OpenPKG Specs: openpkg/openpkg.c@a2c6460cfb16 (annotated)

openpkg/openpkg.c@a2c6460cfb16 (annotated)

openpkg/openpkg.c

Mon, 28 Jan 2013 17:37:18 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Mon, 28 Jan 2013 17:37:18 +0100
changeset 758: a2c6460cfb16
permissions: -rw-r--r--

Correct socket error reporting improvement with IPv6 portable code,
after helpful recommendation by Saúl Ibarra Corretgé on OSips devlist.

 /*
 **  openpkg.c -- OpenPKG Frontend
 **  Copyright (c) 2000-2012 OpenPKG GmbH <http://openpkg.com/>
 **
 **  This software is property of the OpenPKG GmbH, DE MUC HRB 160208.
 **  All rights reserved. Licenses which grant limited permission to use,
 **  copy, modify and distribute this software are available from the
 **  OpenPKG GmbH.
 **
 **  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 **  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 **  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 **  IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR
 **  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 **  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 **  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 **  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 **  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 **  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 **  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 **  SUCH DAMAGE.
 */
 /* program information */
 #define LICENSE \
     "Copyright (c) 2000-2012 OpenPKG GmbH <http://openpkg.com/>\n" \
     "\n" \
     "This software is property of the OpenPKG GmbH, DE MUC HRB 160208.\n" \
     "All rights reserved. Licenses which grant limited permission to use,\n" \
     "copy, modify and distribute this software are available from the\n" \
     "OpenPKG GmbH.\n" \
     "\n" \
     "THIS SOFTWARE IS PROVIDED \"AS IS\" AND ANY EXPRESSED OR IMPLIED\n" \
     "WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF\n" \
     "MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n" \
     "IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR\n" \
     "CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,\n" \
     "SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT\n" \
     "LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF\n" \
     "USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND\n" \
     "ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,\n" \
     "OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT\n" \
     "OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF\n" \
     "SUCH DAMAGE.\n"
 /* system includes */
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <pwd.h>
 #include <grp.h>
 #include <unistd.h>
 #include <errno.h>
 /* sanity check compilation */
 #ifndef OPENPKG_PREFIX
 #error OpenPKG instance prefix not defined
 #endif
 #ifndef OPENPKG_SUSR
 #error OpenPKG super user not defined
 #endif
 #ifndef OPENPKG_MUSR
 #error OpenPKG management user not defined
 #endif
 /* platform specifics */
 #if defined(OPENPKG_PLATFORM_FREEBSD) || \
     defined(OPENPKG_PLATFORM_NETBSD)  || \
     defined(OPENPKG_PLATFORM_OPENBSD) || \
     defined(OPENPKG_PLATFORM_SUNOS)   || \
     defined(OPENPKG_PLATFORM_LINUX)   || \
     defined(OPENPKG_PLATFORM_DARWIN)  || \
     defined(OPENPKG_PLATFORM_AIX)     || \
     defined(OPENPKG_PLATFORM_IRIX)    || \
     defined(OPENPKG_PLATFORM_HPUX)
 #define HAVE_INITGROUPS
 #endif
 /* global debug enable flag */
 static int debug_enable = 0;
 /* helper function: emulate (still less portable) setenv(3) via (more portable) putenv(3) */
 static int my_setenv(const char *name, const char *value, int overwrite)
 {
     char *pair;
     if (overwrite == 0 && getenv(name) != NULL)
         return 0;
     if ((pair = malloc(strlen(name) + 1 + strlen(value) + 1)) == NULL)
         return -1;
     strcpy(pair, name);
     strcat(pair, "=");
     strcat(pair, value);
     putenv(pair);
     return 0;
 }
 /* helper function for printing a warning message */
 static void warn(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
     fprintf(stderr, "openpkg:WARNING: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
     va_end(ap);
     return;
 }
 /* helper function for printing a debug message */
 static void debug(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
     if (debug_enable) {
         fprintf(stderr, "openpkg:DEBUG: ");
         vfprintf(stderr, fmt, ap);
         fprintf(stderr, "\n");
     }
     va_end(ap);
     return;
 }
