ref: ca8ca008f4ab7074971a35e08de9a46cb9b5d5ab
dir: /sys/src/cmd/upas/common/libsys.c/
#include "common.h" #include <auth.h> #include <ndb.h> /* * number of predefined fd's */ int nsysfile=3; static char err[Errlen]; /* * return the date */ extern char * thedate(void) { static char now[64]; char *cp; strcpy(now, ctime(time(0))); cp = strchr(now, '\n'); if(cp) *cp = 0; return now; } /* * return the user id of the current user */ extern char * getlog(void) { static char user[64]; int fd; int n; fd = open("/dev/user", 0); if(fd < 0) return nil; if((n=read(fd, user, sizeof(user)-1)) <= 0) return nil; close(fd); user[n] = 0; return user; } /* * return the lock name (we use one lock per directory) */ static String * lockname(char *path) { String *lp; char *cp; /* * get the name of the lock file */ lp = s_new(); cp = strrchr(path, '/'); if(cp) s_nappend(lp, path, cp - path + 1); s_append(lp, "L.mbox"); return lp; } int syscreatelocked(char *path, int mode, int perm) { return create(path, mode, DMEXCL|perm); } int sysopenlocked(char *path, int mode) { /* return open(path, OEXCL|mode);/**/ return open(path, mode); /* until system call is fixed */ } int sysunlockfile(int fd) { return close(fd); } /* * try opening a lock file. If it doesn't exist try creating it. */ static int openlockfile(Mlock *l) { int fd; Dir *d; Dir nd; char *p; fd = open(s_to_c(l->name), OREAD); if(fd >= 0){ l->fd = fd; return 0; } d = dirstat(s_to_c(l->name)); if(d == nil){ /* file doesn't exist */ /* try creating it */ fd = create(s_to_c(l->name), OREAD, DMEXCL|0666); if(fd >= 0){ nulldir(&nd); nd.mode = DMEXCL|0666; if(dirfwstat(fd, &nd) < 0){ /* if we can't chmod, don't bother */ /* live without the lock but log it */ syslog(0, "mail", "lock error: %s: %r", s_to_c(l->name)); remove(s_to_c(l->name)); } l->fd = fd; return 0; } /* couldn't create */ /* do we have write access to the directory? */ p = strrchr(s_to_c(l->name), '/'); if(p != 0){ *p = 0; fd = access(s_to_c(l->name), 2); *p = '/'; if(fd < 0){ /* live without the lock but log it */ syslog(0, "mail", "lock error: %s: %r", s_to_c(l->name)); return 0; } } else { fd = access(".", 2); if(fd < 0){ /* live without the lock but log it */ syslog(0, "mail", "lock error: %s: %r", s_to_c(l->name)); return 0; } } } else free(d); return 1; /* try again later */ } #define LSECS 5*60 /* * Set a lock for a particular file. The lock is a file in the same directory * and has L. prepended to the name of the last element of the file name. */ extern Mlock * syslock(char *path) { Mlock *l; int tries; l = mallocz(sizeof(Mlock), 1); if(l == 0) return nil; l->name = lockname(path); /* * wait LSECS seconds for it to unlock */ for(tries = 0; tries < LSECS*2; tries++){ switch(openlockfile(l)){ case 0: return l; case 1: sleep(500); break; default: goto noway; } } noway: s_free(l->name); free(l); return nil; } /* * like lock except don't wait */ extern Mlock * trylock(char *path) { Mlock *l; char buf[1]; int fd; l = malloc(sizeof(Mlock)); if(l == 0) return 0; l->name = lockname(path); if(openlockfile(l) != 0){ s_free(l->name); free(l); return 0; } /* fork process to keep lock alive */ switch(l->pid = rfork(RFPROC)){ default: break; case 0: fd = l->fd; for(;;){ sleep(1000*60); if(pread(fd, buf, 1, 0) < 0) break; } _exits(0); } return l; } extern void syslockrefresh(Mlock *l) { char buf[1]; pread(l->fd, buf, 