
150 | int pktlen, addrlen; |
151 | unsigned char pkt[65536]; /* Max UDP packet size */ |
152 | /* RPC UDP packets do not include TCP fragment size */ |
153 | struct rpc_call *rpc = (struct rpc_call *) &pkt[-4]; |
154 | struct rpc_auth *cred; |
155 | struct rpc_auth *vrf; |
156 | struct portmap_args *args; |
157 | struct portmap_reply rply; |
158 | |
159 | for (;;) { |
160 | addrlen = sizeof sin; |
161 | pktlen = recvfrom(sock, &pkt, sizeof pkt, 0, |
162 | (struct sockaddr *)&sin, &addrlen); |
163 | |
164 | if (pktlen < 0) { |
165 | if (errno == EINTR) |
166 | continue; |
167 | |
168 | return -1; |
169 | } |
170 | |
171 | /* +4 to skip the TCP fragment header */ |
172 | if (pktlen + 4 < sizeof(struct portmap_call)) |
173 | continue; /* Bad packet */ |
174 | |
175 | if (rpc->hdr.udp.msg_type != htonl(RPC_CALL)) |
176 | continue; /* Bad packet */ |
177 | |
178 | memset(&rply, 0, sizeof rply); |
179 | |
180 | rply.rpc.hdr.udp.xid = rpc->hdr.udp.xid; |
181 | rply.rpc.hdr.udp.msg_type = htonl(RPC_REPLY); |
182 | |
183 | cred = (struct rpc_auth *) &rpc->cred_flavor; |
184 | if (rpc->rpc_vers != htonl(2)) { |
185 | rply.rpc.reply_state = htonl(REPLY_DENIED); |
186 | /* state <- RPC_MISMATCH == 0 */ |
187 | } else if (rpc->program != htonl(PORTMAP_PROGRAM)) { |
188 | rply.rpc.reply_state = htonl(PROG_UNAVAIL); |
189 | } else if (rpc->prog_vers != htonl(2)) { |
190 | rply.rpc.reply_state = htonl(PROG_MISMATCH); |
191 | } else if (!(vrf = get_auth(cred)) || |
192 | (char *)vrf > (char *)pkt + pktlen - 8 - sizeof(*args) || |
193 | !(args = get_auth(vrf)) || |
194 | (char *)args > (char *)pkt + pktlen - sizeof(*args) || |
195 | check_cred(cred) || check_vrf(vrf)) { |
196 | /* Can't deal with credentials data; the kernel |
197 | won't send them */ |
198 | rply.rpc.reply_state = htonl(SYSTEM_ERR); |
199 | } else { |
200 | switch (ntohl(rpc->proc)) { |
201 | case PMAP_PROC_NULL: |
202 | break; |
203 | case PMAP_PROC_SET: |
204 | if (args->proto == htonl(IPPROTO_TCP) || |
205 | args->proto == htonl(IPPROTO_UDP)) { |
206 | if (portmap_file) |
207 | fprintf(portmap_file, |
208 | "%u %u %s %u\n", |
209 | ntohl(args->program), |
210 | ntohl(args->version), |
211 | protoname(args->proto), |
212 | ntohl(args->port)); |
213 | rply.port = htonl(1); /* TRUE = success */ |
214 | } |
215 | break; |
216 | case PMAP_PROC_UNSET: |
217 | rply.port = htonl(1); /* TRUE = success */ |
218 | break; |
219 | case PMAP_PROC_GETPORT: |
220 | break; |
221 | case PMAP_PROC_DUMP: |
222 | break; |
223 | default: |
224 | rply.rpc.reply_state = htonl(PROC_UNAVAIL); |
225 | break; |
226 | } |
227 | } |
228 | |
229 | sendto(sock, &rply.rpc.hdr.udp, sizeof rply - 4, 0, |
230 | (struct sockaddr *)&sin, addrlen); |
231 | } |
232 | } |
233 | |
234 | pid_t start_dummy_portmap(const char *file) |
235 | { |
236 | FILE *portmap_filep; |
237 | int sock; |
238 | pid_t spoof_portmap; |
239 | |
240 | portmap_filep = fopen(file, "w"); |
241 | if (!portmap_filep) { |
242 | fprintf(stderr, "%s: cannot write portmap file: %s\n", |
243 | progname, file); |
244 | return -1; |
245 | } |
246 | |
247 | sock = bind_portmap(); |
248 | if (sock == -1) { |
249 | if (errno == EINVAL || errno == EADDRINUSE) |
250 | return 0; /* Assume not needed */ |
251 | else { |
252 | fclose(portmap_filep); |
253 | fprintf(stderr, "%s: portmap spoofing failed\n", |
254 | progname); |
255 | return -1; |
256 | } |
257 | } |
258 | |
259 | spoof_portmap = fork(); |
260 | if (spoof_portmap == -1) { |
261 | fclose(portmap_filep); |
262 | fprintf(stderr, "%s: cannot fork\n", progname); |
263 | return -1; |
264 | } else if (spoof_portmap == 0) { |
265 | /* Child process */ |
266 | dummy_portmap(sock, portmap_filep); |
267 | _exit(255); /* Error */ |
268 | } else { |
269 | /* Parent process */ |
270 | close(sock); |
271 | return spoof_portmap; |
272 | } |
273 | } |