 /* helper function for printing a fatal message and exit */
 static void fatal(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
     fprintf(stderr, "openpkg:ERROR: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
     va_end(ap);
     exit(1);
     return;
 }
 /* adjust process privileges */
 static void adjust_privileges(uid_t uid, gid_t gid, int login)
 {
     struct passwd *pw;
     char cwd[MAXPATHLEN];
     /* optionally emulate a more complete login */
     if (login) {
         /* determine information about user id */
         if ((pw = getpwuid(uid)) == NULL)
             fatal("unable to resolve user id \"%d\": %s", uid, strerror(errno));
         /* reset some essential environment variables */
         my_setenv("LOGNAME", pw->pw_name,   1);
         my_setenv("USER",    pw->pw_name,   1);
         my_setenv("SHELL",   pw->pw_shell,  1);
         my_setenv("HOME",    pw->pw_dir,    1);
 #ifdef HAVE_INITGROUPS
         /* initialize complete group access list */
         if (initgroups(pw->pw_name, pw->pw_gid) == -1)
             fatal("failed to initialize access group list via initgroups(3): %s", strerror(errno));
 #endif
     }
     /* switch to group id (first) */
     if (setgid(gid) == -1)
         fatal("failed to set group id via setgid(2): %s", strerror(errno));
     /* switch to user id (second) */
     if (setuid(uid) == -1)
         fatal("failed to set user id via setuid(2): %s", strerror(errno));
     /* in case the current working directory is NO LONGER accessible,
        try to switch to the home directory of the target identity to
        prevent failures in subsequently called programs (e.g. GNU bash) */
     if (login) {
         if (getcwd(cwd, sizeof(cwd)) == NULL) {
             warn("current working directory is no longer accessible -- switching to \"%s\"", pw->pw_dir);
             if (chdir(pw->pw_dir) == -1)
                 fatal("unable to chdir(2) to \"%s\": %s", pw->pw_dir, strerror(errno));
         }
     }
     return;
 }
 /* check whether caller is an explictly configured management user */
 static int check_whether_is_manager(uid_t my_uid, gid_t my_gid, uid_t m_uid, gid_t m_gid)
 {
     char buf[1024];
     char *username;
     char *groupname;
     char *filename;
     struct stat sb;
     char *cp;
     FILE *fp;
     struct passwd *pw;
     struct group *gr;
     int i;
     int ok_uid;
     int ok_gid;
     int is_manager;
     is_manager = 0;
     /* path to the managers configuration file */
     filename = OPENPKG_PREFIX "/etc/openpkg/managers";
     /* check permissions of file */
     if (stat(filename, &sb) == -1) {
         warn("unable to determine information about configuration"
              " file \"%s\": %s -- ignoring file", filename, strerror(errno));
         return 0;
     }
     if (sb.st_uid != m_uid) {
         warn("invalid owner user id %d (expected %d) on configuration"
              " file \"%s\" -- ignoring file", sb.st_uid, m_uid, filename);
         return 0;
     }
     if (sb.st_gid != m_gid) {
         warn("invalid owner group id %d (expected %d) on configuration"
              " file \"%s\" -- ignoring file", sb.st_gid, m_gid, filename);
         return 0;
     }
     if (sb.st_mode != (S_IFREG|S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH)) {
         warn("invalid permissions on configuration"
              " file \"%s\" -- ignoring file", filename);
         return 0;
     }
     /* parse configuration file */
     if ((fp = fopen(filename, "r")) == NULL) {
         warn("unable to open configuration file \"%s\": %s -- ignoring file", filename, strerror(errno));
         return 0;
     }
     while ((cp = fgets(buf, sizeof(buf), fp)) != NULL) {
         /* parse entry as "<username>[:<groupname>]" where both
            <username> and <groupname> can be set and default to "*"
            to indicate an arbitrary user or group */
         if ((i = strlen(buf)) == 0) {
             warn("unexpected empty buffer during parsing of configuration file \"%\"", filename);
             break;
         }
         if (i >= sizeof(buf)) {
             warn("unexpected buffer overflow during parsing of configuration file \"%\"", filename);
             break;
         }
         if (buf[i-1] != '\r' && buf[i-1] != '\n') {
             warn("unexpected non-newline-terminated line found during parsing of configuration file \"%\"", filename);
             break;
         }
         username = buf + strspn(buf, " \t");
         cp = username + strcspn(username, " \t#\r\n");
