Am Tue, 12. May 2009, 10:41:31 +0200 schrieb Jö Fahlke: > Applied is a first version of a patch to improve ifparser_init(). I didn't > use getline() after all. It compiles and I did some rudimentary testing. I'm > still working on an improvement regarding the handling of continued lines.
And here comes the improved version, which I consider final unless someone cares to comment. Bye, Jö. -- featured product: Debian GNU/Linux - http://www.debian.org
Index: network-manager-0.7.1/system-settings/plugins/ifupdown/interface_parser.c
===================================================================
--- network-manager-0.7.1.orig/system-settings/plugins/ifupdown/interface_parser.c 2009-05-12 23:11:11.000000000 +0200
+++ network-manager-0.7.1/system-settings/plugins/ifupdown/interface_parser.c 2009-05-12 23:18:35.000000000 +0200
@@ -26,6 +26,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <ctype.h>
#include "nm-utils.h"
if_block* first;
@@ -74,86 +75,266 @@
//printf("added data '%s' with key '%s'\n",data,key);
}
-#define SPACE_OR_TAB(string,ret) {ret = strchr(string,' ');ret=(ret == NULL?strchr(string,'\t'):ret);}
+
+/** Append a line read from a stream to a string
+ *
+ * Read a line from stream and append it at the location *str+*str_len. If
+ * the line terminated in a newline, it is stripped. *str_len is then updated
+ * to reflect the new size. On entrance, *str may be unterminated, but on
+ * exit it is always terminted with a newline (unless an allocation error
+ * occured).
+ *
+ * If the space available for *str is insufficient, new space is allocated
+ * using realloc(). *str_size is updated accordingly.
+ *
+ * On entrance, *str may be NULL. In this case the initial values of
+ * *str_size and *str_len don't matter and some space is allocated using
+ * malloc().
+ *
+ * On success, the return value is the number of characters read, which is
+ * usually more than the number of characters actually appended because of the
+ * newline-stripping. On error or EOF -1 is returned. The return value will
+ * never be 0 size zero characters read is interpreted as EOF.
+ *
+ * \param str Pointer to the string to be appended to.
+ * \param str_size Allocated space for the string.
+ * \param str_len Length of string.
+ * \param stream The stream to read from.
+ */
+static ssize_t append_line(char **str, size_t *str_size, size_t *str_len, FILE *stream)
+{
+
+ size_t chars_read;
+ size_t global_chars_read = 0;
+
+ if(*str == NULL)
+ {
+ char *newstr = (char *)malloc(80);
+ if(newstr == NULL)
+ return -1;
+ *str = newstr;
+ *str_size = 80;
+ *str_len = 0;
+ (*str)[0] = '\0';
+ }
+
+ do {
+ if(*str_size <= *str_len + 1)
+ {
+ char *newstr = (char *)realloc(*str, *str_size * 2);
+ if(newstr == NULL)
+ return -1;
+ *str = newstr;
+ *str_size = *str_size * 2;
+ }
+
+ if(fgets(*str+*str_len, *str_size-*str_len, stream) == NULL)
+ /* restore terminating \0 in case there was an error */
+ (*str)[*str_len] = '\0';
+ chars_read = strlen(*str+*str_len);
+ *str_len += chars_read;
+ global_chars_read += chars_read;
+ } while(chars_read > 0 && (*str)[*str_len-1] != '\n');
+
+ /* trim trailing newline */
+ if(global_chars_read > 0 && (*str)[*str_len-1] == '\n')
+ (*str)[--*str_len] = '\0';
+
+ if(global_chars_read == 0)
+ return -1;
+ return global_chars_read;
+}
+
+/** Get the next non-empty non-comment line
+ *
+ * Get the next line from stream which is neither empty nor a comment starting
+ * with '#'. Lines may be continued using '\\' just before the newline,
+ * except inside comments. The "\\\n" pair is stripped, as are trailing
+ * newlines.
+ *
+ * The line is stored in *line. The initial allocated space of line should be
+ * passed in *line_size. If this space is insufficient, new space is
+ * allocated with realloc() and *line and *line_size are updated accordingly.
+ * On exit, *line_length will contain the length of the line and *start will
+ * contain the position of the first non-whitespace character.
+ *
+ * It is permissible to pass *line == NULL. In this case the initial value of
+ * *line_size is ignored and some space is allocated first.
+ *
+ * On error, or when EOF was reached and no valid line was read, -1 is
+ * returned. In this case *line_length and *start have undefined values and
+ * *line containes garbage. *line_size will still contain the allocated size,
+ * however. If *line was initially NULL, it may be NULL on return and
+ * *linesize may still contain it's initial value.
+ *
+ * On success the return value is 0.
+ *
+ * \param line Pointer to the string to be appended to.
+ * \param line_size Allocated space for the string.
+ * \param[out] line_length Length of the line.
+ * \param[out] start Position of first non-whitespace character.
+ * \param[in] stream The stream to read from.
