]>
Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de> |
3 | * | |
4 | * Allow an NFS filesystem to be mounted as root. The way this works is: | |
5 | * (1) Use the IP autoconfig mechanism to set local IP addresses and routes. | |
56463e50 CL |
6 | * (2) Construct the device string and the options string using DHCP |
7 | * option 17 and/or kernel command line options. | |
8 | * (3) When mount_root() sets up the root file system, pass these strings | |
9 | * to the NFS client's regular mount interface via sys_mount(). | |
1da177e4 LT |
10 | * |
11 | * | |
12 | * Changes: | |
13 | * | |
14 | * Alan Cox : Removed get_address name clash with FPU. | |
15 | * Alan Cox : Reformatted a bit. | |
16 | * Gero Kuhlmann : Code cleanup | |
17 | * Michael Rausch : Fixed recognition of an incoming RARP answer. | |
18 | * Martin Mares : (2.0) Auto-configuration via BOOTP supported. | |
19 | * Martin Mares : Manual selection of interface & BOOTP/RARP. | |
20 | * Martin Mares : Using network routes instead of host routes, | |
21 | * allowing the default configuration to be used | |
22 | * for normal operation of the host. | |
23 | * Martin Mares : Randomized timer with exponential backoff | |
24 | * installed to minimize network congestion. | |
25 | * Martin Mares : Code cleanup. | |
26 | * Martin Mares : (2.1) BOOTP and RARP made configuration options. | |
27 | * Martin Mares : Server hostname generation fixed. | |
28 | * Gerd Knorr : Fixed wired inode handling | |
29 | * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored. | |
30 | * Martin Mares : RARP replies not tested for server address. | |
31 | * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please | |
32 | * send me your new patches _before_ bothering | |
33 | * Linus so that I don' always have to cleanup | |
34 | * _afterwards_ - thanks) | |
35 | * Gero Kuhlmann : Last changes of Martin Mares undone. | |
36 | * Gero Kuhlmann : RARP replies are tested for specified server | |
37 | * again. However, it's now possible to have | |
38 | * different RARP and NFS servers. | |
39 | * Gero Kuhlmann : "0.0.0.0" addresses from command line are | |
40 | * now mapped to INADDR_NONE. | |
41 | * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name | |
42 | * from being used (thanks to Leo Spiekman) | |
43 | * Andy Walker : Allow to specify the NFS server in nfs_root | |
44 | * without giving a path name | |
96de0e25 | 45 | * Swen Thümmler : Allow to specify the NFS options in nfs_root |
1da177e4 LT |
46 | * without giving a path name. Fix BOOTP request |
47 | * for domainname (domainname is NIS domain, not | |
48 | * DNS domain!). Skip dummy devices for BOOTP. | |
49 | * Jacek Zapala : Fixed a bug which prevented server-ip address | |
50 | * from nfsroot parameter from being used. | |
51 | * Olaf Kirch : Adapted to new NFS code. | |
52 | * Jakub Jelinek : Free used code segment. | |
53 | * Marko Kohtala : Fixed some bugs. | |
54 | * Martin Mares : Debug message cleanup | |
55 | * Martin Mares : Changed to use the new generic IP layer autoconfig | |
56 | * code. BOOTP and RARP moved there. | |
57 | * Martin Mares : Default path now contains host name instead of | |
58 | * host IP address (but host name defaults to IP | |
59 | * address anyway). | |
60 | * Martin Mares : Use root_server_addr appropriately during setup. | |
61 | * Martin Mares : Rewrote parameter parsing, now hopefully giving | |
62 | * correct overriding. | |
63 | * Trond Myklebust : Add in preliminary support for NFSv3 and TCP. | |
64 | * Fix bug in root_nfs_addr(). nfs_data.namlen | |
65 | * is NOT for the length of the hostname. | |
66 | * Hua Qin : Support for mounting root file system via | |
67 | * NFS over TCP. | |
68 | * Fabian Frederick: Option parser rebuilt (using parser lib) | |
56463e50 | 69 | * Chuck Lever : Use super.c's text-based mount option parsing |
306a0753 | 70 | * Chuck Lever : Add "nfsrootdebug". |
56463e50 | 71 | */ |
1da177e4 | 72 | |
1da177e4 LT |
73 | #include <linux/types.h> |
74 | #include <linux/string.h> | |
1da177e4 | 75 | #include <linux/init.h> |
1da177e4 LT |
76 | #include <linux/nfs.h> |
77 | #include <linux/nfs_fs.h> | |
1da177e4 | 78 | #include <linux/utsname.h> |
1da177e4 LT |
79 | #include <linux/root_dev.h> |
80 | #include <net/ipconfig.h> | |