         *cp = '\0';
         if (username[0] == '#' || username[0] == '\r' || username[0] == '\n' || username[0] == '\0')
             continue;
         groupname = "*";
         if ((cp = strchr(username, ':')) != NULL) {
             *cp++ = '\0';
             groupname = cp;
         }
         debug("parsing result: username=\"%s\" groupname=\"%s\"", username, groupname);
         /* check whether UID is ok */
         ok_uid = 0;
         if (strcmp(username, "*") == 0)
             ok_uid = 1;
         else {
             if ((pw = getpwnam(username)) == NULL) {
                 warn("invalid username \"%s\" in \"%s\"", username, filename);
                 continue;
             }
             if (pw->pw_uid == my_uid)
                 ok_uid = 1;
         }
         /* check whether GID is ok */
         ok_gid = 0;
         if (strcmp(groupname, "*") == 0)
             ok_gid = 1;
         else {
             if ((gr = getgrnam(groupname)) == NULL) {
                 warn("invalid groupname \"%s\" in \"%s\"", groupname, filename);
                 continue;
             }
             if (gr->gr_gid == my_gid)
                 ok_gid = 1;
         }
         /* if both UID and GID are ok, user is manager */
         debug("matching: username ok = %s, groupname ok = %s", ok_uid ? "yes" : "no", ok_gid ? "yes" : "no");
         if (ok_uid && ok_gid) {
             is_manager = 1;
             break;
         }
     }
     fclose(fp);
     return is_manager;
 }
 /* check whether command requires super-user privileges */
 static int check_whether_require_superuser(int argc, char *argv[])
 {
     int require_superuser;
     int i, j;
     require_superuser = 0;
     if (argc > 1 && strcmp(argv[1], "rpm") == 0) {
         for (i = 2; i < argc; i++) {
             if (strcmp(argv[i], "--") == 0)
                 break;
             else if (   strcmp(argv[i], "--erase")      == 0
                      || strcmp(argv[i], "--freshen")    == 0
                      || strcmp(argv[i], "--install")    == 0
                      || strcmp(argv[i], "--upgrade")    == 0
                      || strcmp(argv[i], "--import")     == 0
                      || strcmp(argv[i], "--initdb")     == 0
                      || strcmp(argv[i], "--rebuilddb")  == 0
                      || strcmp(argv[i], "--db-build")   == 0
                      || strcmp(argv[i], "--db-rebuild") == 0
                      || strcmp(argv[i], "--db-cleanup") == 0
                      || strcmp(argv[i], "--db-fixate")  == 0
                      || strcmp(argv[i], "--setperms")   == 0
                      || strcmp(argv[i], "--setugids")   == 0) {
                 require_superuser = 1;
                 break;
             }
             else if (   argv[i][0] == '-'
                      && argv[i][1] != '-'
                      && argv[i][1] != 'b'
                      && argv[i][1] != 't'
                 ) {
                 for (j = 1; argv[i][j] != '\0'; j++) {
                     if (    (   argv[i][j] == 'q'
                              || argv[i][j] == 'K')
                          && argv[i][j+1] != '\0') {
                         j++;
                         continue;
                     }
                     else if (   argv[i][j] == 'i'
                         || argv[i][j] == 'U'
                         || argv[i][j] == 'F'
                         || argv[i][j] == 'V'
                         || argv[i][j] == 'e') {
                         require_superuser = 1;
                         break;
                     }
                 }
                 if (require_superuser)
                     break;
             }
         }
     }
     else if (argc > 1 && strcmp(argv[1], "rc") == 0) {
         require_superuser = 1;
         for (i = 2; i < argc; i++) {
             if (strcmp(argv[i], "--") == 0)
                 break;
             else if (   strcmp(argv[i], "-p")       == 0
                      || strcmp(argv[i], "--print")  == 0
                      || strcmp(argv[i], "-e")       == 0
                      || strcmp(argv[i], "--eval")   == 0
                      || strcmp(argv[i], "-q")       == 0
                      || strcmp(argv[i], "--query")  == 0
                      || strcmp(argv[i], "-c")       == 0
                      || strcmp(argv[i], "--config") == 0) {
                 require_superuser = 0;
                 break;
             }
         }
     }
     return require_superuser;
 }
 /* main program */