1, 0); } extern void sysunlock(Mlock *l) { if(l == 0) return; if(l->name){ s_free(l->name); } if(l->fd >= 0) close(l->fd); if(l->pid > 0) postnote(PNPROC, l->pid, "time to die"); free(l); } /* * Open a file. The modes are: * * l - locked * a - set append permissions * r - readable * w - writable * A - append only (doesn't exist in Bio) */ extern Biobuf * sysopen(char *path, char *mode, ulong perm) { int sysperm; int sysmode; int fd; int docreate; int append; int truncate; Dir *d, nd; Biobuf *bp; /* * decode the request */ sysperm = 0; sysmode = -1; docreate = 0; append = 0; truncate = 0; for(; mode && *mode; mode++) switch(*mode){ case 'A': sysmode = OWRITE; append = 1; break; case 'c': docreate = 1; break; case 'l': sysperm |= DMEXCL; break; case 'a': sysperm |= DMAPPEND; break; case 'w': if(sysmode == -1) sysmode = OWRITE; else sysmode = ORDWR; break; case 'r': if(sysmode == -1) sysmode = OREAD; else sysmode = ORDWR; break; case 't': truncate = 1; break; default: break; } switch(sysmode){ case OREAD: case OWRITE: case ORDWR: break; default: if(sysperm&DMAPPEND) sysmode = OWRITE; else sysmode = OREAD; break; } /* * create file if we need to */ if(truncate) sysmode |= OTRUNC; fd = open(path, sysmode); if(fd < 0){ d = dirstat(path); if(d == nil){ if(docreate == 0) return 0; fd = create(path, sysmode, sysperm|perm); if(fd < 0) return 0; nulldir(&nd); nd.mode = sysperm|perm; dirfwstat(fd, &nd); } else { free(d); return 0; } } bp = (Biobuf*)malloc(sizeof(Biobuf)); if(bp == 0){ close(fd); return 0; } memset(bp, 0, sizeof(Biobuf)); Binit(bp, fd, sysmode&~OTRUNC); if(append) Bseek(bp, 0, 2); return bp; } /* * close the file, etc. */ int sysclose(Biobuf *bp) { int rv; rv = Bterm(bp); close(Bfildes(bp)); free(bp); return rv; } /* * create a file */ int syscreate(char *file, int mode, ulong perm) { return create(file, mode, perm); } /* * make a directory */ int sysmkdir(char *file, ulong perm) { int fd; if((fd = create(file, OREAD, DMDIR|perm)) < 0) return -1; close(fd); return 0; } /* * change the group of a file */ int syschgrp(char *file, char *group) { Dir nd; if(group == 0) return -1; nulldir(&nd); nd.gid = group; return dirwstat(file, &nd); } extern int sysdirreadall(int fd, Dir **d) { return dirreadall(fd, d); } /* * read in the system name */ extern char * sysname_read(void) { static char name[128]; char *cp; cp = getenv("site"); if(cp == 0 || *cp == 0) cp = alt_sysname_read(); if(cp == 0 || *cp == 0) cp = "kremvax"; strecpy(name, name+sizeof name, cp); return name; } extern char * alt_sysname_read(void) { static char name[128]; int n, fd; fd = open("/dev/sysname", OREAD); if(fd < 0) return 0; n = read(fd, name, sizeof(name)-1); close(fd); if(n <= 0) return 0; name[n] = 0; return name; } /* * get all names */ extern char** sysnames_read(void) { static char **namev; Ndbtuple *t, *nt; int n; char *cp; if(namev) return namev; free(csgetvalue(0, "sys", alt_sysname_read(), "dom", &t)); n = 0; for(nt = t; nt; nt = nt->entry) if(strcmp(nt->attr, "dom") == 0) n++; namev = (char**)malloc(sizeof(char *)*(n+3)); if(namev){ n = 0; namev[n++] = strdup(sysname_read()); cp = alt_sysname_read(); if(cp) namev[n++] = strdup(cp); for(nt = t; nt; nt = nt->entry) if(strcmp(nt->attr, "dom") == 0) namev[n++] = strdup(nt->val); namev[n] = 0; } if(t) ndbfree(t); return namev; } /* * read in the domain name */ extern char * domainname_read(void) { char **namev; for(namev = sysnames_read(); *namev; namev++) if(strchr(*namev, '.')) return *namev; return 0; } /* * return true if the last error message meant file * did not exist. */ extern int e_nonexistent(void) { rerrstr(err, sizeof(err)); return strcmp(err, "file does not exist") == 0; } /* * return true if the last error message meant file * was locked. */ extern int e_locked(void) { rerrstr(err, sizeof(err)); return strcmp(err, "open/create -- file is locked") == 0; } /* * return the length of a file */ extern long sysfilelen(Biobuf *fp) { Dir *d; long rv; d = dirfstat(Bfildes(fp)); if(d == nil) return -1; rv = d->length; free(d); return rv; } /* * remove a file */ extern int sysremove(char *path) { return remove(path); } /* * rename a file, fails unless both are in the same directory */ extern int sysrename(char *old, char *new) { Dir d; char *obase; char *nbase; obase = strrchr(old, '/'); nbase = strrchr(new, '/'); if(obase){ if(nbase == 0) return -1; if(strncmp(old, new, obase-old) != 0) return -1; nbase++; } else { if(nbase) return -1; nbase = new; } nulldir(&d); d.name = nbase; return dirwstat(old, &d); } /* * see if a file exists */ extern int sysexist(char *file) { Dir *d; d = dirstat(file); if(d == nil) return 0; free(d); return 1; } /* * return nonzero if file is a directory */ extern int sysisdir(char *file) { Dir *d; int rv; d = dirstat(file); if(d == nil) return 0; rv = d->mode & DMDIR; free(d); return rv; } /* * kill a process or process group */ static int stomp(int pid, char *file) { char name[64]; int fd; snprint(name, sizeof(name), "/proc/%d/%s", pid, file); fd = open(name, 1); if(fd < 0) return -1; if(write(fd, "die: yankee pig dog\n", sizeof("die: yankee pig dog\n") - 1) <= 0){ close(fd); return -1; } close(fd); return 0; } /* * kill a process */ extern int syskill(int pid) { return stomp(pid, "note"); } /* * kill a process group */ extern int syskillpg(int pid) { return stomp(pid, "notepg"); } extern int sysdetach(void) { if(rfork(RFENVG|RFNAMEG|RFNOTEG) < 0) { werrstr("rfork failed"); return -1; } return 0; } /* * catch a write on a closed pipe */ static int *closedflag; static int catchpipe(void *a, char *msg) { static char *foo = "sys: write on closed pipe"; USED(a); if(strncmp(msg, foo, strlen(foo)) == 0){ if(closedflag) *closedflag = 1; return 1; } return 0; } void pipesig(int *flagp) { closedflag = flagp; atnotify(catchpipe, 1); } void pipesigoff(void) { atnotify(catchpipe, 0); } void exit(int i) { char buf[32]; if(i == 0) exits(0); snprint(buf, sizeof(buf), "%d", i); exits(buf); } static int islikeatty(int fd) { char buf[64]; if(fd2path(fd, buf, sizeof buf) != 0) return 0; /* might be /mnt/term/dev/cons */ return strlen(buf) >= 9 && strcmp(buf+strlen(buf)-9, "/dev/cons") == 0; } extern int holdon(void) { int fd; if(!islikeatty(0)) return -1; fd = open("/dev/consctl", OWRITE); write(fd, "holdon", 6); return fd; } extern int sysopentty(void) { return open("/dev/cons", ORDWR); } extern void holdoff(int fd) { write(fd, "holdoff", 7); close(fd); } extern int sysfiles(void) { return 128; } /* * expand a path relative to the user's mailbox directory * * if the path starts with / or ./, don't change it * */ extern String * mboxpath(char *path, char *user, String *to, int dot) { if (dot || *path=='/' || strncmp(path, "./", 2) == 0 || strncmp(path, "../", 