1da177e4 | 81 | |
146ec944 CL |
82 | #include "internal.h" |
83 | ||
1da177e4 LT |
84 | #define NFSDBG_FACILITY NFSDBG_ROOT |
85 | ||
86 | /* Default path we try to mount. "%s" gets replaced by our IP address */ | |
87 | #define NFS_ROOT "/tftpboot/%s" | |
88 | ||
53d47375 | 89 | /* Default NFSROOT mount options. */ |
4251c948 | 90 | #define NFS_DEF_OPTIONS "vers=2,udp,rsize=4096,wsize=4096" |
53d47375 | 91 | |
1da177e4 | 92 | /* Parameters passed from the kernel command line */ |
60ac0368 | 93 | static char nfs_root_parms[256] __initdata = ""; |
1da177e4 | 94 | |
56463e50 | 95 | /* Text-based mount options passed to super.c */ |
53d47375 | 96 | static char nfs_root_options[256] __initdata = NFS_DEF_OPTIONS; |
56463e50 | 97 | |
1da177e4 | 98 | /* Address of NFS server */ |
8d232103 | 99 | static __be32 servaddr __initdata = htonl(INADDR_NONE); |
1da177e4 LT |
100 | |
101 | /* Name of directory to mount */ | |
56463e50 CL |
102 | static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = ""; |
103 | ||
104 | /* server:export path string passed to super.c */ | |
105 | static char nfs_root_device[NFS_MAXPATHLEN + 1] __initdata = ""; | |
1da177e4 | 106 | |
e27d359e | 107 | #ifdef NFS_DEBUG |
306a0753 CL |
108 | /* |
109 | * When the "nfsrootdebug" kernel command line option is specified, | |
110 | * enable debugging messages for NFSROOT. | |
111 | */ | |
112 | static int __init nfs_root_debug(char *__unused) | |
113 | { | |
114 | nfs_debug |= NFSDBG_ROOT | NFSDBG_MOUNT; | |
115 | return 1; | |
116 | } | |
117 | ||
118 | __setup("nfsrootdebug", nfs_root_debug); | |
036a1075 | 119 | #endif |
306a0753 | 120 | |
1da177e4 LT |
121 | /* |
122 | * Parse NFS server and directory information passed on the kernel | |
123 | * command line. | |
60ac0368 CL |
124 | * |
125 | * nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>] | |
126 | * | |
127 | * If there is a "%s" token in the <root-dir> string, it is replaced | |
128 | * by the ASCII-representation of the client's IP address. | |
1da177e4 LT |
129 | */ |
130 | static int __init nfs_root_setup(char *line) | |
131 | { | |
132 | ROOT_DEV = Root_NFS; | |
60ac0368 | 133 | |
1da177e4 | 134 | if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { |
60ac0368 | 135 | strlcpy(nfs_root_parms, line, sizeof(nfs_root_parms)); |
1da177e4 | 136 | } else { |
60ac0368 CL |
137 | size_t n = strlen(line) + sizeof(NFS_ROOT) - 1; |
138 | if (n >= sizeof(nfs_root_parms)) | |
139 | line[sizeof(nfs_root_parms) - sizeof(NFS_ROOT) - 2] = '\0'; | |
140 | sprintf(nfs_root_parms, NFS_ROOT, line); | |
1da177e4 | 141 | } |
60ac0368 CL |
142 | |
143 | /* | |
144 | * Extract the IP address of the NFS server containing our | |
145 | * root file system, if one was specified. | |
146 | * | |
147 | * Note: root_nfs_parse_addr() removes the server-ip from | |
148 | * nfs_root_parms, if it exists. | |
149 | */ | |
150 | root_server_addr = root_nfs_parse_addr(nfs_root_parms); | |
151 | ||
1da177e4 LT |
152 | return 1; |
153 | } | |
154 | ||
155 | __setup("nfsroot=", nfs_root_setup); | |
156 | ||
56463e50 CL |
157 | static int __init root_nfs_copy(char *dest, const char *src, |
158 | const size_t destlen) | |
159 | { | |
160 | if (strlcpy(dest, src, destlen) > destlen) | |
161 | return -1; | |
162 | return 0; | |
163 | } | |
164 | ||
165 | static int __init root_nfs_cat(char *dest, const char *src, | |
53d47375 | 166 | const size_t destlen) |
56463e50 | 167 | { |
53d47375 CL |
168 | size_t len = strlen(dest); |
169 | ||
170 | if (len && dest[len - 1] != ',') | |
171 | if (strlcat(dest, ",", destlen) > destlen) | |
172 | return -1; | |
173 | ||
56463e50 CL |
174 | if (strlcat(dest, src, destlen) > destlen) |
175 | return -1; | |
176 | return 0; | |
177 | } | |
178 | ||
179 | /* | |
180 | * Parse out root export path and mount options from | |
181 | * passed-in string @incoming. | |
182 | * | |
183 | * Copy the export path into @exppath. | |
184 | */ | |
185 | static int __init root_nfs_parse_options(char *incoming, char *exppath, | |
186 | const size_t exppathlen) | |
187 | { | |
188 | char *p; | |
189 | ||
190 | /* | |
191 | * Set the NFS remote path | |
192 | */ | |
193 | p = strsep(&incoming, ","); | |
194 | if (*p != '\0' && strcmp(p, "default") != 0) | |
