1 /* getmountlist.c - Get a linked list of mount points, with stat information. 2 * 3 * Copyright 2006 Rob Landley <rob (at) landley.net> 4 */ 5 6 #include "toys.h" 7 #include <mntent.h> 8 9 // Traverse arg_list of csv, calling callback on each value 10 void comma_args(struct arg_list *al, void *data, char *err, 11 char *(*callback)(void *data, char *str, int len)) 12 { 13 char *next, *arg; 14 int len; 15 16 if (CFG_TOYBOX_DEBUG && !err) err = "INTERNAL"; 17 18 while (al) { 19 arg = al->arg; 20 while ((next = comma_iterate(&arg, &len))) 21 if ((next = callback(data, next, len))) 22 error_exit("%s '%s'\n%*c", err, al->arg, 23 (int)(5+strlen(toys.which->name)+strlen(err)+next-al->arg), '^'); 24 al = al->next; 25 } 26 } 27 28 // Realloc *old with oldstring,newstring 29 30 void comma_collate(char **old, char *new) 31 { 32 char *temp, *atold = *old; 33 34 // Only add a comma if old string didn't end with one 35 if (atold && *atold) { 36 char *comma = ","; 37 38 if (atold[strlen(atold)-1] == ',') comma = ""; 39 temp = xmprintf("%s%s%s", atold, comma, new); 40 } else temp = xstrdup(new); 41 free (atold); 42 *old = temp; 43 } 44 45 // iterate through strings in a comma separated list. 46 // returns start of next entry or NULL if none 47 // sets *len to length of entry (not including comma) 48 // advances *list to start of next entry 49 char *comma_iterate(char **list, int *len) 50 { 51 char *start = *list, *end; 52 53 if (!*list || !**list) return 0; 54 55 if (!(end = strchr(*list, ','))) { 56 *len = strlen(*list); 57 *list = 0; 58 } else *list += (*len = end-start)+1; 59 60 return start; 61 } 62 63 static void octal_deslash(char *s) 64 { 65 char *o = s; 66 67 while (*s) { 68 if (*s == '\\') { 69 int i, oct = 0; 70 71 for (i = 1; i < 4; i++) { 72 if (!isdigit(s[i])) break; 73 oct = (oct<<3)+s[i]-'0'; 74 } 75 if (i == 4) { 76 *o++ = oct; 77 s += i; 78 continue; 79 } 80 } 81 *o++ = *s++; 82 } 83 84 *o = 0; 85 } 86 87 // check all instances of opt and "no"opt in optlist, return true if opt 88 // found and last instance wasn't no. If clean, remove each instance from list. 89 int comma_scan(char *optlist, char *opt, int clean) 90 { 91 int optlen = strlen(opt), len, no, got = 0; 92 93 if (optlist) for (;;) { 94 char *s = comma_iterate(&optlist, &len); 95 96 if (!s) break; 97 no = 2*(*s == 'n' && s[1] == 'o'); 98 if (optlen == len-no && !strncmp(opt, s+no, optlen)) { 99 got = !no; 100 if (clean) { 101 if (optlist) memmove(s, optlist, strlen(optlist)+1); 102 else *s = 0; 103 } 104 } 105 } 106 107 return got; 108 } 109 110 // return true if all scanlist options enabled in optlist 111 int comma_scanall(char *optlist, char *scanlist) 112 { 113 int i = 1; 114 115 while (scanlist && *scanlist) { 116 char *opt = comma_iterate(&scanlist, &i), *s = xstrndup(opt, i); 117 118 i = comma_scan(optlist, s, 0); 119 free(s); 120 if (!i) break; 121 } 122 123 return i; 124 } 125 126 // Check if this type matches list. 127 // Odd syntax: typelist all yes = if any, typelist all no = if none. 128 129 int mountlist_istype(struct mtab_list *ml, char *typelist) 130 { 131 int len, skip; 132 char *t; 133 134 if (!typelist) return 1; 135 136 skip = strncmp(typelist, "no", 2); 137 138 for (;;) { 139 if (!(t = comma_iterate(&typelist, &len))) break; 140 if (!skip) { 141 // If one -t starts with "no", the rest must too 142 if (strncmp(t, "no", 2)) error_exit("bad typelist"); 143 if (!strncmp(t+2, ml->type, len-2)) { 144 skip = 1; 145 break; 146 } 147 } else if (!strncmp(t, ml->type, len) && !ml->type[len]) { 148 skip = 0; 149 break; 150 } 151 } 152 153 return !skip; 154 } 155 156 // Get list of mounted filesystems, including stat and statvfs info. 157 // Returns a reversed list, which is good for finding overmounts and such. 158 159 struct mtab_list *xgetmountlist(char *path) 160 { 161 struct mtab_list *mtlist = 0, *mt; 162 struct mntent *me; 163 FILE *fp; 164 char *p = path ? path : "/proc/mounts"; 165 166 if (!(fp = setmntent(p, "r"))) perror_exit("bad %s", p); 167 168 // The "test" part of the loop is done before the first time through and 169 // again after each "increment", so putting the actual load there avoids 170 // duplicating it. If the load was NULL, the loop stops. 171 172 while ((me = getmntent(fp))) { 173 mt = xzalloc(sizeof(struct mtab_list) + strlen(me->mnt_fsname) + 174 strlen(me->mnt_dir) + strlen(me->mnt_type) + strlen(me->mnt_opts) + 4); 175 dlist_add_nomalloc((void *)&mtlist, (void *)mt); 176 177 // Collect details about mounted filesystem 178 // Don't report errors, just leave data zeroed 179 if (!path) { 180 stat(me->mnt_dir, &(mt->stat)); 181 statvfs(me->mnt_dir, &(mt->statvfs)); 182 } 183 184 // Remember information from /proc/mounts 185 mt->dir = stpcpy(mt->type, me->mnt_type)+1; 186 mt->device = stpcpy(mt->dir, me->mnt_dir)+1; 187 mt->opts = stpcpy(mt->device, me->mnt_fsname)+1; 188 strcpy(mt->opts, me->mnt_opts); 189 190 octal_deslash(mt->dir); 191 octal_deslash(mt->device); 192 } 193 endmntent(fp); 194 195 return mtlist; 196 } 197
