3 // Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
4 // based on syscall.cc by Jacques Gelinas
6 // This program is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2, or (at your option)
11 // This program is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 This tells the system call number for new_s_context and set_ipv4root
22 using /proc/self/status. This helps until the vserver project is
23 included officially in the kernel (and has its own syscall).
25 We rely on /proc/self/status to find the syscall number.
27 If it is not there, we rely on adm/unistd.h.
29 If this file does not have those system calls (not a patched kernel source)
30 we rely on static values in this file.
32 #include "safechroot-internal.hc"
38 #include <asm/unistd.h>
41 // Here is the trick. We keep a copy of the define, then undef it
42 // and then later, we try to locate the value reading /proc/self/status
43 // If this fails, we have the old preserved copy.
44 static int def_NR_set_ipv4root = 274;
45 #undef __NR_set_ipv4root
47 static int __NR_set_ipv4root_rev0;
48 static int __NR_set_ipv4root_rev1;
49 static int __NR_set_ipv4root_rev2;
50 static int __NR_set_ipv4root_rev3;
51 static int rev_ipv4root=0;
54 static _syscall1(int, set_ipv4root_rev0, unsigned long, ip)
55 static _syscall2(int, set_ipv4root_rev1, unsigned long, ip, unsigned long, bcast)
56 static _syscall3(int, set_ipv4root_rev2, unsigned long *, ip, int, nb, unsigned long, bcast)
57 static _syscall4(int, set_ipv4root_rev3, unsigned long *, ip, int, nb, unsigned long, bcast, unsigned long *, mask)
59 static int def_NR_new_s_context = 273;
60 #undef __NR_new_s_context
61 static int __NR_new_s_context_rev0;
62 //static int __NR_new_s_context_rev1;
63 static int rev_s_context=0;
65 static _syscall3(int, new_s_context_rev0, int, newctx, int, remove_cap, int, flags)
66 //static _syscall4(int, new_s_context_rev1, int, nbctx, int *, ctxs, int, remove_cap, int, flags)
69 #undef __NR_set_ctxlimit
70 static int __NR_set_ctxlimit=-1;
71 static int rev_set_ctxlimit=-1;
73 static _syscall2 (int, set_ctxlimit, int, resource, long, limit)
76 #undef __NR_chrootsafe
77 static int __NR_chrootsafe=-1;
78 static int rev_chrootsafe=-1;
80 static _syscall1 (int, chrootsafe, const char *, dir)
82 static bool is_init = false;
84 #include "utils-legacy.h"
87 # define WRITE_MSG(FD,X) (void)(write(FD,X,sizeof(X)-1))
92 getNumRevPair(char const *str, int *num, int *rev)
94 char const * blank_pos = strchr(str, ' ');
95 char const * eol_pos = strchr(str, '\n');
98 if (*num==0) return false;
100 if (blank_pos!=0 && eol_pos!=0 && blank_pos<eol_pos &&
101 strncmp(blank_pos+1, "rev", 3)==0)
102 *rev = atoi(blank_pos+4);
107 #define SET_TAG_POS(TAG) \
108 pos = strstr(buf, (TAG)); \
109 if (pos) pos+=sizeof(TAG)-1
111 static bool init_internal()
113 size_t bufsize = utilvserver_getProcEntryBufsize();
115 char const * pos = 0;
116 pid_t pid = getpid();
121 pos=utilvserver_getProcEntry(pid, 0, buf, bufsize);
122 if (pos==0 && errno==EAGAIN) return false;
124 SET_TAG_POS("\n__NR_set_ipv4root: ");
