From c65427deabcee4cef1cdf83a129b50e94f645dec Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Fri, 11 Mar 2016 16:01:24 +0100 Subject: [PATCH] Add modify_config_file() to allow overwriting existing configuration values. --- src/conf.c | 152 ++++++++++++++++++++++++++--------------------------- src/conf.h | 2 +- 2 files changed, 75 insertions(+), 79 deletions(-) diff --git a/src/conf.c b/src/conf.c index ef595efc..af8b0b0e 100644 --- a/src/conf.c +++ b/src/conf.c @@ -18,6 +18,7 @@ */ #include "system.h" +#include #include "splay_tree.h" #include "connection.h" @@ -387,115 +388,110 @@ bool write_host_config(struct meshlink_handle *mesh, const struct splay_tree_t * return write_config_file(config_tree, filename); } -bool change_config_file(meshlink_handle_t *mesh, const char *name, const char *key, const char *value) { +bool modify_config_file(struct meshlink_handle *mesh, const char *name, const char *key, const char *value, bool replace) { + assert(mesh && name && key && (replace || value)); + char filename[PATH_MAX]; char tmpname[PATH_MAX]; - char buf[MAX_STRING_SIZE]; - const int keylen = strlen(key); + bool error = false; + + snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name); + snprintf(tmpname, sizeof tmpname, "%s.tmp", filename); - snprintf(filename, PATH_MAX, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name); - snprintf(tmpname, PATH_MAX, "%s.tmp", filename); + FILE *fr = fopen(filename, "r"); - FILE *in = fopen(filename, "r"); - if(!in) { - // Hm, maybe the file does not exist? Try appending. - return append_config_file(mesh, name, key, value); + if(!fr) { + logger(mesh, MESHLINK_ERROR, "Cannot open config file %s: %s", filename, strerror(errno)); + return false; } - FILE *out = fopen(tmpname, "w"); - if(!out) { - logger(mesh, MESHLINK_ERROR, "Failed to write `%s': %s", tmpname, strerror(errno)); - fclose(in); + FILE *fw = fopen(tmpname, "w"); + + if(!fw) { + logger(mesh, MESHLINK_ERROR, "Cannot open temporary file %s: %s", tmpname, strerror(errno)); + fclose(fr); return false; } - bool ignore = false; + char buf[4096]; + char *sep; + bool found = false; - while(readline(in, buf, sizeof buf)) { - if(ignore) { - if(!strncmp(buf, "-----END", 8)) - ignore = false; - } else { - if(!strncmp(buf, "-----BEGIN", 10)) - ignore = true; + while(readline(fr, buf, sizeof buf)) { + if(!*buf || *buf == '#') + goto copy; + + sep = strchr(buf, ' '); + if(!sep) + goto copy; + + *sep = 0; + if(strcmp(buf, key)) { + *sep = ' '; + goto copy; } - if(!ignore && !strncmp(buf, key, keylen)) { - if(strchr("\t =", buf[keylen])) { + if(!value) { + found = true; + continue; + } + + // We found the key and the value. Keep one copy around. + if(sep[1] == '=' && sep[2] == ' ' && !strcmp(sep + 3, value)) { + if(found) continue; - } + found = true; } - fputs(buf, out); - fputc('\n', out); - } + // We found the key but with a different value, delete it if wanted. + if(!found && replace) + continue; - if(ferror(in)) { - logger(mesh, MESHLINK_ERROR, "Failed to read `%s': %s", filename, strerror(errno)); - fclose(in); - fclose(out); - return false; + *sep = ' '; + +copy: + fprintf(fw, "%s\n", buf); } - fclose(in); + if(ferror(fr)) + error = true; + + fclose(fr); - fprintf(out, "%s = %s\n", key, value); + // Add new key/value pair if necessary + if(!found && value) + fprintf(fw, "%s = %s\n", key, value); - if(ferror(out)) { - logger(mesh, MESHLINK_ERROR, "Failed to write `%s': %s", tmpname, strerror(errno)); - fclose(out); + if(ferror(fw)) + error = true; + + if(fclose(fw)) + error = true; + + // If any error occured during reading or writing, exit. + if(error) { + unlink(tmpname); return false; } - fclose(out); - + // Try to atomically replace the old config file with the new one. #ifdef HAVE_MINGW - // We cannot atomically replace files on Windows. char bakname[PATH_MAX]; - snprintf(bakname, PATH_MAX, "%s.bak", filename); - if(rename(tmpname, bakfile) || rename(bakfile, filename)) { - rename(bakfile, filename); + snprintf(bakname, sizeof bakname, "%s.bak", filename); + if(rename(filename, bakname) || rename(tmpname, filename)) { + rename(bakname, filename); #else if(rename(tmpname, filename)) { #endif - logger(mesh, MESHLINK_ERROR, "Failed to update `%s': %s", filename, strerror(errno)); return false; + } else { +#ifdef HAVE_MINGW + unlink(bakname); +#endif + return true; } - - return true; } bool append_config_file(meshlink_handle_t *mesh, const char *name, const char *key, const char *value) { - char filename[PATH_MAX]; - snprintf(filename,PATH_MAX, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name); - - FILE *fp = fopen(filename, "a"); - - if(!fp) { - logger(mesh, MESHLINK_ERROR, "Cannot open config file %s: %s", filename, strerror(errno)); - return false; - } - - // Check if we don't add a duplicate entry - - char entry[MAX_STRING_SIZE]; - snprintf(entry, sizeof entry, "%s = %s", key, value); - - char buffer[MAX_STRING_SIZE]; - bool found = false; - - while(readline(fp, buffer, sizeof buffer)) { - if(!strcmp(buffer, entry)) { - found = true; - break; - } - } - - // If not, append the new entry - - if(!found) - fprintf(fp, "%s\n", entry); - - fclose(fp); - return true; + return modify_config_file(mesh, name, key, value, false); } diff --git a/src/conf.h b/src/conf.h index b1e50c77..46f1c89e 100644 --- a/src/conf.h +++ b/src/conf.h @@ -52,7 +52,7 @@ extern bool write_config_file(const struct splay_tree_t *, const char *); extern bool read_server_config(struct meshlink_handle *mesh); extern bool read_host_config(struct meshlink_handle *mesh, struct splay_tree_t *, const char *); extern bool write_host_config(struct meshlink_handle *mesh, const struct splay_tree_t *, const char *); -extern bool change_config_file(struct meshlink_handle *mesh, const char *, const char *, const char *); +extern bool modify_config_file(struct meshlink_handle *mesh, const char *, const char *, const char *, bool); extern bool append_config_file(struct meshlink_handle *mesh, const char *, const char *, const char *); #endif /* __MESHLINK_CONF_H__ */ -- 2.39.2