195 | if (root_nfs_copy(exppath, p, exppathlen)) | |
196 | return -1; | |
197 | ||
198 | /* | |
199 | * @incoming now points to the rest of the string; if it | |
200 | * contains something, append it to our root options buffer | |
201 | */ | |
202 | if (incoming != NULL && *incoming != '\0') | |
203 | if (root_nfs_cat(nfs_root_options, incoming, | |
204 | sizeof(nfs_root_options))) | |
205 | return -1; | |
56463e50 CL |
206 | return 0; |
207 | } | |
208 | ||
209 | /* | |
210 | * Decode the export directory path name and NFS options from | |
211 | * the kernel command line. This has to be done late in order to | |
212 | * use a dynamically acquired client IP address for the remote | |
213 | * root directory path. | |
214 | * | |
215 | * Returns zero if successful; otherwise -1 is returned. | |
216 | */ | |
217 | static int __init root_nfs_data(char *cmdline) | |
218 | { | |
53d47375 | 219 | char mand_options[sizeof("nolock,addr=") + INET_ADDRSTRLEN + 1]; |
56463e50 CL |
220 | int len, retval = -1; |
221 | char *tmp = NULL; | |
222 | const size_t tmplen = sizeof(nfs_export_path); | |
223 | ||
224 | tmp = kzalloc(tmplen, GFP_KERNEL); | |
225 | if (tmp == NULL) | |
226 | goto out_nomem; | |
227 | strcpy(tmp, NFS_ROOT); | |
228 | ||
229 | if (root_server_path[0] != '\0') { | |
230 | dprintk("Root-NFS: DHCPv4 option 17: %s\n", | |
231 | root_server_path); | |
232 | if (root_nfs_parse_options(root_server_path, tmp, tmplen)) | |
233 | goto out_optionstoolong; | |
234 | } | |
235 | ||
236 | if (cmdline[0] != '\0') { | |
237 | dprintk("Root-NFS: nfsroot=%s\n", cmdline); | |
238 | if (root_nfs_parse_options(cmdline, tmp, tmplen)) | |
239 | goto out_optionstoolong; | |
240 | } | |
241 | ||
242 | /* | |
243 | * Append mandatory options for nfsroot so they override | |
244 | * what has come before | |
245 | */ | |
53d47375 | 246 | snprintf(mand_options, sizeof(mand_options), "nolock,addr=%pI4", |
56463e50 | 247 | &servaddr); |
53d47375 | 248 | if (root_nfs_cat(nfs_root_options, mand_options, |
56463e50 CL |
249 | sizeof(nfs_root_options))) |
250 | goto out_optionstoolong; | |
251 | ||
252 | /* | |
253 | * Set up nfs_root_device. For NFS mounts, this looks like | |
254 | * | |
255 | * server:/path | |
256 | * | |
257 | * At this point, utsname()->nodename contains our local | |
258 | * IP address or hostname, set by ipconfig. If "%s" exists | |
259 | * in tmp, substitute the nodename, then shovel the whole | |
260 | * mess into nfs_root_device. | |
261 | */ | |
262 | len = snprintf(nfs_export_path, sizeof(nfs_export_path), | |
263 | tmp, utsname()->nodename); | |
c7c545d4 | 264 | if (len >= (int)sizeof(nfs_export_path)) |
56463e50 CL |
265 | goto out_devnametoolong; |
266 | len = snprintf(nfs_root_device, sizeof(nfs_root_device), | |
267 | "%pI4:%s", &servaddr, nfs_export_path); | |
c7c545d4 | 268 | if (len >= (int)sizeof(nfs_root_device)) |
56463e50 CL |
269 | goto out_devnametoolong; |
270 | ||
271 | retval = 0; | |
272 | ||
273 | out: | |
274 | kfree(tmp); | |
275 | return retval; | |
276 | out_nomem: | |
277 | printk(KERN_ERR "Root-NFS: could not allocate memory\n"); | |
278 | goto out; | |
279 | out_optionstoolong: | |
280 | printk(KERN_ERR "Root-NFS: mount options string too long\n"); | |
281 | goto out; | |
282 | out_devnametoolong: | |
283 | printk(KERN_ERR "Root-NFS: root device name too long.\n"); | |
284 | goto out; | |
285 | } | |
286 | ||
287 | /** | |
288 | * nfs_root_data - Return prepared 'data' for NFSROOT mount | |
289 | * @root_device: OUT: address of string containing NFSROOT device | |
290 | * @root_data: OUT: address of string containing NFSROOT mount options | |
291 | * | |
292 | * Returns zero and sets @root_device and @root_data if successful, | |
293 | * otherwise -1 is returned. | |
294 | */ | |
295 | int __init nfs_root_data(char **root_device, char **root_data) | |
296 | { | |
56463e50 CL |
297 | servaddr = root_server_addr; |
298 | if (servaddr == htonl(INADDR_NONE)) { | |
299 | printk(KERN_ERR "Root-NFS: no NFS server address\n"); | |
300 | return -1; | |
301 | } | |
302 | ||
303 | if (root_nfs_data(nfs_root_parms) < 0) | |
304 | return -1; | |
305 | ||
306 | *root_device = nfs_root_device; | |
307 | *root_data = nfs_root_options; | |
308 | return 0; | |
309 | } |