#! execs

[unix-history] / usr / src / sys / kern / kern_proc.c

diff --git a/usr/src/sys/kern/kern_proc.c b/usr/src/sys/kern/kern_proc.c
index 266e2c4..f9fedea 100644 (file)
--- a/usr/src/sys/kern/kern_proc.c
+++ b/usr/src/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*     kern_proc.c     4.2     %G%     */
+/*     kern_proc.c     4.3     %G%     */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -42,13 +42,28 @@ exece()
        register struct buf *bp;
        register struct execa *uap;
        int na, ne, ucp, ap, c;
        register struct buf *bp;
        register struct execa *uap;
        int na, ne, ucp, ap, c;

+       int indir, uid, gid;
+       char *sharg;

        struct inode *ip;
        swblk_t bno;
        struct inode *ip;
        swblk_t bno;

+       char cfname[DIRSIZ];
+       char cfarg[SHSIZE];

 
        if ((ip = namei(uchar, 0)) == NULL)
                return;
 
        if ((ip = namei(uchar, 0)) == NULL)
                return;

+

        bno = 0;
        bp = 0;
        bno = 0;
        bp = 0;

+       indir = 0;
+       uid = u.u_uid;
+       gid = u.u_gid;
+
+       if (ip->i_mode & ISUID)
+               uid = ip->i_uid;
+       if (ip->i_mode & ISGID)
+               gid = ip->i_gid;
+
+  again:

        if(access(ip, IEXEC))
                goto bad;
        if((ip->i_mode & IFMT) != IFREG ||
        if(access(ip, IEXEC))
                goto bad;
        if((ip->i_mode & IFMT) != IFREG ||


@@ -56,6 +71,95 @@ exece()
                u.u_error = EACCES;
                goto bad;
        }
                u.u_error = EACCES;
                goto bad;
        }

+
+       /*
+        * Read in first few bytes of file for segment sizes, ux_mag:
+        *      407 = plain executable
+        *      410 = RO text
+        *      413 = demand paged RO text
+        * Also an ASCII line beginning with #! is
+        * the file name of a ``shell'' and arguments may be prepended
+        * to the argument list if given here.
+        *
+        * SHELL NAMES ARE LIMITED IN LENGTH.
+        *
+        * ONLY ONE ARGUMENT MAY BE PASSED TO THE SHELL FROM
+        * THE ASCII LINE.
+        */
+       u.u_base = (caddr_t)&u.u_exdata;
+       u.u_count = sizeof(u.u_exdata);
+       u.u_offset = 0;
+       u.u_segflg = 1;
+       readi(ip);
+       u.u_segflg = 0;
+       if(u.u_error)
+               goto bad;
+       if (u.u_count > sizeof(u.u_exdata) - sizeof(u.u_exdata.Ux_A)
+               && u.u_exdata.ux_shell[0] != '#') {
+               u.u_error = ENOEXEC;
+               goto bad;
+       }
+       switch (u.u_exdata.ux_mag) {
+
+       case 0407:
+               u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
+               u.u_exdata.ux_tsize = 0;
+               break;
+
+       case 0413:
+       case 0410:
+               if (u.u_exdata.ux_tsize == 0) {
+                       u.u_error = ENOEXEC;
+                       goto bad;
+               }
+               break;
+
+       default:
+               if (u.u_exdata.ux_shell[0] != '#' ||
+                   u.u_exdata.ux_shell[1] != '!' ||
+                   indir) {
+                       u.u_error = ENOEXEC;
+                       goto bad;
+               }
+               cp = &u.u_exdata.ux_shell[2];           /* skip "#!" */
+               while (cp < &u.u_exdata.ux_shell[SHSIZE]) {
+                       if (*cp == '\t')
+                               *cp = ' ';
+                       else if (*cp == '\n') {
+                               *cp = '\0';
+                               break;
+                       }
+                       cp++;
+               }
+               if (*cp != '\0') {
+                       u.u_error = ENOEXEC;
+                       goto bad;
+               }
+               cp = &u.u_exdata.ux_shell[2];
+               while (*cp == ' ')
+                       cp++;
+               u.u_dirp = cp;
+               while (*cp && *cp != ' ')
+                       cp++;
+               sharg = NULL;
+               if (*cp) {
+                       *cp++ = '\0';
+                       while (*cp == ' ')
+                               cp++;
+                       if (*cp) {
+                               bcopy((caddr_t)cp, (caddr_t)cfarg, SHSIZE);
+                               sharg = cfarg;
+                       }
+               }
+               bcopy((caddr_t)u.u_dbuf, (caddr_t)cfname, DIRSIZ);
+               indir = 1;
+               iput(ip);
+               ip = namei(schar, 0);
+               if (ip == NULL)
+                       return;
+               goto again;
+       }
+

        /*
         * Collect arguments on "file" in swap space.
         */
        /*
         * Collect arguments on "file" in swap space.
         */


@@ -71,7 +175,12 @@ exece()
                panic("execa malloc");
        if (uap->argp) for (;;) {
                ap = NULL;
                panic("execa malloc");
        if (uap->argp) for (;;) {
                ap = NULL;

-               if (uap->argp) {
+               if (na == 1 && indir) {
+                       if (sharg == NULL)
+                               ap = (int)uap->fname;
+               } else if (na == 2 && indir && sharg != NULL)
+                       ap = (int)uap->fname;
+               else if (uap->argp) {

