simplify parsing of /etc/busybox.conf

function                                             old     new   delta
parse_config_file                                    799     667    -132

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 30 insertions, 45 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 705829cb0..03f712821 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -236,8 +236,7 @@ IF_FEATURE_SUID(static uid_t ruid;)  /* real uid */
 /* applets[] is const, so we have to define this "override" structure */
 static struct BB_suid_config {
         int m_applet;
-        uid_t m_uid;
-        gid_t m_gid;
+        struct bb_uidgid_t m_ugid;
         mode_t m_mode;
         struct BB_suid_config *m_next;
 } *suid_config;
@@ -295,8 +294,6 @@ static const unsigned short mode_mask[] ALIGN2 = {
         0,          S_IXOTH,            S_IXOTH,    0   /* other */
 };
 
-#define parse_error(x)  do { errmsg = x; goto pe_label; } while (0)
-
 static void parse_config_file(void)
 {
         struct BB_suid_config *sct_head;
@@ -312,8 +309,6 @@ static void parse_config_file(void)
         char buffer[256];
         struct stat st;
 
-        assert(!suid_config); /* Should be set to NULL by bss init. */
-
         ruid = getuid();
         if (ruid == 0) /* run by root - don't need to even read config file */
                 return;
@@ -322,7 +317,7 @@ static void parse_config_file(void)
          || !S_ISREG(st.st_mode)                /* Not a regular file? */
          || (st.st_uid != 0)                    /* Not owned by root? */
          || (st.st_mode & (S_IWGRP | S_IWOTH))  /* Writable by non-root? */
-         || !(f = fopen_for_read(config_file))      /* Cannot open? */
+         || !(f = fopen_for_read(config_file))  /* Cannot open? */
         ) {
                 return;
         }
@@ -335,10 +330,11 @@ static void parse_config_file(void)
                 s = buffer;
 
                 if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
-// why?
-                        if (ferror(f)) {   /* Make sure it wasn't a read error. */
-                                parse_error("reading");
-                        }
+                        // Looks like bloat
+                        //if (ferror(f)) {   /* Make sure it wasn't a read error. */
+                        //      errmsg = "reading";
+                        //      goto pe_label;
+                        //}
                         fclose(f);
                         suid_config = sct_head; /* Success, so set the pointer. */
                         return;
@@ -355,7 +351,8 @@ static void parse_config_file(void)
                  * we do err on the side of caution.  Besides, the line would be
                  * too long if it did end with a newline. */
                 if (!strchr(s, '\n') && !feof(f)) {
-                        parse_error("line too long");
+                        errmsg = "line too long";
+                        goto pe_label;
                 }
 
                 /* Trim leading and trailing whitespace, ignoring comments, and
@@ -376,7 +373,8 @@ static void parse_config_file(void)
                          || e[1] /* Trailing characters? */
                          || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
                         ) {
-                                parse_error("section header");
+                                errmsg = "section header";
+                                goto pe_label;
                         }
                         /* Right now we only have one section so just check it.
                          * If more sections are added in the future, please don't
@@ -406,7 +404,8 @@ static void parse_config_file(void)
                                 s = get_trimmed_slice(s, e);
                         }
                         if (!e || !*s) {        /* Missing '=' or empty key. */
-                                parse_error("keyword");
+                                errmsg = "keyword";
+                                goto pe_label;
                         }
 
                         /* Ok, we have an applet name.  Process the rhs if this
@@ -419,9 +418,9 @@ static void parse_config_file(void)
                                  * The last config line for each applet will be the
                                  * one used since we insert at the head of the list.
                                  * I suppose this could be considered a feature. */
-                                sct = xmalloc(sizeof(struct BB_suid_config));
+                                sct = xzalloc(sizeof(*sct));
                                 sct->m_applet = applet_no;
-                                sct->m_mode = 0;
+                                /*sct->m_mode = 0;*/
                                 sct->m_next = sct_head;
                                 sct_head = sct;
 
@@ -436,7 +435,8 @@ static void parse_config_file(void)
                                         const char *q;
                                         q = strchrnul(mode_chars + 5*i, *e++);
                                         if (!*q) {
-                                                parse_error("mode");
+                                                errmsg = "mode";
+                                                goto pe_label;
                                         }
                                         /* Adjust by -i to account for nul. */
                                         sct->m_mode |= mode_mask[(q - mode_chars) - i];
@@ -449,29 +449,14 @@ static void parse_config_file(void)
                                 /* Note: we require whitespace between the mode and the
                                  * user/group info. */
                                 if ((s == e) || !(e = strchr(s, '.'))) {
-                                        parse_error("<uid>.<gid>");
-                                }
-                                *e++ = '\0';
-
-                                /* We can't use get_ug_id here since it would exit()
-                                 * if a uid or gid was not found.  Oh well... */
-                                sct->m_uid = bb_strtoul(s, NULL, 10);
-                                if (errno) {
-                                        struct passwd *pwd = getpwnam(s);
-                                        if (!pwd) {
-                                                parse_error("user");
-                                        }
-                                        sct->m_uid = pwd->pw_uid;
+                                        errmsg = "uid.gid";
+                                        goto pe_label;
                                 }
 
-                                sct->m_gid = bb_strtoul(e, NULL, 10);
-                                if (errno) {
-                                        struct group *grp;
-                                        grp = getgrnam(e);
-                                        if (!grp) {
-                                                parse_error("group");
-                                        }
-                                        sct->m_gid = grp->gr_gid;
+                                *e++ = ':'; /* get_uidgid doesn't understand user.group */
+                                if (get_uidgid(&sct->m_ugid, s, /*allow_numeric:*/ 1) == 0) {
+                                        errmsg = "unknown user/group";
+                                        goto pe_label;
                                 }
                         }
                         continue;
@@ -485,14 +470,14 @@ static void parse_config_file(void)
                  * We may want to simply ignore such lines in case they
                  * are used in some future version of busybox. */
                 if (!section) {
-                        parse_error("keyword outside section");
+                        errmsg = "keyword outside section";
+                        goto pe_label;
                 }
 
         } /* while (1) */
 
  pe_label:
-        fprintf(stderr, "Parse error in %s, line %d: %s\n",
-                        config_file, lc, errmsg);
+        bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
 
         fclose(f);
         /* Release any allocated memory before returning. */
@@ -532,10 +517,10 @@ static void check_suid(int applet_no)
                 goto check_need_suid;
  found:
                 m = sct->m_mode;
-                if (sct->m_uid == ruid)
+                if (sct->m_ugid.uid == ruid)
                         /* same uid */
                         m >>= 6;
-                else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid))
+                else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
                         /* same group / in group */
                         m >>= 3;
 
@@ -544,7 +529,7 @@ static void check_suid(int applet_no)
 
                 /* _both_ sgid and group_exec have to be set for setegid */
                 if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
-                        rgid = sct->m_gid;
+                        rgid = sct->m_ugid.gid;
                 /* else (no setegid) we will set egid = rgid */
 
                 /* We set effective AND saved ids. If saved-id is not set
@@ -555,7 +540,7 @@ static void check_suid(int applet_no)
                 /* do we have to set effective uid? */
                 uid = ruid;
                 if (sct->m_mode & S_ISUID)
-                        uid = sct->m_uid;
+                        uid = sct->m_ugid.uid;
                 /* else (no seteuid) we will set euid = ruid */
 
                 if (setresuid(-1, uid, uid))