 int main(int argc, char **argv, char **envp)
 {
     int keep_original_privileges;
     int is_manager;
     int require_superuser;
     uid_t my_uid, my_euid;
     gid_t my_gid, my_egid;
     uid_t m_uid;
     gid_t m_gid;
     uid_t s_uid;
     gid_t s_gid;
     struct passwd *pw;
     struct group *gr;
     int dry_run;
     int license;
     /* parse command line options */
     license = 0;
     dry_run = 0;
     keep_original_privileges = 0;
     if (argc <= 0)
         abort();
     argv++; argc--;
     while (argc > 0) {
         if (argv[0][0] != '-')
             break;
         else if (strcmp(argv[0], "--") == 0) {
             argv++; argc--;
             break;
         }
         else if (strcmp(argv[0], "--license") == 0) {
             license = 1;
             argv++; argc--;
             continue;
         }
         else if (strcmp(argv[0], "--debug") == 0) {
             debug_enable = 1;
             argv++; argc--;
             continue;
         }
         else if (strcmp(argv[0], "--dry-run") == 0) {
             dry_run = 1;
             argv++; argc--;
             continue;
         }
         else if (strcmp(argv[0], "--keep-privileges") == 0) {
             keep_original_privileges = 1;
             argv++; argc--;
             continue;
         }
         break;
     }
     argv--; argc++;
     /* display stand-alone license information */
     if (license) {
         fprintf(stdout, "%s", LICENSE);
         exit(0);
     }
     /* determine our current real and effective user/group ids */
     my_uid  = getuid();
     my_gid  = getgid();
     my_euid = geteuid();
     my_egid = getegid();
     if ((pw = getpwuid(my_uid)) == NULL)
         fatal("unable to resolve current user id %d: %s", my_uid, strerror(errno));
     if ((gr = getgrgid(my_gid)) == NULL)
         fatal("unable to resolve current group id %d: %s", my_gid, strerror(errno));
     debug("current-user: usr=%s uid=%d euid=%d grp=%s gid=%d egid=%d",
           pw->pw_name, my_uid, my_euid, gr->gr_name, my_gid, my_egid);
     /* determine super user/group id */
     if ((pw = getpwnam(OPENPKG_SUSR)) == NULL)
         fatal("unable to resolve OpenPKG superuser username \"%s\": %s", OPENPKG_SUSR, strerror(errno));
     s_uid = pw->pw_uid;
     s_gid = pw->pw_gid;
     debug("super-user: s_usr=%s s_uid=%d s_gid=%d", OPENPKG_SUSR, s_uid, s_gid);
     /* determine management user/group id */
     if ((pw = getpwnam(OPENPKG_MUSR)) == NULL)
         fatal("unable to resolve OpenPKG management username \"%s\": %s", OPENPKG_MUSR, strerror(errno));
     m_uid = pw->pw_uid;
     m_gid = pw->pw_gid;
     debug("management-user: m_grp=%s m_uid=%d m_gid=%d", OPENPKG_MUSR, m_uid, m_gid);
     /* determine whether caller is explicitly configured as a management user */
     is_manager = 0;
     if (!keep_original_privileges)
         is_manager = check_whether_is_manager(my_uid, my_gid, m_uid, m_gid);
     debug("current user is manager: %s", is_manager ? "yes" : "no");
     /* determine whether command requires super-user privileges */
     require_superuser = check_whether_require_superuser(argc, argv);
     debug("current command requires super user privileges: %s", require_superuser ? "yes" : "no");
     /* adjust privileges according to determined information */
     if (!keep_original_privileges && require_superuser && is_manager && my_euid == 0) {
         /* increase privileges to super user */
         debug("increase privileges to super user");
         adjust_privileges(s_uid, s_gid, 1);
     }
     else if (!keep_original_privileges && !require_superuser && is_manager && my_euid == 0) {
         /* decrease privileges to management user */
         debug("decrease privileges to management user");
         adjust_privileges(m_uid, m_gid, 1);
     }
     else /* keep_original_privileges || !is_manager */ {
         /* drop effective privileges for current user*/
         debug("drop effective privileges for current user");
         adjust_privileges(my_uid, my_gid, 0);
     }
     /* pass-through control to real Execution Frontend (shell script) */
     argv[0] = OPENPKG_PREFIX "/lib/openpkg/openpkg";
     debug("execute \"%s\"", argv[0]);
     if (!dry_run) {
         if (execve(argv[0], argv, envp) == -1)
             fatal("failed to execute \"%s\": %s", argv[0], strerror(errno));
         /* NOT REACHED */
         fatal("INTERNAL ERROR");
     }
     return 0;
 }

OpenPKG Specs / annotate

openpkg/openpkg.c@a2c6460cfb16 (annotated)

openpkg/openpkg.c