                        ap = fuword((caddr_t)uap->argp);
                        uap->argp++;
                }
                        ap = fuword((caddr_t)uap->argp);
                        uap->argp++;
                }


@@ -90,7 +199,9 @@ exece()
                do {
                        if (nc >= NCARGS-1)
                                u.u_error = E2BIG;
                do {
                        if (nc >= NCARGS-1)
                                u.u_error = E2BIG;

-                       if ((c = fubyte((caddr_t)ap++)) < 0)
+                       if (indir && na == 2 && sharg != NULL)
+                               c = *sharg++ & 0377;
+                       else if ((c = fubyte((caddr_t)ap++)) < 0)

                                u.u_error = EFAULT;
                        if (u.u_error) {
                                if (bp)
                                u.u_error = EFAULT;
                        if (u.u_error) {
                                if (bp)


@@ -113,7 +224,9 @@ exece()
                bdwrite(bp);
        bp = 0;
        nc = (nc + NBPW-1) & ~(NBPW-1);
                bdwrite(bp);
        bp = 0;
        nc = (nc + NBPW-1) & ~(NBPW-1);

-       getxfile(ip, nc + (na+4)*NBPW);
+       if (indir)
+               bcopy((caddr_t)cfname, (caddr_t)u.u_dbuf, DIRSIZ);
+       getxfile(ip, nc + (na+4)*NBPW, uid, gid);

        if (u.u_error) {
 badarg:
                for (c = 0; c < nc; c += BSIZE)
        if (u.u_error) {
 badarg:
                for (c = 0; c < nc; c += BSIZE)


@@ -172,56 +285,17 @@ bad:
 /*
  * Read in and set up memory for executed file.
  */
 /*
  * Read in and set up memory for executed file.
  */

-getxfile(ip, nargc)
+getxfile(ip, nargc, uid, gid)

 register struct inode *ip;
 {
        register size_t ts, ds, ss;
 register struct inode *ip;
 {
        register size_t ts, ds, ss;

-       int pagi = 0;
-
-       /*
-        * read in first few bytes
-        * of file for segment
-        * sizes:
-        * ux_mag = 407/410/413
-        *  407 is plain executable
-        *  410 is RO text
-        *  413 is demand paged RO text
-        */
-
-       u.u_base = (caddr_t)&u.u_exdata;
-       u.u_count = sizeof(u.u_exdata);
-       u.u_offset = 0;
-       u.u_segflg = 1;
-       readi(ip);
-       u.u_segflg = 0;
-       if(u.u_error)
-               goto bad;
-       if (u.u_count!=0) {
-               u.u_error = ENOEXEC;
-               goto bad;
-       }
-       switch (u.u_exdata.ux_mag) {
-
-       case 0407:
-               u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
-               u.u_exdata.ux_tsize = 0;
-               break;
+       int pagi;

 
 

-       case 0413:
+       if (u.u_exdata.ux_mag == 0413)

                pagi = SPAGI;
                pagi = SPAGI;

-               /* fall into ... */
-
-       case 0410:
-               if (u.u_exdata.ux_tsize == 0) {
-                       u.u_error = ENOEXEC;
-                       goto bad;
-               }
-               break;
+       else
+               pagi = 0;

 
 

-       default:
-               u.u_error = ENOEXEC;
-               goto bad;
-       }

        if(u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 && ip->i_count!=1) {
                register struct file *fp;
 
        if(u.u_exdata.ux_tsize!=0 && (ip->i_flag&ITEXT)==0 && ip->i_count!=1) {
                register struct file *fp;
 


@@ -295,13 +369,14 @@ register struct inode *ip;
         * set SUID/SGID protections, if no tracing
         */
        if ((u.u_procp->p_flag&STRC)==0) {
         * set SUID/SGID protections, if no tracing
         */
        if ((u.u_procp->p_flag&STRC)==0) {

-               if(ip->i_mode&ISUID)
-                       if(u.u_uid != 0) {
-                               u.u_uid = ip->i_uid;
-                               u.u_procp->p_uid = ip->i_uid;
-                       }
-               if(ip->i_mode&ISGID)
-                       u.u_gid = ip->i_gid;
+#ifndef        MELB
+               if(u.u_uid != 0)
+#endif
+               {
+                       u.u_uid = uid;
+                       u.u_procp->p_uid = uid;
+               }
+               u.u_gid = gid;

        } else
                psignal(u.u_procp, SIGTRAP);
        u.u_tsize = ts;
        } else
                psignal(u.u_procp, SIGTRAP);
        u.u_tsize = ts;


@@ -608,13 +683,14 @@ fork1(isvfork)
                                a++;
                }
        }
                                a++;
                }
        }

+

        /*
         * Disallow if
         *  No processes at all;
         *  not su and too many procs owned; or
         *  not su and would take last slot.
         */
        /*
         * Disallow if
         *  No processes at all;
         *  not su and too many procs owned; or
         *  not su and would take last slot.
         */

-       if (p2==NULL || (u.u_uid!=0 && (p2==&proc[NPROC-1] || a>MAXUPRC))) {
+       if (p2==NULL || (u.u_uid!=0 && (p2>=&proc[NPROC-5] || a>MAXUPRC))) {

                u.u_error = EAGAIN;
                if (!isvfork) {
                        (void) vsexpand(0, &u.u_cdmap, 1);
                u.u_error = EAGAIN;
                if (!isvfork) {
                        (void) vsexpand(0, &u.u_cdmap, 1);