125 if ( pos!=0 && getNumRevPair(pos, &num, &rev_ipv4root) ) {
126 __NR_set_ipv4root_rev0 =
127 __NR_set_ipv4root_rev1 =
128 __NR_set_ipv4root_rev2 =
129 __NR_set_ipv4root_rev3 = num;
133 SET_TAG_POS("\n__NR_set_ctxlimit: ");
134 if ( pos!=0 && getNumRevPair(pos, &num, &rev_set_ctxlimit) )
135 __NR_set_ctxlimit = num;
138 SET_TAG_POS("\n__NR_chrootsafe: ");
139 if ( pos!=0 && getNumRevPair(pos, &num, &rev_chrootsafe) )
140 __NR_chrootsafe = num;
142 SET_TAG_POS("\n__NR_new_s_context: ");
143 if ( pos!=0 && getNumRevPair(pos, &num, &rev_s_context) )
144 __NR_new_s_context_rev0 = num;
154 __NR_set_ipv4root_rev0 = def_NR_set_ipv4root;
155 __NR_set_ipv4root_rev1 = def_NR_set_ipv4root;
156 __NR_set_ipv4root_rev2 = def_NR_set_ipv4root;
157 __NR_set_ipv4root_rev3 = def_NR_set_ipv4root;
158 __NR_new_s_context_rev0 = def_NR_new_s_context;
160 while (!init_internal() && errno==EAGAIN) {}
166 void vc_init_legacy()
171 void vc_init_internal_legacy(int ctx_rev, int ctx_number,
172 int ipv4_rev, int ipv4_number)
174 rev_s_context = ctx_rev;
175 __NR_new_s_context_rev0 = ctx_number;
177 rev_ipv4root = ipv4_rev;
178 __NR_set_ipv4root_rev0 = ipv4_number;
179 __NR_set_ipv4root_rev1 = ipv4_number;
180 __NR_set_ipv4root_rev2 = ipv4_number;
181 __NR_set_ipv4root_rev3 = ipv4_number;
186 static ALWAYSINLINE int
187 vc_new_s_context_legacy(int ctx, int remove_cap, int flags)
191 if (rev_s_context == 0){
192 return new_s_context_rev0(ctx, remove_cap, flags);
200 static ALWAYSINLINE int
201 vc_set_ipv4root_legacy_internal (
205 unsigned long mask[])
208 if (rev_ipv4root == 0){
210 WRITE_MSG(2,"set_ipv4root: Several IP number specified, but this kernel only supports one. Ignored\n");
212 return set_ipv4root_rev0 (ip[0]);
213 }else if (rev_ipv4root == 1){
215 WRITE_MSG(2,"set_ipv4root: Several IP number specified, but this kernel only supports one. Ignored\n");
217 return set_ipv4root_rev1 (ip[0],bcast);
218 }else if (rev_ipv4root == 2){
219 return set_ipv4root_rev2 (ip,nb,bcast);
220 }else if (rev_ipv4root == 3){
221 return set_ipv4root_rev3 (ip,nb,bcast,mask);
227 static ALWAYSINLINE int
228 vc_set_ipv4root_legacy(uint32_t bcast, size_t nb, struct vc_ip_mask_pair const *ips)
230 unsigned long ip[nb];
231 unsigned long mask[nb];
234 for (i=0; i<nb; ++i) {
236 mask[i] = ips[i].mask;
239 return vc_set_ipv4root_legacy_internal(ip, nb, bcast, mask);
242 static ALWAYSINLINE int
243 vc_chrootsafe_legacy (const char *dir)
246 if (rev_chrootsafe == -1){
247 vc_tell_unsafe_chroot();
249 }else if (rev_chrootsafe == 0){
250 return chrootsafe (dir);
252 WRITE_MSG(2, "chrootsafe: kernel supports wrong version, application expects version 0\n");
260 Return != 0 if chrootsafe is available
265 return rev_chrootsafe != -1;
268 int call_set_ctxlimit (int res, long limit)
271 if (rev_set_ctxlimit == -1){
272 fprintf (stderr,"set_ctxlimit: Unsupported system call, update kernel\n");
273 }else if (rev_set_ctxlimit == 0){
274 return set_ctxlimit (res,limit);
276 fprintf (stderr,"set_ctxlimit: kernel support version %d, application expects version 0\n"