sfeed

simple feed reader - forked from git.codemadness.org/sfeed
git clone git://src.gearsix.net/sfeed
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commit e3df66af907f6f14b2bd9176285701fa94bac81a
parent 921eb9b5db37cb6e8d463b9a0aee085c8c453c50
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sun,  4 Jan 2015 18:54:06 +0100

snprintf() truncation checks

Diffstat:
Msfeed.c | 11+++++++----
Msfeed_frames.c | 35++++++++++++++++++++++-------------
2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/sfeed.c b/sfeed.c @@ -360,8 +360,8 @@ parsetime(const char *s, char *buf, size_t bufsiz, time_t *tp) NULL }; char *p; - unsigned int i; - int tzoffset; + size_t i; + int tzoffset, r; memset(&tm, 0, sizeof(tm)); for(i = 0; formats[i]; i++) { @@ -372,11 +372,14 @@ parsetime(const char *s, char *buf, size_t bufsiz, time_t *tp) return -1; if(gettimetz(p, tz, sizeof(tz), &tzoffset) != -1) t -= tzoffset; - if(buf) - snprintf(buf, bufsiz, + if(buf) { + r = snprintf(buf, bufsiz, "%04d-%02d-%02d %02d:%02d:%02d %s", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, tz); + if(r == -1 || (size_t)r >= bufsiz) + return -1; /* truncation */ + } if(tp) *tp = t; return 0; diff --git a/sfeed_frames.c b/sfeed_frames.c @@ -52,6 +52,22 @@ xerr(int eval, const char *fmt, ...) va_end(ap); } +static int +esnprintf(char *str, size_t size, const char *fmt, ...) +{ + va_list ap; + int r; + + va_start(ap, fmt); + r = vsnprintf(str, size, fmt, ap); + va_end(ap); + + if(r == -1 || (size_t)r >= size) + xerr(1, "snprintf"); + + return r; +} + /* print text, ignore tabs, newline and carriage return etc * print some HTML 2.0 / XML 1.0 as normal text */ static void @@ -125,18 +141,14 @@ main(int argc, char *argv[]) basepathlen = strlen(basepath); if(basepathlen > 0) mkdir(basepath, S_IRWXU); - /* write main index page */ - if(snprintf(dirpath, sizeof(dirpath), "%s/index.html", basepath) <= 0) - xerr(1, "snprintf"); + esnprintf(dirpath, sizeof(dirpath), "%s/index.html", basepath); if(!(fpindex = fopen(dirpath, "w+b"))) xerr(1, "fopen"); - if(snprintf(dirpath, sizeof(dirpath), "%s/menu.html", basepath) <= 0) - xerr(1, "snprintf"); + esnprintf(dirpath, sizeof(dirpath), "%s/menu.html", basepath); if(!(fpmenu = fopen(dirpath, "w+b"))) xerr(1, "fopen: can't write menu.html"); - if(snprintf(dirpath, sizeof(dirpath), "%s/items.html", basepath) <= 0) - xerr(1, "snprintf"); + esnprintf(dirpath, sizeof(dirpath), "%s/items.html", basepath); if(!(fpitems = fopen(dirpath, "w+b"))) xerr(1, "fopen"); fputs("<html><head><link rel=\"stylesheet\" type=\"text/css\" href=\"../style.css\" />" @@ -160,8 +172,7 @@ main(int argc, char *argv[]) if(!(namelen = makepathname(feedname, name, sizeof(name)))) continue; - if(snprintf(dirpath, sizeof(dirpath), "%s/%s", basepath, name) <= 0) - xerr(1, "snprintf"); + esnprintf(dirpath, sizeof(dirpath), "%s/%s", basepath, name); /* directory doesn't exist: try to create it. */ if(stat(dirpath, &st) == -1 && mkdir(dirpath, S_IRWXU) == -1) @@ -198,10 +209,8 @@ main(int argc, char *argv[]) /* write content */ if(!(namelen = makepathname(fields[FieldTitle], name, sizeof(name)))) continue; - if(snprintf(filepath, sizeof(filepath), "%s/%s.html", dirpath, name) <= 0) - xerr(1, "snprintf"); - if(snprintf(relfilepath, sizeof(relfilepath), "%s/%s.html", reldirpath, name) <= 0) - xerr(1, "snprintf"); + esnprintf(filepath, sizeof(filepath), "%s/%s.html", dirpath, name); + esnprintf(relfilepath, sizeof(relfilepath), "%s/%s.html", reldirpath, name); /* file doesn't exist yet and has write access */ if(access(filepath, F_OK) != 0 && (fpcontent = fopen(filepath, "w+b"))) {