file: fix segfault in uci_parse_config

[project/uci.git] / file.c

diff --git a/file.c b/file.c
index 341a7065cddd4e352aae360d596e651d694359c6..3cd7702fe260e85b3368848791472d1419eab2f9 100644 (file)
--- a/file.c
+++ b/file.c
@@ -28,6 +28,7 @@
 #include <glob.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 
 #include "uci.h"
 #include "uci_internal.h"
@@ -70,8 +71,6 @@ __private void uci_getln(struct uci_context *ctx, int offset)
 
                pctx->bufsz *= 2;
                pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
-               if (!pctx->buf)
-                       UCI_THROW(ctx, UCI_ERR_MEM);
        } while (1);
 }
 
@@ -410,7 +409,6 @@ static void uci_parse_config(struct uci_context *ctx)
        char *name;
        char *type;
 
-       uci_fixup_section(ctx, ctx->pctx->section);
        if (!ctx->pctx->package) {
                if (!ctx->pctx->name)
                        uci_parse_error(ctx, "attempting to import a file without a package name");
@@ -427,9 +425,9 @@ static void uci_parse_config(struct uci_context *ctx)
                uci_parse_error(ctx, "invalid character in type field");
 
        ofs_name = next_arg(ctx, false, true, false);
+       assert_eol(ctx);
        type = pctx_str(pctx, ofs_type);
        name = pctx_str(pctx, ofs_name);
-       assert_eol(ctx);
 
        if (!name || !name[0]) {
                ctx->internal = !pctx->merge;
@@ -437,8 +435,13 @@ static void uci_parse_config(struct uci_context *ctx)
        } else {
                uci_fill_ptr(ctx, &ptr, &pctx->package->e);
                e = uci_lookup_list(&pctx->package->sections, name);
-               if (e)
+               if (e) {
                        ptr.s = uci_to_section(e);
+
+                       if ((ctx->flags & UCI_FLAG_STRICT) && strcmp(ptr.s->type, type))
+                               uci_parse_error(ctx, "section of different type overwrites prior section with same name");
+               }
+
                ptr.section = name;
                ptr.value = type;
 
@@ -566,7 +569,7 @@ static const char *uci_escape(struct uci_context *ctx, const char *str)
                len = end - str;
 
                /* make sure that we have enough room in the buffer */
-               while (ofs + len + sizeof(UCI_QUOTE_ESCAPE) + 1 > ctx->bufsz) {
+               while (ofs + len + (int) sizeof(UCI_QUOTE_ESCAPE) + 1 > ctx->bufsz) {
                        ctx->bufsz *= 2;
                        ctx->buf = uci_realloc(ctx, ctx->buf, ctx->bufsz);
                }
@@ -686,7 +689,6 @@ error:
                        UCI_THROW(ctx, ctx->err);
        }
 
-       uci_fixup_section(ctx, ctx->pctx->section);
        if (!pctx->package && name)
                uci_switch_config(ctx);
        if (package)
@@ -719,11 +721,11 @@ static void uci_file_commit(struct uci_context *ctx, struct uci_package **packag
 {
        struct uci_package *p = *package;
        FILE *f1, *f2 = NULL;
-       char *name = NULL;
-       char *path = NULL;
+       char *volatile name = NULL;
+       char *volatile path = NULL;
        char *filename = NULL;
-       struct stat statbuf;
-       bool do_rename = false;
+       volatile bool do_rename = false;
+       int fd;
 
        if (!p->path) {
                if (overwrite)
@@ -735,17 +737,6 @@ static void uci_file_commit(struct uci_context *ctx, struct uci_package **packag
        if ((asprintf(&filename, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name) < 0) || !filename)
                UCI_THROW(ctx, UCI_ERR_MEM);
 
-       if (!mktemp(filename))
-               *filename = 0;
-
-       if (!*filename) {
-               free(filename);
-               UCI_THROW(ctx, UCI_ERR_IO);
-       }
-
-       if ((stat(filename, &statbuf) == 0) && ((statbuf.st_mode & S_IFMT) != S_IFREG))
-               UCI_THROW(ctx, UCI_ERR_IO);
-
        /* open the config file for writing now, so that it is locked */
        f1 = uci_open_stream(ctx, p->path, NULL, SEEK_SET, true, true);
 
@@ -780,7 +771,20 @@ static void uci_file_commit(struct uci_context *ctx, struct uci_package **packag
                        goto done;
        }
 
-       f2 = uci_open_stream(ctx, filename, p->path, SEEK_SET, true, true);
+       fd = mkstemp(filename);
+       if (fd == -1)
+               UCI_THROW(ctx, UCI_ERR_IO);
+
+       if ((flock(fd, LOCK_EX) < 0) && (errno != ENOSYS))
+               UCI_THROW(ctx, UCI_ERR_IO);
+
+       if (lseek(fd, 0, SEEK_SET) < 0)
+               UCI_THROW(ctx, UCI_ERR_IO);
+
+       f2 = fdopen(fd, "w+");
+       if (!f2)
+               UCI_THROW(ctx, UCI_ERR_IO);
+
        uci_export(ctx, f2, p, false);
 
        fflush(f2);
@@ -795,9 +799,13 @@ done:
        free(name);
        free(path);
        uci_close_stream(f1);
-       if (do_rename && rename(filename, p->path)) {
-               unlink(filename);
-               UCI_THROW(ctx, UCI_ERR_IO);
+       if (do_rename) {
+               path = realpath(p->path, NULL);
+               if (!path || rename(filename, path)) {
+                       unlink(filename);
+                       UCI_THROW(ctx, UCI_ERR_IO);
+               }
+               free(path);
        }
        free(filename);
        if (ctx->err)
@@ -826,7 +834,8 @@ static char **uci_list_config_files(struct uci_context *ctx)
 {
        char **configs;
        glob_t globbuf;
-       int size, i;
+       int size, j, skipped;
+       size_t i;
        char *buf;
        char *dir;
 
@@ -838,18 +847,22 @@ static char **uci_list_config_files(struct uci_context *ctx)
        }
 
        size = sizeof(char *) * (globbuf.gl_pathc + 1);
+       skipped = 0;
        for(i = 0; i < globbuf.gl_pathc; i++) {
                char *p;
 
                p = get_filename(globbuf.gl_pathv[i]);
-               if (!p)
+               if (!p) {
+                       skipped++;
                        continue;
+               }
 
                size += strlen(p) + 1;
        }
 
-       configs = uci_malloc(ctx, size);
-       buf = (char *) &configs[globbuf.gl_pathc + 1];
+       configs = uci_malloc(ctx, size - skipped);
+       buf = (char *) &configs[globbuf.gl_pathc + 1 - skipped];
+       j = 0;
        for(i = 0; i < globbuf.gl_pathc; i++) {
                char *p;
 
@@ -860,7 +873,7 @@ static char **uci_list_config_files(struct uci_context *ctx)
                if (!uci_validate_package(p))
                        continue;
 
-               configs[i] = buf;
+               configs[j++] = buf;
                strcpy(buf, p);
                buf += strlen(buf) + 1;
        }
@@ -869,12 +882,13 @@ static char **uci_list_config_files(struct uci_context *ctx)
        return configs;
 }
 
-static struct uci_package *uci_file_load(struct uci_context *ctx, const char *name)
+static struct uci_package *uci_file_load(struct uci_context *ctx,
+                                        const char *volatile name)
 {
        struct uci_package *package = NULL;
        char *filename;
        bool confdir;
-       FILE *file = NULL;
+       FILE *volatile file = NULL;
 
        switch (name[0]) {
        case '.':