+ */
+static ssize_t getline_extended(char **line, size_t *line_size, size_t *line_length,
+ size_t *start, FILE *stream)
+{
+ /* loop until non-empty non-comment line was found */
+ while(1)
+ {
+ *line_length = 0;
+ *start = 0;
+ /* loop for line continuation */
+ while(1)
+ {
+ /* read a line part */
+ ssize_t ret = append_line(line, line_size, line_length, stream);
+ /* if we failed to read anything, assume EOF */
+ if(ret == -1)
+ {
+ /* either the whole line is empty, then we don't have a
+ line to return */
+ if((*line)[*start] == '\0')
+ return -1;
+ /* or we do return what we have so far */
+ else
+ return 0;
+ }
+
+ /* trim leading whitespace */
+ while(isspace((*line)[*start]))
+ ++*start;
+
+ /* skip comments and empty lines */
+ if ((*line)[*start] == '#' || (*line)[*start] == '\0')
+ break;
+
+ /* check for line continuation */
+ /* no need to check whether *line_length == 0, we already
+ excluded that possiblity when we checked for empty lines
+ above */
+ if((*line)[*line_length-1] != '\\')
+ return 0; /* no continuation */
+
+ /* continuation */
+ --*line_length;
+ /* no need to truncate line, append_line cares abount
+ *line_length only anyway. */
+ }
+ }
+}
void ifparser_init(void)
{
FILE *inp = fopen(ENI_INTERFACES_FILE, "r");
- int ret = 0;
- char *line;
- char *space;
- char rline[255];
+ ssize_t ret = 0;
+ char *line = NULL;
+ size_t line_space = 0; /* reserved space for line */
+ size_t line_length; /* actual string length of line */
+ size_t word1, word1_end;
+ size_t word2;
+ size_t line_end;
if (inp == NULL)
{
nm_warning ("Error: Can't open %s\n", ENI_INTERFACES_FILE);
return;
}
- first = last = NULL;
+
while(1)
{
- line = space = NULL;
- ret = fscanf(inp,"%255[^\n]\n",rline);
- if (ret == EOF)
- break;
- // If the line did not match, skip it
- if (ret == 0) {
- char *ignored;
+ line_length = 0;
+ word1 = 0;
- ignored = fgets(rline, 255, inp);
+ ret = getline_extended(&line, &line_space, &line_length, &word1, inp);
+ if(ret == -1)
+ break; /* failed to read line; probably EOF */
+
+ /* find end of first word */
+ word1_end = word1;
+ while(line[word1_end] != '\0' && !isspace(line[word1_end]))
+ ++word1_end;
+ /* find beginning of second word */
+ word2 = word1_end;
+ while(isspace(line[word2]))
+ ++word2;
+ /* skip line if there is no second word */
+ if(line[word2] == '\0')
+ {
+ nm_warning ("Error: Can't parse interface line '%s'\n",line);
continue;
}
- line = rline;
- while(line[0] == ' ')
- line++;
- if (line[0]=='#' || line[0]=='\0')
- continue;
-
- SPACE_OR_TAB(line,space)
- if (space == NULL)
- {
- nm_warning ("Error: Can't parse interface line '%s'\n",line);
- continue;
- }
- space[0] = '\0';
+ /* trim end of line */
+ line_end = line_length-1;
+ while(isspace(line[line_end]))
+ --line_end;
+ ++line_end;
// There are four different stanzas:
// iface, mapping, auto and allow-*. Create a block for each of them.
- if (strcmp(line,"iface")==0)
+ if (word1_end == word1+5 && strncmp(line+word1,"iface",5)==0)
{
- char *space2 = strchr(space+1,' ');
- if (space2 == NULL)
+ size_t word2_end;
+ size_t word3, word3_end;
+ size_t word4;
+
+ /* find end of second word */
+ word2_end = word2;
+ while(line[word2_end] != '\0' && !isspace(line[word2_end]))
+ ++word2_end;
+
+ /* find beginning of third word */
+ word3 = word2_end;
+ while(isspace(line[word3]))
+ ++word3;
+ if (line[word3] == '\0')
{
- nm_warning ("Error: Can't parse iface line '%s'\n",space+1);
+ nm_warning ("Error: Can't parse iface line '%s'\n",line);
continue;
}
- space2[0]='\0';
- add_block(line,space+1);
- if (space2[1]!='\0')
+ /* find end of third word */
+ word3_end = word3;
+ while(line[word3_end] != '\0' && !isspace(line[word3_end]))
+ ++word3_end;
+
+ /* find beginning of fourth word */
+ word4 = word3_end;
+ while(isspace(line[word4]))
+ ++word4;
+ if (line[word4] == '\0')
{
- space = strchr(space2+1,' ');
- if (space == NULL)
- {
- nm_warning ("Error: Can't parse data '%s'\n",space2+1);
- continue;
- }
- space[0] = '\0';
- add_data(space2+1,space+1);
+ nm_warning ("Error: Can't parse iface line '%s'\n",line);
+ continue;
}
+
+ /* no more error-printing to be done here, we can modify line */
+ /* add block with i.e. "iface" "eth0" */
+ line[word1_end] = '\0';
+ line[word2_end] = '\0';
+ add_block(line+word1, line+word2);
+
+ /* add data with i.e. "inet" "dhcp" */
+ line[word3_end] = '\0';
+ line[line_end] = '\0';
+ add_data(line+word3, line+word4);
}
- else if (strcmp(line,"auto")==0)
- add_block(line,space+1);
- else if (strcmp(line,"mapping")==0)
- add_block(line,space+1);
- else if (strncmp(line,"allow-",6)==0)
- add_block(line,space+1);
else
- add_data(line,space+1);
+ {
+ /* no more error-printing to be done here, we can modify line */
+ line[word1_end] = '\0';
+ line[line_end] = '\0';
+ if(strcmp(line+word1,"auto")==0 ||
+ strcmp(line+word1,"mapping")==0 ||
+ strncmp(line+word1,"allow-",6)==0)
+ add_block(line+word1, line+word2);
+ else
+ add_data(line+word1, line+word2);
+ }
- //printf("line: '%s' ret=%d\n",rline,ret);
}
+
+ free(line);
fclose(inp);
}
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