3) == 0) { to = s_append(to, path); } else { to = s_append(to, MAILROOT); to = s_append(to, "/box/"); to = s_append(to, user); to = s_append(to, "/"); to = s_append(to, path); } return to; } extern String * mboxname(char *user, String *to) { return mboxpath("mbox", user, to, 0); } extern String * deadletter(String *to) /* pass in sender??? */ { char *cp; cp = getlog(); if(cp == 0) return 0; return mboxpath("dead.letter", cp, to, 0); } char * homedir(char *user) { USED(user); return getenv("home"); } String * readlock(String *file) { char *cp; cp = getlog(); if(cp == 0) return 0; return mboxpath("reading", cp, file, 0); } String * username(String *from) { int n; Biobuf *bp; char *p, *q; String *s; bp = Bopen("/adm/keys.who", OREAD); if(bp == 0) bp = Bopen("/adm/netkeys.who", OREAD); if(bp == 0) return 0; s = 0; n = strlen(s_to_c(from)); for(;;) { p = Brdline(bp, '\n'); if(p == 0) break; p[Blinelen(bp)-1] = 0; if(strncmp(p, s_to_c(from), n)) continue; p += n; if(*p != ' ' && *p != '\t') /* must be full match */ continue; while(*p && (*p == ' ' || *p == '\t')) p++; if(*p == 0) continue; for(q = p; *q; q++) if(('0' <= *q && *q <= '9') || *q == '<') break; while(q > p && q[-1] != ' ' && q[-1] != '\t') q--; while(q > p && (q[-1] == ' ' || q[-1] == '\t')) q--; *q = 0; s = s_new(); s_append(s, "\""); s_append(s, p); s_append(s, "\""); break; } Bterm(bp); return s; } char * remoteaddr(int fd, char *dir) { char buf[128], *p; int n; if(dir == 0){ if(fd2path(fd, buf, sizeof(buf)) != 0) return ""; /* parse something of the form /net/tcp/nnnn/data */ p = strrchr(buf, '/'); if(p == 0) return ""; strncpy(p+1, "remote", sizeof(buf)-(p-buf)-2); } else snprint(buf, sizeof buf, "%s/remote", dir); buf[sizeof(buf)-1] = 0; fd = open(buf, OREAD); if(fd < 0) return ""; n = read(fd, buf, sizeof(buf)-1); close(fd); if(n > 0){ buf[n] = 0; p = strchr(buf, '!'); if(p) *p = 0; return strdup(buf); } return ""; } // create a file and // 1) ensure the modes we asked for // 2) make gid == uid static int docreate(char *file, int perm) { int fd; Dir ndir; Dir *d; // create the mbox fd = create(file, OREAD, perm); if(fd < 0){ fprint(2, "couldn't create %s\n", file); return -1; } d = dirfstat(fd); if(d == nil){ fprint(2, "couldn't stat %s\n", file); return -1; } nulldir(&ndir); ndir.mode = perm; ndir.gid = d->uid; if(dirfwstat(fd, &ndir) < 0) fprint(2, "couldn't chmod %s: %r\n", file); close(fd); return 0; } // create a mailbox int creatembox(char *user, char *folder) { char *p; String *mailfile; char buf[512]; Mlock *ml; mailfile = s_new(); if(folder == 0) mboxname(user, mailfile); else { snprint(buf, sizeof(buf), "%s/mbox", folder); mboxpath(buf, user, mailfile, 0); } // don't destroy existing mailbox if(access(s_to_c(mailfile), 0) == 0){ fprint(2, "mailbox already exists\n"); return -1; } fprint(2, "creating new mbox: %s\n", s_to_c(mailfile)); // make sure preceding levels exist for(p = s_to_c(mailfile); p; p++) { if(*p == '/') /* skip leading or consecutive slashes */ continue; p = strchr(p, '/'); if(p == 0) break; *p = 0; if(access(s_to_c(mailfile), 0) != 0){ if(docreate(s_to_c(mailfile), DMDIR|0711) < 0) return -1; } *p = '/'; } // create the mbox if(docreate(s_to_c(mailfile), 0622|DMAPPEND|DMEXCL) < 0) return -1; /* * create the lock file if it doesn't exist */ ml = trylock(s_to_c(mailfile)); if(ml != nil) sysunlock(ml); return 0; }